Cancer: Gene Therapies, Stem Cells, Telomeres, and Cytokines

The media reports on many medical breakthroughs but usually issues a disclaimer stating that it will take many years before the discovery becomes part of standard practice. Interestingly, there are steps a cancer patient can take right now to gain access to this state-of-the-art knowledge. In some instances, a patient will have to travel to a research facility. In other cases, these therapies can be incorporated into a cancer treatment program utilizing existing therapeutic approaches.

We describe some of these exciting advances in this protocol and reveal how cancer patients may take advantage of them today. It is important to caution that the information provided in this chapter is highly technical and some lay readers may have difficulty fully understanding it.

How Genes Control Cancer Cells

One of the main categories of genes responsible for cancer includes those that (when working properly) suppress the development of malignancies. Various cancers result from the loss or malfunction of the key regulatory proteins that tumor suppressor genes encode, primarily p53 and pRB proteins. (pRB is named from retinoblastoma, the type of tumor in which its gene, RB, was first identified.) In its active form, pRB serves as a brake on DNA replication, blocking the activity of another protein (E2F) which promotes the synthesis of DNA. Loss of pRB protein therefore leads to uncontrolled E2F action and rampant cell division. Research indicates the RB gene is mutated in about 40% of human cancers, rendering its protein inactive (Oliff et al. 1996).

Another infinitely important regulatory molecule is the p53 protein. Often called the guardian of the genome, p53 prevents replication of damaged DNA in normal cells and promotes suicide or apoptosis of cells with abnormal DNA (Oliff et al. 1996). Faulty p53 molecules allow cells (carrying damaged DNA) to survive when they would normally die and to replicate when they would normally stop. Cell cycle constraints are when pass, repair, and apoptotic mechanisms falter and disturbed cells pass mutations down to offspring. Thus, a lack of p53 regulation promotes the spontaneous emergence of mutant cells, a cellular distortion that is an invitation to cancer (Greenblatt et al. 1994).

Researchers compared the expression of more than 7000 genes and found that about 30 genes are activated by p53; the 14 most often stimulated by p53 are involved in cell regulation. The inactivation of the p53 gene is observed in about 50% of all solid tumors, affording prognostic and therapeutic implications. For example, researchers from the Mayo Clinic announced that analyzing p53 gene mutations identifies a subset of breast cancer patients who, despite lack of conventional indications of poor prognosis, are at high risk of early disease recurrence and death (Blaszyk et al. 2000).

Therapeutically, studies demonstrate that injecting wild type p53 into a malignant cell has positive effects when the p53 gene is either absent or mutated. In a 3-month study, nine men with advanced lung cancer (displaying a mutation in the tumor suppressor gene p53) were injected with healthy copies (genetically engineered) once a day for 5 days. The lung tumors treated with the p53 solution stopped growing in three patients; regression occurred in another three. Although all of the subjects eventually failed treatment, the major finding from the study, that is, "proof of principle," suggests that gene therapy can be an effective way to halt tumor cell growth (Modica et al. 1996). This therapeutic approach may have a potential application in at least 50% of all human tumors.

The highest frequency of p53 mutations reported in human cancers are lung, 56%; colon, 50%; esophagus, 45%; ovary, pancreas, and skin, 44%; stomach, 41%; head and neck, 37%; bladder, 34%; prostate, 30%; and breast, endometrial, and mesothelioma, 22% (Greenblatt et al. 1994). Nearly 20% of women treated for ovarian cancer develop other tumors beyond the abdomen. A mutation in the p53 tumor suppressor gene appears to predispose some women with ovarian cancer to distant and rapid tumor spread, according to data from the University of Iowa Health Care Study .

A mutant p53 gene seems able to escape destruction even when confronted with normally lethal concentrations of cytotoxic drugs and ionizing radiation (Buttitta et al. 1997). Furthermore, a dysfunctional p53 gene affects the outcome of traditional therapies because toxic treatments depend upon DNA damage and p53-induced cell death. The p53 gene induces cells to kill themselves by producing free radicals (charged molecules) causing cellular oxidation. Oxidation damages protein as well as the membranes and eventually the cell dies ( Choisy-Rossi et al 1998).

The character and therapeutic value of p53 is illustrated in the following studies:

• The tumors of 30 patients were directly injected with the p53 gene. Among 17 patients with nonresectable tumors, five stabilized and two exhibited partial regression (defined as at least a 50% reduction in the size of the mass). Among the 13 patients with resectable tumors, three died of their cancer, and five (38%) remained free of disease for 6 months post injection ( Kigawa et al. 2000).
• Progesterone induces apoptosis and markedly upregulates p53 expression in ovarian cell lines. It is, thus, suspected that p53 plays a significant role in progesterone-induced apoptosis (Bu et al. 1997).
• Australian researchers found that interactions between telomerase and p53 indicate the activity of telomerase may be regulated by p53; downregulation of p53 would (in turn) favor upregulation of telomerase activity in cancer cell development (Li et al. 1999). Please consult the Telomere/Telomerase Connection appearing later in this protocol for additional information.
• Vitamin E, in combination with vitamins A and C, led to a four-fold reduction in p53 mutations (Brotzman et al. 1999).

