Inhibition and Regression of Experimental Oral Cancer by Beta Carotene and Vitamin E: Emerging Concepts

  • Gerald Shklar
Part of the Experimental Biology and Medicine book series (EBAM, volume 27)

Abstract

The hamster buccal pouch experimental model for oral cancer has proven to be a superior model for oral mucosal carcinogenesis and is now receiving wide attention as one of the better overall experimental models for carcinogenesis. The malignant tumors are epidermoid carcinomas that develop slowly, in response to polyaromatic hydrocarbon carcinogen application, and are preceded by a keratotic and dysplastic lesion comparable to human precancerous leukoplakia. The hamster lesions are indistinguishable histologically from human oral epidermoid carcinomas of the well-to-moderately differentiated variety, at both light microscopic and ultrastructural levels. Both animal and human lesions have similar metabolic markers, such asgamma glutamyl transpeptidase (GGT) and lactic dehydrogenase. The hamster carcinoma develops with the activation and expression of specific oncogenes, often similar to those expressed in human oral cancer. These include c-erbBl, H-ras, K-ras, and mutant p53. The hamster lesions are clearly visible at all times and can be counted and measured at different stages of development so that figures can be obtained for overall tumor burden. The hamster tumors are also closely related to immune control, as in humans. The hamster tumor development is enhanced by immunosuppressive drugs such as cortisone and methotrexate, and retarded by immunoenhancing agents such as levamisole or BCG.

In the quest for chemopreventative agents, it was foundthat hamster oral carcinogenesis could be retarded by retinoids such as 13-cis-retinoic acid. However, retinoids were found to be toxic and to have a co-carcinogenic potential. Beta carotene and vitamin E were found to be nontoxic and inhibited oral carcinogenesis when applied topically, injected in the tumor area, or administered systemically by mouth. Regression of established carcinomas was also possible when beta carotene or vitamin E was injected into the tumor site. Mixtures of beta carotene and vitamin E were found more effective antitumor agents than the individual substances, indicating a synergism. Mixtures of various antioxidants have been studied and found to be highly effective. Current research is aimed at an understanding of mechanism. These studies use both hamster tumors and cell lines in culture from both hamster carcinomas and human oral carcinomas. A concept has been established of a common pathway for the destruction of cancer cells. Beta carotene, vitamin E, and other antioxidants act as immunostimulators in one branch of the pathway. They stimulate the migration to tumor site and the antitumor activity of cytotoxic macrophages, bearing TNF-alpha, and cytotoxic T lymphocytes, bearing TNF-beta. In the other branch of the common pathway, the antioxidant nutrients stimulate enhanced expression of a variety of proteins, including 70 and 90 kD stress proteins. There is also a dramatic reduction in mutant p53 and an increased expression of the wild type (antioncogene) p53 protein product. The antioxidant nutrients appear to enhance the tumor suppressor p53 gene and to dysregulate or inactivate the mutant p53 oncogene. The cancer cells are selectively destroyed in a process described as apoptosis. The antioxidants also inhibit angiogenesis, which would also contribute to the death of cancer cells. Many clinical applications can be suggested, based on this animal research.

