The Effect of MMP-9 Inhibitors on the Biological Behavior of Human Oral Squamous Cell Carcinoma SCC15 Cell Line Through PI3K/Akt Signaling Pathway

Objective:To investigate the effect of MMP-9 inhibitor(Mki67)on the biology of human oral squamous cell carcinoma SCC15 cell line and to explore its mechanism of action through PI3K/Akt signaling pathway.Methods:SCC15 cells were extracted,and the supernatant was discarded.The cells were then rinsed twice with PBS,and 0,2.5,5,and 10μL of Mki67(50 mg/mL)were added to the culture respectively.The inhibition rate of cell proliferation was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide(MTT)method,and the cell migration was measured by Transwell chamber test.The cell apoptosis rate was detected by cytometry,and the p-Akt protein content in the cells of each group was determined by a double-antibody sandwich enzyme-linked immunosorbent assay(ELISA)kit.Results:The cell proliferation rates of the 2.5μL,5μL,and 10μL dose groups were all lower than the 0μL group(P<0.05)before treatment,and the cell proliferation rates in the 2.5μL,5μL,and 10μL dose groups decreased overtime(P<0.05).After 24 h,with the increase of Mki67 concentration,the number of migration and invasion gradually decreased(P<0.05),and the number of apoptosis gradually increased(P<0.05);besides,the relative expression of MMP-9,PI3K,and Akt mRNA decreased gradually(P<0.05),and the expression level of Akt mRNA was not statistically significant(P>0.05).Conclusion:MMP-9 inhibitor(Mki67)can inhibit the proliferation and migration of SCC15 cell line and induce apoptosis,and its mechanism of action may be related to the inhibition of PI3K/Akt signaling pathway.

REVERSION OF MALIGNANT PHENOTYPES OF HUMAN LUNG SQUAMOUS CARCINOMA CELLS BY ORNITHINE DECARBOXYLASE ANTISENSE RNA

Abnormally elevated activity of ornithine decarboxylase (ODC), and subsequent polyamine accumulation are intimately associated with the genesis.development and metastasis of cancer. In the present study, to control the growth of tumor cells, ODC antisense RNA was used to transfect human lung squamous carcinoma cell line LTEP-78. Compared with the parental cells, growth of the antisense transfected LTEP-78 cells arrested in G0/Gl phase and colony formation in soft agarose and tumorigenicity in nude mice were significantly reduced. Nucleic acid hybridization demonstrated that the transfectants expressed a high level of ODC antisense RNA and a significantly reduced level of endogenous ODC mRNA.The results suggest that the reversion of malignant phenotypes of human lung squamous carcinoma cells transfected with ODC antisense RNA is associated with the inhibition of polyamine biosynthesis.

Multimodality functional imaging using DW-MRI and 18F-FDG-PET/CT during radiation therapy for human papillomavirus negative head and neck squamous cell carcinoma: Meixoeiro Hospital of Vigo Experience

AIMTo noninvasively investigate tumor cellularity measured using diffusion-weighted magnetic resonance imaging (DW-MRI) and glucose metabolism measured by 18F-labeled fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) during radiation therapy (RT) for human papillomavirus negative (HPV-) head and neck squamous cell carcinoma (HNSCC).METHODSIn this prospective study, 6 HPV- HNSCC patients underwent a total of 34 multimodality imaging examinations DW-MRI at 1.5 T Philips MRI scanner [(n = 24) pre-, during- (2-3 wk), and post-treatment (Tx), and 18F-FDG PET/CT pre- and post-Tx (n = 10)]. All patients received RT. Monoexponential modeling of the DW-MRI data yielded the imaging metric apparent diffusion coefficient (ADC) and the mean of standardized uptake value (SUV) was measured from 18F-FDG PET uptake. All patients had a clinical follow-up as the standard of care and survival status was documented at 1 year.RESULTSThere was a strong negative correlation between the mean of pretreatment ADC (ρ = -0.67, P = 0.01) and the pretreatment 18F-FDG PET SUV. The percentage (%) change in delta (∆) ADC for primary tumors and neck nodal metastases between pre- and Wk2-3 Tx were as follows: 75.4% and 61.6%, respectively, for the patient with no evidence of disease, 27.5% and 32.7%, respectively, for those patients who were alive with disease, and 26.9% and 7.31%, respectively, for those who were dead with disease.CONCLUSIONThese results are preliminary in nature and are indicative, and not definitive, trends rendered by the imaging metrics due to the small sample size of HPV- HNSCC patients in a Meixoeiro Hospital of Vigo Experience.