Part of the body's natural defense against cancer may have a downside. Mice with high activity of the tumor-suppressing p53 gene had low rates of cancer, but aged prematurely. The surprise finding suggests that aging might occur, in part, because of the body's innate vigilance against cancer. Mutant mice with "revved up" p53 were more resistant to cancer than normal mice, but despite this protection, the mutant mice had (roughly) a 20% shorter lifespan. Instead of cancer, the animals experienced bone thinning, organ breakdown, vulnerability to physical stress, and the equivalent of sagging skin and balding in humans. Researchers speculate that hyperactivity in the p53 gene may disable the body's reserve of stem cells sooner than normal. This would keep primitive cells from replenishing certain body tissues and lead to premature tissue degeneration (Ferbeyre et al. 2002).

Protein Kinase Inhibitors
According to the Laboratory of Molecular Biophysics, of the hundreds of protein kinases in the human genome, only about 27 protein kinase structures have been solved to date. Yet, so important are the family of kinases, oncogenes that encode (program) protein kinases are under ongoing study for their participation in cancer (Johnson 2002). In normal cells, protein kinases are involved in signals sent between the cell membrane and the nucleus, regulating progression through the cell cycle. Protein kinases control these processes by activating other proteins in response to stimuli. Mutated kinase genes have been found in a number of malignancies, including chronic myelogenous leukemia and breast and bladder cancers.

Kinases can lead to cancer though various pathways including overproduction, an event caused by mutations in the control regions of their genes. Compared to normal cells, tumor cells often overproduce kinases, encouraging the cell to divide. A commonly overproduced kinase in cancerous tissue is the receptor for epidermal growth factor (EGF), an upregulation strongly favoring cancer.

Kinases can also contribute to cancer if their structure is abnormal. Many tumor cells possess protein kinases that (because of a structural defect) are permanently turned on, goading the cell into division. Examples of kinases that behave abnormally in certain human cancers are the Abl, Src, and cyclin-dependent kinases (Oliff et al. 1996).

Obviously, an inhibitor of dysfunctional kinases is a worthy cancer therapy research objective. The challenge is finding a substance that can distinguish one kinase from another. Many of the protein kinases in mammalian cells have similar structures, particularly in biochemically active regions. Hence, an inhibitor of any single protein kinase might disrupt the activity of others, that is, an unrelated kinase crucial to normal cell function.

Despite limitations, pharmaceutical researchers have synthesized and tested a number of kinase inhibitors. Most target the kinases themselves, but others attack at the genetic level (preventing the kinases from being formed). Remarkably, kinase inhibitors can be quite selective. In the test tube, some find their intended target 1000 times more frequently than they do unrelated kinases. More important are findings that several of these compounds inhibit the growth of cancer cells possessing mutated kinase genes.

Various natural agents appear able to inhibit protein kinase activity:

• Flavonoid analogues inhibit protein-tyrosine kinase. The most active substance used in this study was compound 17c, which is approximately one order greater in potency than quercetin. After a series of reduction mechanisms, 3-(alkoxycarbonyl)-2-arylflavones is produced and then converted to a variety of flavonoids, including 17c (Cushman et al. 1991).
• Genistein and daidzein, isoflavones found in soy, are specific inhibitors of protein tyrosine kinase (PTK). By modulating pathways involved in signal transduction, isoflavones acting upon PTK put the brakes on rapidly dividing cells (Bland 2001).
• Oxidants selectively react with the regulatory center of protein kinase C (PKC), signaling tumor promotion and cell growth. In contrast, antioxidants (selenium and polyphenolic agents, such as curcumin, and vitamin E analogues) inhibit cellular PKC activity and thus interfere with the action of tumor promoters (Gopalakrishna et al. 2000). Other polyphenolic phytochemicals, that is, the constituents of green tea and resveratrol, respond similarly, displaying significant PKC inhibition (Stoner et al. 1995; Atten et al. 2001).
• As protein kinase C (PKC) is stimulated, tumor activity in the colon increases. Retinol, retinoic acid, and beta-carotene (in nanomolar concentrations) block stimulation of PKC. At higher doses, retinol and retinoic acid can stimulate kinase activity; beta-carotene does not have this effect and could thus be useful in the prevention and treatment of colorectal cancer (Kahl-Rainer et al. 1994).