Keywords

Glutathione Selenium Bacillus Methotrexate Carotenoid 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Gimenez-Conti, I. B.,and Slaga, T.J.The hamster cheek pouch carcinogenesis model. J. Cellular Biochem., 17F: 83–90, 1993.CrossRefGoogle Scholar
  2. 2.
    Salley, J. J. Experimental carcinogenesis in the cheek pouch of the Syrian hamster. J. Dent. Res., 33: 253–258, 1954.CrossRefGoogle Scholar
  3. 3.
    Morris, A. L. Factors influencing experimental carcinogenesis in the hamster cheek pouch. J. Dent. Res., 40: 3–10, 1961.CrossRefGoogle Scholar
  4. 4.
    Silberman, S., and Shklar, G. The effect of a carcinogen (DMBA) applied to the hamster’s buccal pouch in combination with croton oil. Oral Surg., 16: 1344–1355, 1963.CrossRefGoogle Scholar
  5. 5.
    ShklarG.Experimental oral pathology in the Syrian hamster. Prog. Exp. Tumor Res., 16: 518–538, 1972.Google Scholar
  6. 6.
    Santis, H., Shklar, G., and Chauncey, H. The histochemistry of experimentally induced leukoplakia and carcinoma of the hamster buccal pouch. Oral Surg., 17: 207–218, 1964.CrossRefGoogle Scholar
  7. 7.
    Shklar, G. Oral leukoplakia. N.E.J. Med., 315: 1544–1546, 1986.CrossRefGoogle Scholar
  8. 8.
    Weerapradist, W., and Shklar, G. Vitamin E inhibition of hamster buccal pouch carcinogenesis. A gross, histologic and ultrastructural study. Oral Surg., 54: 304–312, 1982.CrossRefGoogle Scholar
  9. 9.
    Shklar, G., Eisenberg, E., and Flynn, E. Immunoenhancing agents and experimental leukoplakia and carcinoma of the hamster model pouch. Prog. Exp. Tumor Res., 24: 269–282, 1979.Google Scholar
  10. 10.
    Solt, D. B. Localization of gamma-glutamyl-transpeptidase in hamster buccal pouch epithelium treated with 7,12 dimethylbenz(a)anthracene. J. Natl. Cancer Inst., 67: 193–200, 1981.Google Scholar
  11. 11.
    Solt, D. B., and Shklar, G. Rapid induction of gammaglutamyl transpeptidase-rich intraepithelial clones in 7,12-dimethylbenz(a)-anthracene treated hamster buccal pouch. cancer Res., 42: 285–291, 1982.Google Scholar
  12. 12.
    Shklar, G. Lactic dehydrogenase activity in cytologic smears of normal oral mucosa and epidermoid carcinoma, Acta. Cytol., 9: 437–439, 1965.Google Scholar
  13. 13.
    Shklar, G. Metabolic characteristics of experimental hamster pouch carcinomas. Oral Surg., 20: 336–339, 1965.CrossRefGoogle Scholar
  14. 14.
    Lindberg, K., and Rheinwald, J. G. Suprabasal 40 Kd keratin expression as an immunohistological marker of premalignancy in oral epithelium. Am. J. Path., 134: 89–98, 1989.Google Scholar
  15. 15.
    Niukian, K., Schwartz, J., and Shklar, G. Effects of Onion extract on the development of hamster buccal pouch carcinogenesis as expressed in tumor burden. Nutr. Cancer, 9: 171–176, 1987.CrossRefGoogle Scholar
  16. 16.
    Woods, D. A. Influence of antilymphocyte serum on DMBA induction of oral carcinomas. Nature, 224: 276–279, 1969.CrossRefGoogle Scholar
  17. 17.
    Shklar, G. cortisone and hamster buccal pouch carcinogenesis. Cancer Res., 26: 246–263, 1966.Google Scholar
  18. 18.
    Shklar, G., Cataldo, E., and Fitzgerald, A. The effect of methotrexate on chemical carcinogenesis of hamster buccal pouch. Cancer Res., 26: 2218–2224, 1966.Google Scholar
  19. 19.
    Giunta, J., and Shklar, G. The effect of antilymphocyte serum on experimental hamster buccal pouch carcinogenesis. Oral Surg., 31: 344–355, 1971.CrossRefGoogle Scholar
  20. 20.
    Giunta, J., Reif, A. E., and Shklar, G. Bacillus Calmette-Guerin and antilymphocyte serum in carcinogenesis. Arch. Pathol., 98: 237–240, 1974.Google Scholar
  21. 21.
    Eisenberg, E., and Shklar, G. Levamisole and hamster buccal pouch carcinogenesis. Oral Surg., 43: 562–574, 1977.CrossRefGoogle Scholar
  22. 22.
    Wong, D. T. W., and Biswas, D. K. Activation of c-erb B oncogene in the hamster cheek pouch during DMBA- induced carcinogenesis. Oncogene, 2: 67–72, 1987.Google Scholar
  23. 23.