Relation between the Expression of K-ras in Hep-2 Cells and Development of Laryngeal Carcinoma~*

Objective： To investigate the expression of K-ras in human laryngeal squamous cell carcinoma cell lines （Hep-2） and its significance for establishing a solid foundation for further study of the relationship between human laryngeal squamous cell carcinoma and K-ras gene point mutations. Methods： The expression of K-ras in human laryngeal squamous cell carcinoma cell lines （Hep-2） and human pancreatic carcinoma cell lines （MIAPaCa-2） was detected by using RT-PCR. Results： The expression of K-ras mRNA in Hep-2 and MIAPaCa-2 was strong and positive. Conclusion： The expression of K-ras mRNA in human laryngeal squamous cell carcinoma cell lines （Hep-2） is positive. Development of laryngeal carcinoma might be related to the activation of K-ras gene point mutation.

Effects of ATRA, Acitretin and Tazarotene on Growth and Apoptosis of Tca8113 Cells

Summary：To investigate the effects of ATRA, acitretin and tazarotene on the growth and apoptosis of human tongue squamous cell carcinoma cell line Tca8113. The effect of retinoids on growth of Tca8113 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis with double staining with Annexin V-FITC and PI, and active caspase-3 analysis with the staining of FITC-conjugated monoclonal rabbit anli-active caspase-3 antibody were made by flow cytometer. Streptavidin-biotin complex （SABC） immunocytochemical assays were employed for the detections of Bax/Bcl-2 proteins expressions. Our results showed that the retinoids inhibited growth of Tca8113 cells in a dose-and time-dependent manner with maximal inhibition 24 h after treatment of 10 5 mol/L. 10^-5 mol/L retinoids altered cell cycle distribution of Tca8113 cells, revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. 10^-5 mol/L retinoids significantly induced apoptosis of Tca8113 cells （all P〈0.05）, elevated the cells population with detectable active caspase-3 （P〈 0.05 for all）, increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly （all P〈0.05）. Acitretin played a most prominent role among the retinoids. It is concluded that the inhibition of cell cycle progress of Tca8113 cells by ATRA, acitretin and tazarotene is one of the possible mechanisms for proliferation arrest of TcaS113 cells elicited by the retinoids. The retinoids mediate apoptosis in TcaS113 cells that may be caspase-dependent through mitochondria pathway. High concentration retinoids inhibit growth of Tca8113 cells in vitro by interfering with proliferation and inducing apoptosis of cells. Acitretin may be an alternative medicine for the prevention and treatment of tongue squamous cell carcinoma.

Tumor necrosis factor a accelerates Hep-2 cells proliferation by suppressing TRPP2 expression

TRPP2, a Ca2＋-permeable non-selective cation channel, has been shown to negatively regulate cell cycle, but the mechanism underlying this regulation is unknown. Tumor necrosis factor a （TNF-a） is a proinflammatory cytokine extensively involved in immune system regulation, cell proliferation and cell survival. However, the effects and mechanisms for the role of TNF-a in laryngeal cancer remain unclear. Here, we demonstrated using western blot analyses and intracellular Ca〉 concentration measurements that TNF-a treatment suppressed both TRPP2 expression and ATP-induced Ca2＋ release in a laryngeal cancer cell line （Hep-2）. Knockdown of TRPP2 by a specific siRNA significantly decreased ATP-induced Ca2＋ release and abolished the effect of TNF-a on the ATP-induced Ca2＋ release. TNF-a treatment also enhanced Hep-2 cell proliferation and growth, as determined using cell counting and flow cytometry cell cycle assays. Moreover, TNF-a treatment down-regulated phosphorylated protein kinase R-like endoplasmic reticulum kinase （p-PERK） and phosphorylated eukaryotic translation initiation factor （p-elF2c0 expression levels, without affecting PERK and elF2ct expression levels in Hep-2 cells. We concluded that suppressing TRPP2 expression and TRPP2-mediated Ca2＋ signaling may be one mechanism underlying TNF〈t-enhanced Hep-2 cell proliferation. These results offer new insights into the mechanisms of TNF-a-mediated laryngeal cancer cell proliferation, and provide evidences showing a potential role of TNF-a in the development of laryngeal cancer.