This growing body of knowledge about the effect of kinases on cell regulatory genes helps explain why soy extracts (genistein and daidzein), curcumin, beta-carotene, and certain types of vitamin E have anticancer effects. The problem is that we don't have precise data to predict how a particular dose of a protein kinase C inhibiting agent will affect gene expression on cancer cells. There are findings, however, from related studies indicating that the following doses of nutrients might be beneficial in suppressing protein kinase C that is involved in controlling cancer cell propagation:

• Curcumin, 3600 mg a day
• Genistein, 2700 mg a day
• Tocopheryl succinate, 800 mg a day
• Beta-carotene, 25,000 IU a day
• Retinal palmitate, 25,000 IU a day

The Telomere/Telomerase Connection

One of the crucial features that distinguish a cancer cell from a normal cell is its ability to divide indefinitely. Telomerase, an enzyme in the cell nucleus, is intricately involved in the cancer process through interactions with telomeres, the protective structures at the ends of chromosomes. In most normal human cells, the action of telomerase is repressed and subsequently telomeres shorten progressively with each cell division. In contrast, most human tumors utilize telomerase, resulting in stabilized telomere length. For tumor cells to proliferate, they must maintain the telomeres. Thus, cancer cells turn on genes responsible for telomerase production which in humans normally ceases after birth. Suppressing telomerase is an obvious target for the development of anticancer therapies (Hahn et al. 1999).

Telomerase is composed of at least two units: hTR and hTRT, genes whose activity correlate with the malignancy and metastatic potential of the tumor. The combination of hTR and hTRT activates telomerase, lengthening telomeres and extending the cell's replicative lifespan. hTR and hTRT were detected in 85% and 82% of primary tumors, respectively; in surrounding, healthier tissue, the positive incidence of hTR/hTRT was only ~3% (Bodnar et al. 1998; Yuan et al. 2000).

Because telomerase activity is increased in the vast majority of human tumors (about 90%), its gene product appears to be the first molecule common to all tumors (Cairns et al. 2000; Minev et al. 2000). In analyzing human cancers, the positive frequency of hTR and hTRT was overwhelmingly displayed in cancers of the breast, colon, gallbladder, lung, stomach, and esophagus. Telomere length and telomerase activity are also evidenced in chronic lymphocytic leukemia, often proving predictive of survival (Bechter et al. 1998). In addition, multiple myeloma patients with high levels of telomerase activity were also found to have a significantly shorter survival time. Telomerase, thus, is proving a reliable marker for the proliferating capacity and tumor mass of cancer patients (Shiratsuchi et al. 2002).

Retinoids employ two different pathways to impact telomerase activity; the second means (downregulating hTRT) results in a suppression of telomerase that develops slowly during 2 weeks of retinoic acid therapy, terminating in telomere shortening, growth arrest, and cell death. Telomerase expression is an efficient and selective target of retinoids in the therapy of tumors (Pendino et al. 2001).

Retinoids are not alone in their capacity to inhibit telomerase.

• Epigallocatechin gallate (EGCG), a green tea catechin, strongly and directly inhibited telomerase (Naasani et al. 1998).
• Antioxidants reduce telomerase activity ( Liu et al 2002)
• Administering NSAIDs (indomethacin and ibuprofen) resulted in a dose-dependent reduction in telomerase activity (Thurnher et al. 2001).
• Scientists from USCD School of Medicine and Cancer Center in corroboration with the Institute Pasteur in Paris are successfully using telomerase in a prototype vaccine to activate cytotoxic T-lymphocytes. By immunizing lymphocytes against telomerase, killer cells targeting telomerase are generated. The vaccine specifically targets the hTRT peptide, and the proliferative patterns common to immortal cells are destroyed (Zanetti et al. 2000). Researchers ( University of California ) suggest that hTRT has the potential to serve as a universal cancer vaccine (Minev et al. 2000).

Two pharmaceutical groups (Geron Corporation and Ribozyme Pharmaceuticals) have joined forces to elaborate GRN163, a short, modified oligonucleotide designed as a telomerase antagonist. A Geron Corporation spokesperson said that inhibiting telomerase represents a novel mechanism for the treatment of cancer with potentially broader utility and greater selectivity against cancer cells than currently available agents. The companies are also exploring a ribozyme-based telomerase inhibitor with apoptotic activity, as well as the ability to shorten telomeres (BW 2001). Isolating anticancer drugs targeted at telomerase inhibition is a global effort, one considered crucial to understanding and subsequently overcoming cancer.

Telomerase inhibitors are exciting potential therapies against cancer (Cairns et al 2002; Mokbel 2003). Several human clinical trials are expected in the year 2004. A Phase II clinical trial for individuals fighting metastatic cancer using a vaccine that contains a telomerase peptide (piece of a telomerase protein) is currently underway at the National Cancer Institute: http://clinicaltrials.gov/ct/show/NCT00016640?order=1

Although much of this work is still in the research phase, there is evidence that high-dose green tea extract and retinoid compounds may inhibit the telomerase enzyme that allows cancer cells to proliferate out of control ( L'Allemain 1999; Pendino et al 2003) . You may consider one or both of the following potential telomerase-inhibiting therapies available right now:

• Vesanoid (all-trans retinoic acid) is a drug already approved to treat certain cancers ( Ozpolat et al 2001) . Based on its potential telomerase-inhibiting property, you may want to ask your oncologist to prescribe an individualized dose for you.
• High-potency green tea extracts are available as dietary supplements. A dose used by some cancer patients is five 350-mg capsules of green tea (95%) extract with each meal (3 meals per day). Each capsule should be standardized to provide a minimum of 100 mg of epigallocatechin gallate (EGCG). It is the EGCG fraction of green tea that has shown the most active anticancer effects. These high-potency green tea extract capsules are available in decaffeinated form for those who are sensitive to caffeine or who want to take the less stimulating decaffeinated green tea extract capsules in their evening dose. The brand name of the 95% green tea extract is Super Green Tea Extract Caps.

