Epithelial cell tumors

ABC-B (11) photoreceptor proteins Efflux transporters, multiple drug MDR, TAP, Epithelial cells, tumor cells... 

A factor known as scatter factor has been characterized which causes the break up and stimulates motility of epithelial cell clumps (Stoker et al., 1987). This factor is identical to hepatocyte growth factor and increases the rate of locomotion of several other cell types. Motility factors elaborated from tumor cells are considered to play an important role in metastasis (see later). Guidance of cells by the physical topography of the substratum is another factor that profoundly affects the behavior of cells. 

IFNs are natural glycoproteins produced by the cells of most vertebrates in response to the challenge by foreign agents, such as infectious organisms (viruses, bacteria, fungi, and parasites), and by tumor cells. IFNs can be produced by cells of the innate and adaptive immune systems and by non-immune cells such as fibroblasts and epithelial cells. 

Lemercier, J.-N. Meier, B. Gomez, J. D. Thompson, J. A. Inhibition of glutathione S-transferase Pl-1 in mouse lung epithelial cells by the tumor promoted 2,6,di-tert-butyl-4-methylene-2,5-cylcohexadienone (BHT-quinone methide) protein adducts investigated by electrospray mass spectrometry. Chem. Res. Toxicol. 2004, 17, 1675-1683. 

Sun, Y. Dwyer-Nield, L. D. Malkinson, A. M. Zhang, Y. L. Thompson,J. A. Responses of tumorigenic and non-tumorigenic mouse lung epithelial cell lines to electrophilic metabolites ofthe tumor promoter butylated hydroxytoluene. Chem.-Biol. Interact. 2003, 145, 41-51. 

Epithelial ovarian tumors are composed of cells that cover the surface of the ovary, such as serous, mucinous, endometrioid, clear cell, and poorly differentiated adenocarcinomas. 

Cholesteatoma A mass of keratinized epithelial cells and cholesterol resembling a tumor that forms in the middle ear or mastoid region. 

Interleukin-6 (IL-6) is a small polypeptide with a molecular mass of 26 kDa (see Table 2). IL-6 can be induced in various cell types, including fibroblasts, macrophages/monocytes, epithelial cells, T cells, B cells, and diverse tumor cells (L4). TNF, IL-1, and LPS can stimulate IL-6 gene expression in macrophages/monocytes and fibroblasts. In vivo studies showed that systemic administration of TNF, LPS, and IL-1 was followed by a rapid induction of circulating IL-6 (B49, J2). Also, endothelin (ET) at concentrations observed pathophysiolog-ically may trigger production of IL-6 (Ml7). 

P-glycoprotein is not only expressed in tumor cells, but also in cells of several healthy tissues. In liver it was detected in the biliary canalicular surface of hepato-cytes and the apical surface of small biliary ductules. In the small intestine and colon, it is localized in the apical surface of columnar epithelial cells, and in kidneys it is found in the brush border membrane of proximal tubules. Moreover, it is detectable on the apical surface of small ductules in the pancreas and on the surface of cells in the medulla and cortex of adrenals [2]. 

Colquhoun and Schumacher [98] have shown that y-linolcnic acid and eicosapentaenoic acid, which inhibit Walker tumor growth in vivo, decreased proliferation and apoptotic index in these cells. Development of apoptosis was characterized by the enhancement of the formation of reactive oxygen species and products of lipid peroxidation and was accompanied by a decrease in the activities of mitochondrial complexes I, III, and IV, and the release of cytochrome c and caspase 3-like activation of DNA fragmentation. Earlier, a similar apoptotic mechanism of antitumor activity has been shown for the flavonoid quercetin [99], Kamp et al. [100] suggested that the asbestos-induced apoptosis in alveolar epithelial cells was mediated by iron-derived oxygen species, although authors did not hypothesize about the nature of these species (hydroxyl radicals, hydrogen peroxide, or iron complexes ). 

Lung cancer is a solid tumor originating from bronchial epithelial cells. This chapter distinguishes between non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) because they have different natural histories and responses to therapy. 

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