Apoptotic indexes

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 ). 

Although individual nuclear fragments of the late apoptotic cells are within the same cell they may be completely separated from each other. Therefore, they may be separately contoured and each fragment identified as a whole individual nucleus of an apoptotic cell with a fractional (sub-G,) DNA content. This may lead to an overestimate of a frequency of apoptotic cells (apoptotic index). 

A further consideration that is very important in whole animal studies is the inter-individual variation in response to treatment. This variation can be quite high between animals and it has been recommended that at least 10 animals per treatment be used if one wishes to quantify apoptosis in a tissue (4). A final item that can become a concern is those situations where the basal apoptotic index is very low (<0.1 %), in which case counting sufficient apoptotic bodies to obtain an index of sufficient confidence may warrant the counting of far more cells than originally intended, perhaps as many as 6000 (3,44). 

Stapleton AM, Zbell P, Kattan MW, et al. Assessment of the biologic markers p53, Ki-67, and apoptotic index as predictive indicators of prostate carcinoma recurrence after surgery. Cancer. 1998 82 168. 

Apoptosis is the programmed death of cells. One can determine from cytologic and cytochemical assays an apoptotic index that is analogous to the LI for proliferation mentioned earlier in this chapter. The balance between cell proliferation and cell death affects tumor growth. ... 

Merchant SH, Gonchoroff NJ, Hutchison RE. Apoptotic index by Annexin V flow cytometry adjunct to morphologic and cytogenetic diagnosis of myelodysplastic syndromes. Cytometry 2001 46 28-32. 

Similarly, Survivin levels were increased in 34 (out of 34) tumor samples (adenocarcinoma and squamous cell carcinoma) when compared with nontumor controls. Survivin expression is frequently observed in tumors from breast cancer patients. One study reported that 71% of breast carcinomas (stages I to IH) were positive for Survivin whereas no expression of Survivin was detected in adjacent normal tissues. In colorectal cancers the expression of Survivin is inversely correlated with the apoptotic index of transformed cells and is significantly related to an increased disease-free survival rate and to a reduced risk for distant metastases. 

Samaha HS, Kelloff GJ, Steele V, Rao CV, Reddy BS. Modulation of apoptosis by sulindac, curcumin, phenylethyL3-methylcaffeate, and 6-phenylhexyl isothiocyanate apoptotic index as a biomarker in colon cancer chemoprevention and promotion. Cancer Res 1997 57 1301-1305. 

It has been shown that CLA was able to protect against 2-amino-3-methylimida-zo[4,5-/]quinoline-induced colon carcinogenesis in F344 rats (25). A recent study (26) demonstrated that 1% dietary CLA significantly decreased colon tumor incidence in the colon of 1,2-dimethylhydrazine (DMH)-treated rats, and the apoptotic index estimated by the terminal deoxynucleotidyl transferase-mediated dUTP nick... 

Hockel M, Schlenger K, Hockel S, Vaupel P (1999) Hypoxic cervical cancers with low apoptotic index are highly aggressive. Cancer Res 59 4525-4528... 

Figure 13.6 (See color insert) Increased tumor uptake of [ In]DTPA-PEG-annexin V. Note the high correlation of tumor uptake of the radiotracer with the apoptotic index (left) and TUNEL staining. This data is reproduced with permission from Ref. (29).

Inducible NOS has been demonstrated to be overexpressed in chronic pancreatitis and in pancreatic cancer and a significant correlation with COX-2 expression was observed, providing evidence of a link between inflammation and tumor development. Other authors have shown a co-expression of the two inducible enzymes in pancreatic adenocarcinoma (Kong et al. 2002), but the activities of the two enzymes have been found to counteract each other COX-2 overexpression positively correlated with high Ki-67 expression and tumor proliferation, and high iNOS expression was significantly associated with a high apoptotic index. 

Lymphoma developed more rapidly in p53 and iNOS donble knockout mice (p53—l—iNOS—l—) or p53—/—iNOS+/— mice than in p53—/—iNOS+/+ mice that were crossbred into C57BL/6 mice (Hnssain et al. 2004). Likewise, sarcoma and lymphomas developed faster in p53+/—iNOS—/— or p53+/—iNOS+/— mice than in p53+/—iNOS+/+ mice (Hnssain et al. 2004). p53—/—iNOS+/+ mice, compared with p53—/—iNOS—/— mice, showed a higher apoptotic index, decreased proliferation index, and an increased expression of CD95L, TRAIL, and the cell cycle checkpoint protein in the spleen and thymns before mmor devel-... 

NCX 4040, 2-(acetyloxy)benzoic acid 4-(nitrooxy-methyl)phenyl ester, combined with either oxaliplatin or 5-FU significantly inhibited tumor growth, prolonged delays in tumor growth, and increased apoptotic indexes compared with those treated with oxaliplatin alone in xenograft models using the three human colon cancer cell lines (WiDr, LoVo, and LoVoDx) (Leonetti et al. 2006). 

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