For information regarding telomerase-inhibiting drug clinical trials, call the National Cancer Institute (NCI) at (800) 422-7237 or visit the NCI's clinical trials Web site. One company that may start clinical trials in 2004 is Geron Corporation.

Stem Cell Transplants

Many of the most respected cancer centers in the United States are using stem cells rather than bone marrow for transplants. According to the Fred Hutchinson Cancer Research Center ( Seattle , WA ), stem cell transplants are substantially more effective for certain high-risk patients, particularly patients with blood borne tumors who are beyond first remission or who have experienced refractory relapse.

In a multicenter trial, 168 patients between the ages of 12-55 with various blood malignancies (leukemia, lymphoma, and myelodysplasia) were randomized to receive either bone marrow or peripheral blood stem cell transplants from HLA-identical sibling donors (Stephenson 2000). The trial was stopped prematurely because a safety monitoring committee determined there was a statistically significant difference in outcome between the two groups. An analysis of 138 of the patients showed that engraftment of platelets and neutrophils was more rapid by about a week in patients who received stem cells. (Engraftment refers to the interval when the donor's marrow cells "attach" to the transplant patient's site and begin to produce healthy cells.) This is momentous because infection looms as a major threat to survival among transplant patients; thus, hastily restoring blood cell production and the efficiency of the immune system is paramount.

Even more impressive were the differences in survival; the 2-year survival rate was 45% among patients with bone marrow transplants compared to 70% among patients with stem cell transplants. The survival advantage was most apparent in patients with more advanced disease. Data were insufficient to determine whether stem cells offer similar advantage over bone marrow for patients with less advanced cancers.

A stem cell transplant involves replacing the diseased marrow with healthy stem cells that match the recipient's. The transplanted stem cells travel through the recipient's blood to the marrow spaces where they begin to grow, producing healthy new blood cells. This occurs after massive amounts of cytotoxic agents have been administered in a courageous attempt to kill the cancer. Unfortunately, the agents that kill cancer cells also kill bone marrow, a spongy tissue in the cavities of large bones that produces blood cells. Without bone marrow, stem cell activity ceases and subsequently so does production of platelets (cells necessary for blood coagulation), white blood cells (cells essential to fight infections and cancer), and red blood cells (cells required for oxygen transport). Without a healthy supply of these vital cells, life expectancy is extremely short.

Not all recipients survive the intensive pretransplant chemotherapy or radiation treatment, which (until recently) were considered the only curative phases of the procedure. Other complications (apart from infections and nonengraftment) include graft-versus-host disease (white blood cells in the marrow fight the patient's body) and relapse (recurrence of the original disease). To find out if you are eligible for this stem cell therapy, contact the Fred Hutchinson Cancer Research Center ( Seattle ) at (800) 804-8824.

Peripheral Blood Stem Cell Transplant Program

The Peripheral Blood Stem Cell Transplant Program allows patients to restore their own supply of blood cells degraded during chemotherapy. Apheresis, a process that withdraws blood and circulates it through a machine, removes the stem cells. Remaining components of the blood are then returned to the patient. The harvested stem cells are stored at a very low temperature, and (after high-dose chemotherapy or radiation therapy) the cells are thawed and returned to the patient through a central venous catheter. Once the stem cells are reinfused into the bloodstream, they return to the bone marrow and begin producing mature red blood cells, white cells, and platelets.

Allogeneic stem cells (donated by another person) are more likely to muster an immune attack against the cancer than autologous stem cells (those harvested from the patient). According to Richard E. Champlin, M.D., chairman of the Department of Blood and Marrow Transplantation at the University of Texas M.D. Anderson Cancer Center, physicians found that allogeneic transplantation harbored unexpected benefits, that is, immunoreactivity against the cancer. In some cases, the graft versus malignancy effect proved curative.

In the past, the threat of graft versus host disease limited the number of patients who were able to undergo allogeneic transplantation but advances in immunosuppressive therapies and cell manipulation techniques have steadily increased the numbers (Wright 2000). Treatment-related mortality rate is about 20% for allogeneic transplants, with the hospital stay about 4 months; autologous transplants have less than a 5% treatment-related mortality and require hospitalization of about 1 month. Transplantation studies are currently being expanded to include ovarian, breast, lung, and renal cell cancers.