    Merlino, G. T., Xu, H. Y., Ishii, S., et al: Elevated epidermal growth factor receptor gene copy number and expression in a squamous carcinoma cell line. Science, 224: 417–491, 1974.CrossRefGoogle Scholar
  24. 24.
    Husain, Z., Fei, Y., Roy, S., Solt, D. B., Polverini, P. J., and Biswas, D. K. Sequential expression and cooperative interaction of c-Ha-ras and c-erb B genes in in vivo chemical carcinogenesis. Proc. Natl. Acad. Sci. USA., 86: 1264–1268, 1989.CrossRefGoogle Scholar
  25. 25.
    Gimenez-Conti, I. B., Bianchi, A. B., Stockman, S. L., Conti, C. J., and Slaga,T.J. Activating mutation of the Ha-ras gene in chemically induced tumors of the hamster buccal pouch. Mol. Carcinogenesis, 5: 259–263, 1992.CrossRefGoogle Scholar
  26. 26.
    Wong, D. T. W., Gertz, R., Chow, P., et al: Detection of Ki-ras mRNA in normal and chemically transformed hamster oral keratinocytes. Cancer Res., 49: 4562–4567, 1989.Google Scholar
  27. 27.
    Odukoya, O., Shklar, G. Initiation and promotion in experimental oral carcinogenesis. Oral Surg., 58: 315–323, 1984.CrossRefGoogle Scholar
  28. 28.
    Silberman, S., and Shklar, G. The effect of a carcinogen (DMBA) applied to the hamster buccal pouch in combination with croton oil. Oral Surg., 16: 1344–1360, 1963.CrossRefGoogle Scholar
  29. 29.
    Freedman, A., and Shklar, G. Alcohol and hamster buccal pouch carcinogenesis. Oral Surg., 46: 794–810, 1978.CrossRefGoogle Scholar
  30. 30.
    Oh, J. S., Paik, D., Christensen, R., Akoto-Amanfo, E., Kim, K., and Park, N-H. Herpes simplex virus enhances the 7,12-dimethylbenz(a)anthracene (DMBA) induced carcinogenesis and amplification and over expression of c-erb-B1 proto-oncogene in hamster buccal pouch. Oral Surg., 68: 428–435, 1989.CrossRefGoogle Scholar
  31. 31.
    Okukoya, O., Schwartz, J., Weichselbaum, R., and Shklar, G. An epidermoid carcinoma cell line derived from hamster 7,12 dimethylbenz(a)anthracene induced buccal pouch tumors. J. Natl. Cancer Inst., 71: 12531264, 1983.Google Scholar
  32. 32.
    Sporn, M. B., Dunlop, N. M., Newton, D. L., and Smith, J. M. Prevention of chemical carcinogenesis by vitamin A and its synthetic analogs (retinoids). Fed. Proc., 35: 1332–1338, 1976.Google Scholar
  33. 33.
    Shklar, G., Schwartz, J., Grau, D., Trickler, D. P., and Wallace, D. K. Inhibition of hamster buccal pouch carcinogenesis by 13-cis retinoic acid. Oral Surg., 50: 45–53, 1980.CrossRefGoogle Scholar
  34. 34.
    Burge-Bottenbley, A., and Shklar, G. Retardation of experimental oral cancer development by retinyl acetate. Nutr. Cancer., 5: 121–129, 1983.CrossRefGoogle Scholar
  35. 35.
    Shklar, G. Inhibition of oral mucosal carcinogenesis by vitamin E. J. Natl. Cancer Inst., 68: 791–797, 1982.Google Scholar
  36. 36.
    Trickler, D., Shklar, G. Prevention by vitamin E of oral carcinogenesis. J. Natl, Cancer Inst., 78: 165–169, 1987.Google Scholar
  37. 37.
    Suda, D., Schwartz, J., Shklar, G. Inhibition of experimental oral carcinogenesis by topical beta carotene. Carcinogenesis., 7: 711–715, 1986.CrossRefGoogle Scholar
  38. 38.
    Schwartz, J., Suda, D., Light, G. Beta carotene is associated with the regression of hamster buccal pouch carcinoma and the induction of tumor necrosis factor in macrophages. Biochem. Biophys. Res. Commun., 136: 1130–1135, 1986.Google Scholar
  39. 39.
    Schwartz, J., Shklar, G. Regression of experimental oral carcinoma by local injection of beta carotene and canthaxanthin. Nutr. Cancer., 11: 35–40, 1988.Google Scholar
  40. 40.
    Shklar, G., Schwartz, J., Trickler, D. P., Niukian, K. Regression by vitamin E of experimental oral cancer. J. Natl. Cancer Inst., 78: 987–992, 1987.Google Scholar
  41. 41.
    Shklar, G., Schwartz, J., Trickier, D., and Reid, S. Regression of experimental cancer by oral administration of combined alpha tocopherol and beta carotene. Nutr. Cancer., 12: 321–325, 1989.Google Scholar
  42. 42.
