Lymphoid cancers

Vincamine, vinblastine and vincristine are very important clinic alkaloids. They are produced naturally by plants vincamine by Vinca minor, and vinblascine and vincristine by Madagascar periwinkle Catharanthus roseus). The vindoline synthesis pathway starts with strictosidine and, via dehydrogeissoschizine, preakuammicine, stemmadenine and tabersonine, is converted to vindoline and vincristine (Figure 42). Conversion from vindoline to vinblastine is based on the NADH enzyme activity. Vinblastine and vincristine are very similar alkaloids. The difference is that vincristine has CHO connected to N, whereas vinblastine in the same situation has only CO3. This synthetic structural differences influence their activity. Vinblastine is used to treat Hodgkin s disease (a form of lymphoid cancer), while vincristine is used clinically in the treatment of children s leukaemia. Vincristine is more neurotoxic than vinblastine. 

Nemunaitis J, Rabinowe SN, Singer JW et al. (1991). Recombinant granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for lymphoid cancer. New Eng J Med, 324, 1773-1778. 

Frezza, E.E., Fung, J., and van Thiel, D.H., Non-lymphoid cancer after liver transplantation, Hepatogastro-enterology, 44(16), 1172-1181, 1997. 

Bandres et al. examined the expression of 156 mature miRNA in colorectal cancer by real-time PCR and the results suggested that miRNA expression profile could be relevant to the biological and clinical behavior of colorectal neoplasia [58]. Michael et al. identified 28 different miRNAs in a colonic adenocarcinoma and normal mucosa by using miRNA cloning and northern blotting. They also indicated that miR-143 and miR-145 are downregulated in cells derived from breast, prostate, cervical, and lymphoid cancers as well as colorectal tumors [59]. 

Mammalian Cells Unlike microbial cells, mammalian cells do not continue to reproduce forever. Cancerous cells have lost this natural timing that leads to death after a few dozen generations and continue to multiply indefinitely. Hybridoma cells from the fusion of two mammalian lymphoid cells, one cancerous and the other normal, are important for mammalian cell culture. They produce monoclonal antibodies for research, for affinity methods for biological separations, and for analyses used in the diagnosis and treatment of some diseases. However, the frequency of fusion is low. If the unfused cells are not killed, the myelomas 1 overgrow the hybrid cells. The myelomas can be isolated when there is a defect in their production of enzymes involved in nucleotide synthesis. Mammahan cells can produce the necessary enzymes and thus so can the fused cells. When the cells are placed in a medium in which the enzymes are necessaiy for survival, the myelomas will not survive. The unfused normal cells will die because of their limited life span. Thus, after a period of time, the hybridomas will be the only cells left ahve. 

PERRIN F, PERRIN P, CHAMP M, BORNE, F, MEFLAH K, MENANTEAU J (1997) Short-chain frUCtO-oligosaccharides rednce the occurrence of colon tumor and develop gut-associated lymphoid tissue in Min mice. Cancer Res. 57 225-8. 

The malignant lymphomas are hematologic cancers that consist of a cluster of diseases of the lymphoid tissue. The primary malignant cells for lymphomas are lymphocytes of B-cell, T-cell, and NK-cell origin. These cells originate from a small population of... 

Yu, H.-S. et al., Alterations of skin-associated tissue lymphoid tissue in the carcinogenesis of arsenical skin cancer, Proc. Natl. Sci. Counc. Repub. China B, 16, 17, 1992. 

Hormonal drags do not cure cancer, although they do exhibit pronounced palliative action, with the exception of the cytotoxic action of glucocorticoids on lymphoid cells. In particular, this concerns predinsone, which is used to treat lymphomas and certain leukemias in combination therapy. 

MM = multiple myeloma ATL = adult T-cell leukemia ALL = acute lymphoblastic leukemia CLL = chronic lymphocytic leukemia FCC = follicular center cell lymphoma DLC = diffuse large cell lymphoma TRB = T-cell rich B-cell lymphoma ALCL = anaplastic large cell lymphoma MALT = mucosa-associated lymphoid tissue-type lymphoma LC = lung cancer CMM = cutaneous malignant melanoma TCC = transitional cell carcinoma CSCC = cutaneous squamous cell carcinoma. 

Kaplan, H.S. and Brown, M.B. (1952). A quantitative dose response study of lymphoid-tumor development in irradiated C57 black mice, J. Natl Cancer Inst. 13,185. 

Whelan JS, Davis CL, Rule S, Ransom M, Smith OP, Metha AB, Catovsky D, Rohatiner AZ, Lister . Fludarabine phosphate for the treatment of low grade lymphoid malignancy. Br J Cancer 1991 64 120-123. 

Martin, M.S., Hammann, A. Martin, F. (1986) Gut-associated lymphoid tissue and 1,2-dimethylhydrazine intestinal tumors in the rat a histological and immunoenzymatic study. Int. J. Cancer, 38, 75-80... 

Nauss, K.M., Locniskar. M., Pavlina, T. Newbeme, PM. (1984) Morphology and distribution of 1,2-dimethylhydrazine dihydrochloride-induced colon tumors and their relationship to gut-associated lymphoid tissue in the rat. J. natl Cancer Inst., 73, 915-924... 

An additional line of defense is provided by natural killer cells (NK cells), a type of circulating lymphoid cell able to kill cancer cells, to participate in antiviral defenses, and to help control immune responses.273 -276 NK cells, which utilize their own signaling pathways, are also able to use MHC class I molecules to recognize and to spare the lives of normal, healthy cells.277/277a b Partial deprivation of a night s sleep can reduce NK cell activity, damaging the cellular immune response.278... 

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