For aged and very ill patients, reliance upon high-dose chemotherapy has changed to emphasis upon immune modulation generated by the donor cells. The process, referred to as a minitransplant, allows for a graft versus malignancy effect with the chemotherapeutic drug limited to a low-dose application. A minitransplant can now be performed in senior patients with comorbid conditions, such as hepatitis or cardiac and lung abnormalities. Myeloablative regimens (bone marrow removal) are still used for younger patients and nonablative regimes are used for older or badly compromised patients.

The success rate of transplants varies, but M.D. Anderson Cancer Center reported the results of 13 patients with low-grade lymphoma who underwent a minitransplant: All 13 survived and are in remission. Survival variables include the specific disease, the stage of the disease, and the age and condition of the patient. Typically, the survival rate (measured at 2-3 years) is in the range of 40-60%. The Peripheral Blood Stem Cell Transplant Program is ongoing. Contact the M.D. Anderson Cancer Center information line at (800) 392-1611.

Umbilical Cord Blood Transplants

Umbilical cord blood, a source of cells for transplant, has been life-saving to children who are without an acceptable donor. In about a 4-year time frame, M.D. Anderson Cancer Center has performed 25 umbilical cord blood transplants, all from mismatched donors, on pediatric patients (most with advanced acute leukemia). After a median follow-up of 22 months, 14 of the young patients were alive, and 12 were in remission. (Chalaire 2000). Fatal complications in umbilical cord blood transplants exceed 30% in the first 100 days.

Umbilical cord blood transplants, unlike bone marrow transplants, can tolerate mismatches in HLA (as many as 2-6 antigens), but unfortunately (if the mismatch is large) it increases the time of engraftment (the point when the donor's marrow cells have "attached" to the transplant patient's site and start to produce healthy cells). In addition, umbilical cord blood contains about 10 times fewer cells than bone marrow. The period of engraftment is thus extended to 40-60 days, as compared to 10-20 in bone marrow transplants. During this period of pancytopenia (a marked reduction in the numbers of the formed blood cells), life-threatening infections are a significant threat. Thus, recipients (until recently) have been restricted to children and low-weight adults (Chalaire 2000). A new protocol, that is, combining umbilical cord blood from two or three donors, appears to amend blood cell shortages, making future transplants available to more individuals in diverse age groups.

According to Dr. Champlin, "The important message is that the whole field of blood and marrow transplantation is probably the most dynamic area in all of medicine, where advances in chemotherapy, immunosuppressive agents, genetic therapy, and cellular therapy are all coming together." For more information regarding transplants, contact Dr. Richard E. Champlin at (713) 792-3618 or Dr. Ka Wah Chan at M.D. Anderson Cancer Center (713) 792-7751.

Suppressing Proinflammator Cytokines

There is a growing body of evidence showing that the net biological response of pro- and anti-inflammatory cytokines affects the outcome of several degenerative diseases, including cancer (Dinarello 1997). Cytokines are one of a large group of proteins secreted by various cell types. These relatively small peptides are involved in cell-to-cell communication, coordinating antibody/T-cell immune interactions, and amplifying immune reactivity. The broad family of cytokines includes colony stimulating factors (as G-CSF and GM-CSF), interferons, interleukins, tumor necrosis factor, and macrophage activating and inhibiting factors.

Some cytokines were named for the cellular modulating property with which they were initially associated. For example, tumor necrosis factor has anticancer properties, causing death (necrosis) to certain tumors. But, in inflammatory diseases TNF-alpha (like IL-1) can increase cellular responsiveness to growth factors, inducing signaling pathways that lead to proliferation. In addition, by acting synergistically with epidermal growth factors, TNF-alpha can induce expression of a number of oncogenes, as well as several potentially damaging interleukins (ISU 2001).

Illustrative of TNF-alpha's capriciousness, short-term culture with tumor necrosis factor increases apoptosis (programmed cell death), but extended culture with TNF-alpha suppresses it, probably through induction of IL-8 (Dunican et al. 2000). In vitro , TNF acts as an antiangiogenic; in vivo it assumes the nature of an angiogenic, unless redirected by interferon-gamma, another cytokine (Frater-Schroder et al. 1987).

Tumor necrosis factor (TNF) is secreted by macrophages, monocytes, neutrophils, T-cells, and natural killer cells (following stimulation by bacterial lipopolysaccharides). (Lipopolysaccharide is a major component of the cell wall of Gram-negative bacteria.) Production of TNF (also induced by oxidative stress) can activate nuclear factor-kappaB (NF-kB), a transcription factor. NF-kB, so named because of its cellular location, is normally maintained in an inactive state due to inhibitory molecules. Once activated, NF-kB becomes a potent stimulus to cytokine production. Agents that act at various levels, including antioxidants to repress the production of free radicals, as well as suppressants of TNF and/or NF-kB production, can assist in regulating cytokine production (Martin 2002; Pathfinder Encyclopaedia 2002).

