Cell proliferation index

Because MIB-1 monoclonal antibody is used extensively to determine the cell proliferation index, its applications are discussed below. This antibody detects the nuclear antigen Ki-67 expressed in proliferating cells but not in resting cells. The antibody reacts with the nuclei of cells in mid-Gj (first gap), S (DNA synthesis), G2 (second gap), and M (mitosis) phases, but not in the G0 or quiescent phases. The use of MIB-1 antibody is one of the simplest and most reliable labeling techniques for assessing the rate of proliferation of a neoplastic cell population. Thus, the antibody can be used to assess the growth fraction (i.e., the number of cells in cell cycle) of normal, reactive, and neoplastic tissues. 

Experimental design The authors investigated the ability of chloroform vapors to produce toxicity and regenerative cell proliferation in female B6C3Fj mice and male Fischer 344 rats. Groups of 5 animals were exposed to 0, 1,3, 10, 30, 100, or 300 ppm chloroform via inhalation for 6 hours a day for 7 consecutive days. Actual exposure concentrations measured for mice were 0, 1.2, 3.0, 10.0, 29.5, 101, and 288 ppm and for rats were 0, 1.5, 3.1, 10.4, 29.3, 100, and 271 ppm. Necropsies were performed on day 8. Animals were administered bromodeoxyuridine (BrdU) via implanted osmotic pump for the last 3.5 days. Cell proliferation was quantitated as the percentage of cells in S-phase (labeling index = LI) measured by the immunohistochemical detection of BrdU-labeled nuclei. 

Administration of hydroquinone (0.5% in the diet) for 20 weeks did not induce hyperplasia or papillomatous lesions in the forestomach in Syrian golden hamsters (Hirose etal., 1986). In male Fischer 344 rats, oral administration of hydroquinone for eight weeks (0.8% in the diet) did not induce hyperplasia or DNA synthesis, as measured by BrdU-labelling index in the forestomach epithelium. No cell proliferation, increased DNA synthesis or increase in pepsinogen-isoenzyme-1-altered neoplastic foci was observed in the pyloric mucosa (Shibata et al., 1990). 

However, be aware that in spite of the usefulness of the MIB-1 antibody in assessing the rate of cell proliferation, the classification of cancers (e.g., breast cancer) by the size of the primary tumor and the presence and extent of lymph node metastases does not adequately explain differences in the clinical outcome of individual patients. Cell proliferation indices are commonly used, along with other diagnostic parameters, to estimate the risk of recurrence of a cancer for individual patients. Therefore, it is important to understand the relationship between various indices of proliferation such as MIB-1 labeling index and detection by either in situ hybridization or polymerase chain reaction. This approach will lead to quality assurance in diagnosis. 

In human studies, flaxseed consumption has had positive impacts on carcinogenesis and parallel observations from animal studies. A doubleblind, placebo-controlled, prospective clinical trial involving 39 women, newly diagnosed with breast tumors, was completed to evaluate the effect of flaxseed consumption on tumor growth (Thompson et al., 2000). Subjects given flaxseed (25 g/day) diets had reduced tumor cell proliferation and c-erB-2 expression, and an increased apoptosis index compared with women who ate whole-wheat muffins. 

Thompson et al. (2005) reported that tumor cell proliferation and c-erbB2 expression decreased by 34% and 71%, respectively, whereas cell apoptosis increased (31%) in menopausal women fed a diet containing 25 g of flaxseed. Changes in c-erbB2 score and apoptosis index were correlated with total flaxseed intake whereas cell proliferation, as measured by Ki-67 labeling index, was not. A main conclusion from these studies was that the lignans and, to a lesser extent, ALA were responsible for the anticarcinogenic activity. 

Figure 6. Staining obtained with two antibody clones to proliferating cell nuclear antigen (PCNA). Antigen retrieval and staining procedures were identical for the two antibodies, (a) Clone 19A2 showed a proliferating index of 75% compared to (b) to a 98% proliferating index in the adjacent section of breast cancer when stained with clone PC 10.

Leong AS-Y, Milios J, Tang SK. Is immunolocalisation of proliferating cell nuclear antigen (PCNA) in paraffin sections a valid index of cell proliferation Appl. Immunohistochem. 1993 1 127-3 5. 

Data on bioactivity on immunocompetent cells provide evidence that D-Ala-deltorphin-I potently (10-9 to 10-11 M) and persistently (up to 4 days) enhances Con A-induced mouse spleen cell proliferation [85]. The peptide increases uptake of thymidine and production of interferon--/ in phytohe-magglutinin-activated human lymphocytes [86] and is 100 times more potent than SNC80 in inhibiting the production of p24 antigen, an index of HIV-1 expression, in Jurkat cells stably transfected with a cDNA encoding for the delta-opiate receptor [87]. 

In most cell populations not all the cells are proliferating, there being a proportion of non-proliferating cells. These may alternatively be described as being in GO or in the A-state. The proliferation index of growth fraction is given by... 

Hall, P. A., Levison, D. A., Woods, A. L, Yu, C. C., Kellock, D. B., Watkins, J. A., Barnes, D M., Gillett, C. E., Camplejohn, R, Dover, R, Wasseem, H, and Lane, D.P. (1990) Proliferating cell nuclear antigen (PCNA) immunolocalization in paraffin sections an index of cell proliferation with evidence of deregulated expression in some neoplasms J Pathol 162, 285-294. 

The results obtained showed the induction of MN in AR42J cells exposed to 2400 and 5700 kBq/mL of "l.u DOTATATE (Fig. 3.14). The frequency of binucleated cells with MN was 4.0% with exposure to 2400 kBq/mL of I Lu DOTATATE and 5.6% with exposure to 5700 kBq/mL of the radionuclide. Compared with basal values of 2.8% for binucleated cells with MN, there was a 1.4- and 2.0-fold increment, respectively. No alteration of the proliferation index was observed (PI = 1.23). 

The DNA ploidy is expressed by the DNA index (DI). For DI = 1, the DNA is normal and classified as DNA diploid for DI 1, the DNA is abnormal and is classified as DNA aneuploid, a state usually associated with neoplastic cells. On the basis of these parameters, additional parameters for comparative estimation were calculated, including the proliferation index (Pl -SxG x Mf to Gy phase ratios and the coefficient of variation (CV). The normal values... 

Peripheral blood mononuclear cells were obtained by density gradient separation through Ficol-Hypaque technology 17). Thymidine incorporation proliferation assays were set up as previously described using human serum albumin (HSA) or STn-HSA as stimulant (77). A stimulation index of > 2 SD compared to normal donors mononuclear cells was used as evidence of positive response. Fifty seven percent of tested vaccinated patients had evidence of specific T cell proliferation against STn. 

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