The Expression Of HPIP In Nasopharyngeal Carcinoma And Its Effect On Proliferation And Apoptosis Of Nasopharyngeal Carcinoma Cells

BackgroundNasopharyngeal carcinoma(NPC)is a malignant tumor of head and neck with regional distribution and familial aggregation,which frequently occurs in Southeast Asia and South China.Its incidence rate is the first among the malignant tumors of the ENT.NPC is dominated by low differentiated or undifferentiated squamous cell carcinoma with a high degree of malignancy and is highly sensitive to radiotherapy.Neck lymph node metastasis may occur in the early stage of NPC.The location of NPC is hidden,and it is not easy to detect early,often to the middle and late stage to find the disease.At the time of diagnosis,about 70-80%of patients are in middle and advanced stages,leading to poor prognosis in most NPC patients.At present,the radiotherapy effect of early NPC patients is very good,and the 5-year survival rate can be as high as 90%,while the radiotherapy effect of advanced patients alone is poor,and the 5-year survival rate is only about 50%.Radiotherapy and chemotherapy are the main clinical treatments for locally advanced NPC.Although radiotherapy and chemotherapy have improved survival rates in recent years,local recurrence and distant metastasis are still the reasons for the failure of NPC treatment.Therefore,the study of the pathogenesis,invasion and metastasis mechanism of NPC is of great clinical significance for its treatment and prognosis.Human hematopoietic PBX-interacting protein(HPIP)can interact with PBX to inhibit the transcriptional activation of E2A-PBX1,regulate the normal growth and differentiation of hematopoietic stem cells,inhibit the occurrence of leukemia,and regulate the occurrence and development of tumors by affecting PI3K-AKT-mTOR,MAPK and hedgehog signaling pathways.HPIP is not only highly expressed in a lots of tumor cells and cancer tissues,but also plays an important role in the regulation of tumor cell proliferation,apoptosis,invasion/migration and so on.However,there have been no reported studies on the correlation between HPIP and nasopharyngeal carcinoma.Our study was designed to investigate the expression of HPIP in NPC tissues,and the effect of HPIP on the biological characteristics of NPC cells.Explore the relationship between HPIP expression and the occurrence and development of NPC.Materials and methods1.Immunohistochemical analyses were used to detect the protein expression of HPIP in 46 cases of NPC and 20 cases of chronic nasopharyngitis.The difference between two groups was compares by chi-square.Logistic regression analysis was used to study the correlation between HPIP protein expression level and clinicopathological characteristics of patients with NPC.2.Lipofectamine 2000 was used to transient transfect HNE-1 cell lines.Fluorescence microscope determined the success of transfection after 24 hours.Then,western blot was performed to assess the expression of HPIP in transfected NPC cells for 24 hours.And the siRNA with the most significant HPIP silencing effect was selected.3.Cell biological function test:After HPIP expression was inhibited by optimal siRNA,the proliferation ability of NPC cells was detected by CCK8 method and the change of apoptosis level was detected by flow cytometry.The survival rate and apoptosis rate were compared between groups by One-way analysis of variance.Results1.The immunohistochemical results showed that the protein expression of HPIP was mainly found in the cytoplasm.In 46 cases of NPC group,the positive expression rate of HPIP protein was 69.6%,in 20 cases of chronic nasopharyngitis organization,the positive expression rate was 5%.The difference between the two groups have statistical significance(P<0.05).2.The best siRNA to inhibit the expression of HPIP protein was successfully screened,which confirmed that the down-regulation of HPIP expression could significantly inhibit the proliferation,survival ability of NPC cells in vitro,and promote the level of apoptosis.Conclusion1.The expression of HPIP was significantly different between NPC and chronic nasopharyngitis,and HPIP was highly expresses in NPC tissues.However,there was no significant correlation between HPIP protein expression level and gender,age,TNM stage and clinical stage.2.Silencing the expression of HPIP in NPC cells significantly inhibited the proliferation of NPC cells and promoted apoptosis.