Interleukins (one arm of the cytokine family) are not created equally. Although some show promise in cancer control, that is, IL-2, IL-7, IL-12, IL-15, IL-18, interferon alpha, interferon gamma, GM-CSF, IP-10, and Flt-3 ligand, others can have a deleterious effect. For example, IL-6 attacks the skeletal system and induces telomerase (an enzyme delivering immortality to cancer cells) ( Sotiriou et al. 2001 ); IL-8 inhibits apoptosis and is one of the strongest promoters of inflammation ( Harada 1994 ); IL-10 suppresses NK cell and macrophage function ( Ho et al 1994) ; IL-13 suppresses T-cell mediated immunity and may be involved in the progression of Hodgkin's disease ( de Waal Malefyt et al. 1995; Skinnider et al. 2001) ; IL-4 activates B-cells (promoting their proliferation) while inhibiting the positive effects of IL-2 ( Kay et al 2003) ; IL-9 can increase IL-6 levels ( Cavaillon 1990)

It is important to note that the production of proinflammatory cytokines occurs rapidly following trauma or invasion of the body by disease-causing organisms. But, inflammation is not an efficient means of tumor surveillance. Inflammation, in fact, significantly works against the cancer patient by contributing to weight loss, inhibiting beneficial interleukins, suppressing cell-mediated immunity, and promoting angiogenesis (CIC 2000).

Once an infection or injury stimulates production of IL-1 or TNF-alpha, these two proinflammatory compounds can further stimulate each other, as well as IL-6. In addition, IL-1 and TNF-alpha trigger the production of free radicals, which encourage the production of more proinflammatory cytokines. According to Jack Challem (reporting in Let's Live Magazine), the proinflammatory reaction essentially feeds on itself, setting the stage for chronic inflammation. Although a cytokine response is (at times) essential, excessive production of proinflammatory cytokines or the production of cytokines in the wrong biological context is regarded as poor indicators of stability and even survival among individuals with degenerative disease (Grimble et al. 1998).

Researchers at the University of Colorado Health Sciences Center explain that the cytokine system is self-regulating through the action of anti-inflammatory cytokines, opposing cytokines, and cytokine receptor antagonists. If cytokine regulation becomes deranged (with cytokine numbers favoring those considered inflammatory), the risks of morbidity and mortality markedly increase. Imbalance of proinflammatory and anti-inflammatory cytokines (deregulation) is strongly linked with cardiovascular disease and arthritis and, as the following list indicates, with cancer as well (Arend 2001; Kurzrock 2001).

IL-6 is elevated in the following cancers:

• Brain Tumor: IL-6 appears involved in tumor progression in some glioblastomas, that is, tumors of the cerebrum (the largest and uppermost section of the brain) or spinal cord (Sasaki et al. 2001).
• Breast Cancer: IL-6 levels are nearly 10 times higher in patients with metastatic breast cancer. Elevated IL-6 levels are the most distinguishing factor separating healthy controls from women with breast cancer (Benoy et al. 2002).
• Chronic Lymphocytic Leukemia: Elevations in IL-6 and IL-10 correlate with adverse disease features and short survival in leukemia patients (Fayad et al. 2001).
• Colorectal Cancer: IL-6 is reported to be responsible for loss of lean body mass during cancer cachexia in colon-26 adenocarcinoma (C-26)-bearing mice (Fujita et al. 1996). Data also suggest that carcinoembryonic-secreting tumors (such as colon cancers) induce the production of IL-6 and that IL-6 stimulates tumor cell growth at metastatic sites (Belluco et al. 2000).
• Gynecological Cancers: Higher IL-6 levels are found in women with gynecological cancers, making them less responsive to chemotherapy (Scambia et al. 1996). Consistent elevations in IL-8 and IL-6 are observed in ovarian cancer, the latter proving a negative prognosticator regarding outcome (Penson et al. 2000).
• Lung Cancer: Increased levels of serum IL-6 are found in patients with lung cancer and appear part of a systemic inflammatory response syndrome (Dowlati et al. 1999).
• Lymphoma: Vascular endothelial growth factor (VEGF), an angiogenesis promoter, and IL-6 levels are often higher in patients with aggressive lymphoma. Disease-free survival rates for patients displaying high levels of VEGF or IL-6 are poor, but the prognosis becomes worse if VEGF/IL-6 elevations coexist (Niitsu et al. 2002).
• Multiple Myeloma: IL-6 is an important cytokine in myeloma cell growth and proliferation. Close cell-to-cell contact between myeloma cells and the bone marrow stromal cells triggers a large amount of IL-6 production, which supports the growth of malignant cells, as well as protecting them from apoptosis. Elevations in IL-6 are deemed (by some) highly predictive of survival (Blade et al. 2002; Hussein et al. 2002).
• Obstructive Jaundice: Elevations in TNF-alpha and IL-6 are observed in patients with malignant obstructive jaundice, especially those with a poor immediate prognosis (Puntis et al. 1996).
• Pancreatic Cancer: IL-6 and IL-8 play a role in several pancreatic diseases, including pancreatic cancer (Blanchard et al. 2001).
• Prostate Cancer: Prostate cancer cells produce factors that increase IL-6, a known activator of bone resorption (Garcia-Moreno et al. 2002).
• Renal Cell Carcinoma: IL-6 is implicated in osteoclastic bone resorption and hypercalcemia, factors associated with metastatic renal cell cancer (Paule 2001).

