Comparison of TMA Technique and Routine Whole Slide Analysis in Evaluation of Proliferative Markers Expression in Laryngeal Squamous Cell Cancer.

BACKGROUND/AIM: Comparison of the expression of Ki-67, MCM3, 5, 7 and MTI/II proteins using immunohistochemistry (IHC) on whole section (WS) and tissue microarray (TMA) of laryngeal squamous cell carcinoma (LSCC) samples. MATERIALS AND METHODS: A total of 51 archival paraffin blocks of LSCC were used. TMAs were prepared from 1.5 mm core punches. IHC reactions were performed using antibodies against Ki-67, minichromosome maintenance proteins (MCM3, 5, 7) and metallothionein (MTI/II). RESULTS: Spearman rank correlation test revealed moderate positive correlation in the case of Ki-67: WS vs. TMA (r=0.38, p=0.07) and strong positive correlation in regard to the rest of tested markers: MCM3, WS vs. TMA (r=0.49, p=0.0004); MCM5, WS vs. TMA (r=0.61, p<0.0001); MCM7, WS vs. TMA (r=0.59, p<0.0001); MTI/II, WS vs. TMA (r=0.66, p<0.0001). Mann Whitney U-test showed no significant differences in the case of Ki-67 and MCM5. Moreover, Bland-Altman test showed a low level of bias in regard to Ki-67, WS vs. TMA and MCM5, WS vs. TMA. CONCLUSION: TMA may be an effective and reliable method of assessment of Ki-67 and MCM5 expression in LSCC.

Correlation between levels of expression of minichromosome maintenance proteins, Ki-67 proliferation antigen and metallothionein I/II in laryngeal squamous cell cancer.

MCM2, MCM3 and MCM7 are minichromosome maintenance proteins found in dividing cells and they play a role in DNA synthesis. Increased MCM expression level is observed in cells of different cancer types. Additionally, metallothioneins (MT-I/II) are involved in control of cell proliferation and differentiation and changes of their expression are observed in many types of cancer. Ki-67 is known cancer cell proliferation antigen currently used in prognostic evaluation. The study material consisted of 83 laryngeal squamous cell cancer (LSCC) cases and 10 benign hypertrophic lesions of larynx epithelium as a control group. For the present study, laryngeal cancer cell line HEp-2 and human keratinocytes were employed, and to evaluate expression of all the markers, immunohistochemical method (IHC), immunofluorescence (IF) and western blot analysis were used. Statistical analysis showed strong positive correlation between expression of MCM2, MCM3, MCM7 and Ki-67 antigen in LSCC. Additionally, moderate positive correlation was observed between MCM3 and MT-I/II expression. In cancer cells, the level of expression of MCM3, MCM2, MCM7 and Ki-67 markers was increasing with the grade of LSCC malignancy. IF and western blot analysis showed higher MCM2, MCM3, MCM7 expression in HEp-2 cells in comparison to their expression in keratinocytes. MCM proteins might be useful markers of cell proliferation in LSCC.

Prognostic significance of metallothionein, p53 protein and Ki-67 antigen expression in laryngeal cancer.

BACKGROUND: This study aimed at the evaluation of the expression of metallothionein (MT) in laryngeal carcinoma and its correlation with the expression of Ki-67 antigen and p53 protein and selected clinical and pathological variables in view of their potential prognostic significance. MATERIALS AND METHODS: Sixty-five laryngeal cancer patients were retrospectively analysed. Expression of MT, Ki-67 and p53 in tumour tissue samples were assessed by immunohistochemistry. RESULTS: In laryngeal cancer a significantly augmented expression of MT, Ki-67 and p53 was noted, as compared to the control group (p < 0.001) and a significantly increased expression of MT in low malignancy tumours (G1) as compared to the control group (p < 0.001). The expression of Ki-67 antigen was positively correlated with the expression of p53 protein (r = 0.477; p < 0.05) and expression of either marker was positively correlated with malignancy grade (r = 0.47, p < 0.05; r = 0.31, p < 0.05; for Ki-67 and p53, respectively). Shortened survival was noted in patients with high expression of Ki-67 antigen and p53 protein. CONCLUSION: The intensity of MT expression was not related to prognosis in laryngeal cancer. Nevertheless, it may provide a significant index indicating the malignant transformation of benign lesions of laryngeal epithelium.