Expression Of CENP-F MRNA And Ki-67 MRNA And Their Relationship In The Development Of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the occurrence and development of a multi-gene participation, multi-step, multi-stage, multi-factor interactions in vitro and vivo in the complicated process. Its essence is out of control of the cell cycle regulation, and immortalized. Centromere is a important structure which is related to cell proliferation checkpoint control.CENPs is the key element to play a role. As a nuclear matrix protein, CENP-F is the centromere of the protein family of a member of the largest molecular weight, regulates the chromosome movement, and controls the function of the cell cycle.CENP-F plays several important roles in mitotic events, including centromere/kinetochore maturation, chromosome alignment and segragation, and anaphase spindle stabilization. Chromosome segragation is a typical malignant tumor cells cytogenetic characteristics. CENP-F protein accumulates in the nuclear matrix during the cell cycle until it reaches peak levels in G2 and M and is rapidly degraded upon completion of mitosis.Except the expression and function in the normal cells , CENP-F also found in many human tumors in the abnormal expression of the phenomenon, including CENP-F gene amplification and protein overexpression, as well as the serum of patients with anti-CENP-F antibody drops rise. Anti-CENP-F antibody in the serum of patients with lung cancer and breast cancer were identified. Anti-CENP-F antibody found that the splitting of cells increase in the development of tumor and the regulation of cell cycle is dysfunction. Recently, CENP-F has been used in certain human tumor cell proliferation markers.Ki-67 can identify the nuclear protein in the nuclear matrix of proliferation cell. Ki-67 antigen expresses in the mid-G1, is both the subsequent G1, S, G2 and M phase, the highest in the M phase, after M phase it declines rapidly. Application of Ki-67 antisense oligonucleotide could inhibit the proliferation of EM29 cell line.It suggests that Ki-67 protein may play a key role in cells. Foreign scholars on a variety of cancer research shows that Ki-67 proliferative activity is a reflection of the simple, one of the most reliable indicators.Through this experiment,we examined the expression of Centromere protein F (CENP-F) mRNA in six cases of normal oral mucosa (6 / 8), five cases of simple hyperplasia (5 / 7), 20 cases of dysplasia (20/30) and 25 cases of squamous cell carcinoma (25/30) using the real time quantitative reverse transcription-polymerase chain reaction (RT-PCR). The mean expression level of CENP-F mRNA in the oral squamous cell carcinoma is of the highest (0.868±0.091), dysplasia (0.813±0.086) and the simple hyperplasia (0.735±0.089) followed normal oral mucosa (0.720±0.075).At the same time, three cases of normal oral mucosa (3 / 8), four cases of simple hyperplasia (4 / 7), 18 cases of dysplasia (18/30) and 21 cases of squamous cell carcinoma (21/30) were examined by RT-PCR. The mean expression level of Ki-67 mRNA in the oral squamous cell carcinoma is of the highest (0.713±0.076), dysplasia (0.685±0.062) and the simple hyperplasia (0.640±0.059) followed normal oral mucosa (0.532±0.051). The expression of CENP-F mRNA and Ki-67 mRNA are irrelevant to the clinical pathologic factors such as age, sex and location,and contact the clinical stage significantly.The level of their expression in the patients with lymph node metastasis is higher than those without metastasis. The results show that the expression of CENP-F and Ki-67 in normal oral mucosa→simple hyperplasia→dysplasia→squamous cell carcinoma increase gradually. CENP-F mRNA and Ki-67mRNA in squamous cell carcinoma are significantly higher than in other tissues (P<0.05). Nordgard with salivary gland tumors had the consensus of the findings: Ki-67 proliferation index is less than 5%, CENP-F mRNA expression level of the average is low (0.41±0.14), there are good biological behavior; Ki-67 proliferation index is greater than or equal to 5%, CENP-F mRNA expression level of the average is high (1.81±0.48), Ki-67 proliferation index is greater than 10%, a high aggressive biological behavior indicates easy tumor recurrence or metastasis,even death. All this shows that CENP-F and Ki-67 are mutual-induced regulation and synergies in the development of oral squamous cell carcinoma,their mechanism is to be in-depth study. In addition, the expression of CENP-F mRNA in the normal mucosa and simple hyperplasia have no significant difference (P>0.05), and the expression of Ki-67mRNA in normal mucosa and simple hyperplasia have a significant difference (P <0.05).Except the advantage of short half-life, Ki-67 is unable to induce the growth factor. Cells get away from the cell cycle, degrade rapidly and loss their antigenic determinants.These can be a more objective reflection of cell proliferation activity. The expression level of CENP-F mRNA is higher than Ki-67mRNA in the same tissue. Compared to the expression level of Ki-67,CENP-F is more sensitive to disease diagnosis.On the basis of CENP-F and Ki-67 PCR products,we recombinate a plasmid using pMD18-T TA cloning vector. Sequencing of the cDNA sequence found mutations exist, and may cause CENP-F and Ki-67 protein structure and activity change. Therefore,we can speculate that CENP-F and Ki-67 gene mutation may be the important mechanism of strengthening their expression and promoting their development.Such mutation can guide gene therapy of tumor.CENP-F gene control the evolution of the cell cycle and cell growth and differentiation, express abnormal in a variety of human tumors. It is not clear that CENP-F interacts with other centromere proteins and the centromeric DNA, network, the precise dynamics function in the regulation of cell division.At the same time, studying the genes that regulate the cell cycle (such as Rb, Ki-67, cyclin D1 gene, etc.)deeply, is expected to reveal the molecular mechanism of tumors, occurrence and evolution,guide the clinical diagnosis, prognosis judgement and treatment.