Important information was released in 2002 regarding the impact of too little sleep upon IL-6 production. Researchers found that getting adequate sleep lessened IL-6 production and exposure of tissues to its potentially detrimental actions. Sleep deprivation caused a 40-50% average increase in IL-6 (in both men and women) and a 20-30% increase in tumor necrosis factor in men. Dr. Alexandros Vgontzas (professor of psychiatry at Pennsylvania State University) stated at the annual meeting of the Endocrine Society (June 22, 2002) that 8 hours of sleep is not a nice bonus but a necessity if one is concerned with good health. Considering the risks imposed by over-expression of proinflammatory cytokines, every precaution should be implemented to preserve equilibrium between pro- and anti-inflammatory cytokines. Thus, if insomnia is a problem, please consult the Insomnia protocol for assistance in overcoming this disorder (Vgontzas et al. 1999; 2001).

Therapies that influence the tumor and its microenvironment are being aggressively pursued with the goal of converting active malignancies to chronic disease states, with the patient maintaining a normal lifestyle (Hussein et al. 2002). Much of current research, thus, focuses upon modulation of the family of proinflammatory cytokines with anti-inflammatory drugs, cytokine receptor antagonists, and nutrients (Di Girolamo et al. 1997; Grimble et al. 1998).

There are natural agents and prescription drugs that suppress proinflammatory cytokines. Many nutrients are broad-spectrum cytokine inhibitors, meaning they are capable of inhibiting several proinflammatory cytokines. Although relying upon a single nutrient (as a cytokine inhibitor) is not recommended, it is not necessary to incorporate the full list of inhibitors into a therapeutic program.

The following list comprises dietary supplements that suppress inflammatory cytokines:

• DHEA inhibits TNF-alpha by 98% and IL-6 by 95% (Kipper-Galperin et al. 1999).
• Alpha Tocopherol (Vitamin E) significantly lowered levels of C-reactive protein and IL-6 at a dosage of 1200 IU a day (Devaraj et al. 2000).
• DHA and EPA may reign supreme as an inhibitor of dangerous cytokines. IL-6 is potentiated when endothelial cells are stimulated. Omega-3 fatty acids restrain stimulating factors, such as TNF-alpha, IL-4, or lipopolysaccharides. Void of stimulation, endothelial cells are inhibited in their production of IL-6 (Khalfoun et al. 1997). Fish oil inhibited IL-1 and TNF-alpha by =90% (James et al. 2000). It should also be noted that psychological stress induces the production of proinflammatory cytokines, such as TNF-alpha, IL-6, and IL-10. Increasing omega-3 PUFAs lessened the proinflammatory response to psychological stress (Maes et al. 2000). DHA and EPA can be obtained directly from fish oil concentrates or indirectly from perilla or flax oils.
• N-Acetylcysteine (NAC) inhibited the production of IL-6 and IL-8 induced by TNF-alpha or lipopolysaccharides (Munoz et al. 1996; Gosset et al. 1999).
• Vitamin K inhibited IL-6 production by lipopolysaccharide-stimulated human fibroblasts. Fibroblasts are recognized as rich sources of cyto-kines (Reddi et al. 1995).

The transcription factor (NF-kappaB) is implicated in several types of malignancies. Once activated, NF-kB is responsible for an onslaught of proinflammatory cytokines. Generally, suppression of NF-kB correlates well with inhibition of various damaging cytokines, including IL-6 and IL-8. NF-kB can be inhibited by:

• Alpha-Lipoic Acid, antioxidants that eliminate reactive oxygen species, also block NF-kB. Lipoic acid is particularly effective, completely inhibiting NF-kB at a fifth of the dosage required by N-acetyl-cysteine (Suzuki et al. 1992).
• Alpha Tocopherol Succinate (Vitamin E) prevents monocytic cell adhesion to cytokine-stimulated endothelial cells by inhibiting the activation of NF-kappa B (Erl et al. 1997).
• Curcumin blocks NF-kB activation and a generation of proinflammatory cytokines (Jobin et al. 1999).
• Feverfew contains a lactone or chemical compound called parthenolide according to Newmark et al. (2000).
• Researchers at Children's Hospital Medical Center ( Cincinnati , OH ) determined that parthenolide inhibits nuclear factor-kB activity (Sheehan et al. 2002).
• Genistein, an isoflavone in soy, inhibits both basic and inducible NF-kB activation (Tabary et al. 1999).
• Green Tea, the EGCG fraction, displays a potent inhibitory effect on NF-kB expression in hypoxic cells (Yang et al. 1998; Muraoka et al. 2002).
• Quercetin has the ability to inhibit NF-kB and inflammatory mediators produced by it (Ishikawa et al. 1999).
• Silymarin, a bioflavonoid, potently suppresses NF-kB, a key in inflammatory and immune reactions (Saliou et al. 1998).
• Stinging Nettle (standardized plant extracts from the leaves of stinging nettle, IDS23) reliably inhibits NF-kB (Riehemann et al. 1999).
• Vitamin C inhibits the activation of NF-kB by multiple stimuli, including IL-1 and TNF-alpha (Bowie et al. 2000).