    Trickier, D., Shklar, G., and Schwartz, J. Inhibition of oral carcinogenesis by glutathione. Nutr. Cancer., 20: 139–144, 1993.CrossRefGoogle Scholar
  43. 43.
    Shklar, G., Schwartz, J., Trickier, D., and ReidCheverie, S. The effectiveness of a mixture of beta carotene, alpha tocopherol, glutathione and ascorbic acid for cancer chemoprevention. Nutr. Cancer., 20: 145–151, 1993.Google Scholar
  44. 44.
    Shklar, G., and Schwartz, J. L. A common pathway for the destruction of cancer cells: experimental evidence and clinical implications. Int. J. Oncol., 41: 215–224, 1994.Google Scholar
  45. 45.
    Shklar, G., Schwartz, J. L. Tumor necrosis factor in experimental cancer regression with alpha tocopherol, beta carotene and alga extract. Eur. J. Cancer Clin. Oncol., 24: 839–850, 1988.CrossRefGoogle Scholar
  46. 46.
    Shklar, G., Schwartz, J. L., Trickier, D. P., and Reid, S. Prevention of experimental cancer and immunostimulation by vitamin E (Immunosurveillance). J. Oral Pathol. Med., 19: 60–64, 1990.CrossRefGoogle Scholar
  47. 47.
    Flynn, E. A., Schwartz, J. L., and Shklar, G. Sequential mast cell infiltration and degranulation during experimental carcinogenesis. J. Cancer Res. Clin. Oncol., 117: 115–122, 1991.CrossRefGoogle Scholar
  48. 48.
    Wong, D. T. W. TGF-alpha and oral carcinogenesis. Oral Oncol. Eur. J. Cancer., 29B: 3–7, 1993.CrossRefGoogle Scholar
  49. 49.
    Schwartz, J. L., Antoniades, D. Z., and Zhao, S. Molecular and biochemical reprogramming of oncogenesis through the activity of prooxidants or antioxidants. Ann. N.Y. Acad. Sc., 478,1993.Google Scholar
  50. 50.
    Schwartz, J. L., Shklar, G., and Trickier, D. P. p53 in the anticancer mechanism of vitamin E. Oral Oncol. Eur. J. Cancer., 29B: 313–318, 1993.CrossRefGoogle Scholar
  51. 51.
    Trickier, D. P., West, K., Shklar, G., and Schwartz, J. L. Mutant p 53 decrease during glutathione inhibition of oral carcinogenesis. J. Dent. Res., 73: 264, 1944.Google Scholar
  52. 52.
    Schwartz, J. L. Beta carotene induced programmed cell death. J. Dent. Res., 72: 283, 1993.Google Scholar
  53. 53.
    Folkman, J. What is the evidence that tumors are angiogenesis dependent? J. Nat. Cancer Inst., 82: 4–6, 1990.CrossRefGoogle Scholar
  54. 54.
    Menkes, M. S., Comstock, G. W., Vuilleumier, J. P., et al: Serum beta carotene, vitamins A and E, selenium and the risk of lung cancer. N. Engl. J. Med., 315: 1250–1254, 1986.CrossRefGoogle Scholar
  55. 55.
    Palan, P. R., Mikhail, M. S., Basu, J., and Romney, S. L. Plasma levels of antioxidant beta carotene and tocopherol in uterine cervix dysplasia and cancer. Nutr. Cancer., 15: 13–20, 1991.Google Scholar
  56. 56.
    Hong, W. K., Endicott, J., Itri, L. M. et al: 13-cis retinoic acid in the treatment of oral leukoplakia. N. Engl. J. Med., 315: 1501–1510, 1986.CrossRefGoogle Scholar
  57. 57.
    Brenner, S. E., Winn, R. J., Lippman, S. M., Poland, J., Hansen, K. S. et al: Regression of oral leukoplakia with tocopherol: A community clinical oncology pro-gram. Chemopreventative study. J. Natl. Cancer Inst., 85: 44–48, 1993.CrossRefGoogle Scholar
  58. 58.
    Garewal, H. S., Meyskens, F. L., Killen, D., et al: Response of oral leukoplakia to beta carotene. J. Clin. Oncol., 8: 1711–1720, 1990.Google Scholar
  59. 59.
    Schwartz, J., and Shklar, G. The selective cytotoxic effect of carotenoids and tocopherol on human cancer cell lines in vitro. J. Oral Maxillofac. Surg., 50: 367–373, 1992.CrossRefGoogle Scholar
  60. 60.
    Schwartz, J. L., Tanaka, V., Khandekar, V., Herman, T. S., and Teicher, B. A. Beta carotene and/or vitamin E as modulators of alkylating agents in SCC-25 human squamous carcinoma cells. Cancer Chemother. Pharmacol., 29: 207–214, 1992.Google Scholar

Copyright information

© Springer Science+Business Media New York 1995

Authors and Affiliations

  • Gerald Shklar
    • 1
  1. 1.Harvard School of Dental MedicineBostonUSA

Personalised recommendations