Note: For specific information about the nutrients detailed in the list, refer to the Cancer Adjuvant Therapy protocol.

Comments on These Findings

The fact that many antioxidants are strong inhibitors of NF-kB activation appears to explain another of the pathways antioxidants utilize to defend against cancer. Various chemotherapeutic agents increase expression of both good and bad cytokines. Thus, questions regarding safe usage of natural agents that elicit production of both pro- and anti-inflammatory cytokines arise.

Most of our knowledge regarding proinflammatory cytokines (such as IL-1 or TNF-alpha) is derived from experiments in which humans or animals have been injected with either a single or a combination of inflammatory cytokines (Dinarello 1997). However, in models of inflammation where several cytokines are produced, specific blockade of either IL-1 or TNF-alpha (or both) results in a reduction in the severity of inflammation. This may explain the success when using agents that lift expression of many of the family of cytokines, both pro- and anti-inflammatory in nature.

It is possible to test one's blood level of proinflammatory cytokines such as TNF-alpha, interkeukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1(b). For information regarding cytokine blood testing, call (800) 208-3444.

Although there are many supplements that can suppress proinflammatory cytokines and inhibit the expression of NF-kB, the following are the ones most commonly used by cancer patients:

Fish oil: 1300 mg DHA and 500 mg EPA a day to suppress inflammatory cytokines. (Note: This potency of DHA and EPA can be obtained by taking 8 capsules a day of a product called Super GLA/DHA.)

• DHEA: 15-75 mg a day to suppress inflammatory cytokines. Refer to DHEA Replacement Therapy protocol for precautions.
• Curcumin (with Bioperine): 3600 mg a day to mitigate NF-kB activation and to inhibit protein kinase C. (Note: This potency can be obtained by taking four capsules of Super Curcumin with Bioperine once a day with a heavy meal containing fat.)
• Green Tea Extract (95%): 1500 mg 3 times a day to mitigate NF-kB activation and to inhibit the telomerase enzyme. (Note: This potency can be obtained by taking 5 Super Green Tea Extract capsules 3 times a day.)
• Genistein: 2700 mg a day to inhibit protein kinase C and to mitigate NF-kB activation. (Note: This potency can be obtained by taking 5 Ultra Soy Extract capsules 4 times a day.)
• Tocopheryl Succinate (dry vitamin E): 400-1200 IU a day to mitigate NF-kB activation and to inhibit protein kinase C.

SUMMARY

The cancer patient has a wide range of treatment choices to inhibit molecular mechanisms that cancer cells utilize for survival and propagation. It is interesting to note that nutrients such as green tea extract, curcumin, and tocopheryl succinate function in several different ways to inhibit tumor cell proliferation.

For a more thorough description of how certain dietary supplements may be of benefit to the cancer patient, refer to the Cancer Adjuvant Therapy protocol .

Note: Data were collected (in part) from the work of Dr. Frank McCormick, chief scientific officer at Onyx Pharmaceuticals, and Dr. Allen Oliff, executive director for cancer research, and Dr. Jackson Gibbs, senior director of cancer results, both at Merck Research Laboratories.

Product availability

Super GLA/DHA, Mega EPA, tocopheryl succinate capsules (vitamin E), vitamin C, alpha-lipoic acid, quercetin, DHEA, Ultra Soy, Super Curcumin w/Bioperine, Super Green Tea Extract, silymarin , and Silibinin Plus can be ordered by calling (800) 544-4440 or by ordering online at www.lef.org.

Staying Informed

The information published in this protocol is only as current as the day the manuscript was sent to the printer. This protocol raises many issues that are subject to change as new data emerge. Furthermore, cancer is still a disease with unacceptably high mortality rates, and none of our suggested regimens can guarantee a cure.

The Life Extension Foundation is constantly uncovering information to provide to cancer patients. A special website has been established for the purpose of updating patients on new findings that directly pertain to the published cancer protocols. Whenever Life Extension discovers information that may benefit cancer patients it will be posted on the website www.lefcancer.org.

Before utilizing the cancer protocols in this book, we suggest that you check www.lefcancer.org to see if any substantive changes have been made to the recommendations described in this protocol. Based on the sheer number of newly published findings, there could be significant alterations to the information you have just read.

Alternatively, call 1-800-226-2370 and ask a Health Advisor if your topic of interest has been updated on the website - www.lefcancer.org.