Upregulation of miR-153 promotes cell proliferation via downregulation of the PTEN tumor suppressor gene in human prostate cancer.

BACKGROUND: Accumulating evidence indicates that microRNAs play a pivotal role in the development and progression of prostate cancer. The present study was aimed at clarifying the biological functions of miR-153, one of the upregulated microRNAs in prostate cancers, and the signaling transduction induced by miR-153. METHODS: miR-153 was identified to be overexpressed in prostate cancers. The probable biological function of miR-153 in cellular proliferation was then examined by diverse assays, such as MTT, colony formation and BrdUrd incorporation assay. Moreover, real-time PCR and western blotting analysis were applied to investigate the underlying molecular mechanism induced by miR-153. Luciferase assays were used to determined the FOXO1 transactivity and the direct regulation of PTEN-3'-UTR by miR-153. RESULTS: High-throughput method identified miR-153 to be upregulated in prostate cancers, which is further confirmed by the upregulated expression in four paired prostate tumor/adjacent non-cancerous tissues from the same patients. Further studies revealed that overexpression of miR-153 promoted cell cycle transition and cell proliferation, while inhibition of miR-153 reduced this effect. Moreover, miR-153 overexpression in prostate cancer cells increased the G1/S transitional promoter, cyclin D1 expression, and decreased cyclin-dependent kinase (CDK) inhibitor, p21(Cip1) expression. In addition, we demonstrated that miR-153 directly targeted the PTEN tumor suppressor gene, activated the AKT signaling and downregulated FOXO1 transcriptional activity. CONCLUSIONS: Taken together, our results suggest that miR-153 play an important role in promoting proliferation of human prostate cancer cells and present a novel mechanism of microRNA-mediated direct suppression of PTEN expression in prostate cancer cells.

MiRNA-329 targeting E2F1 inhibits cell proliferation in glioma cells.

BACKGROUND: MicroRNAs have recently emerged as key regulators of cancers, miR-329 located on 14q32.31 is one of down-regulated miRNAs in glioma, but the function and molecular mechanisms of miR-329 in determining the malignant phenotype of human glioma are elusive. This study therefore was conducted to investigate the role of miR-329 in biological behaviors of human glioma LN18 and T98G cell lines and its molecular mechanisms. METHODS: Nine patients with GBM were analyzed for the expression of miR-329 by quantitative RT-PCR. MiR-329 overexpression was established by transfecting miR-329 precursor into LN18 and T98G cells, and its effects on cell proliferation were studied using MTT assay, anchorage-independent growth ability assay, colony formation assays, Bromodeoxyuridine labeling and immunofluorescence.The effects of miR-329 on cell cycle were studied by flow cytometry. The target of miR-329 was determined by luciferase assays. The regulation of miR-329 on Akt pathway was determined by western blot. RESULTS: The E2F1 was identified as the target of miR-329. Overexpression of miR-329 blocked G1/S transition in LN18 and T98G cell lines, dramatically suppressed cell proliferation and the ability of colony formation. MiR-329 significantly decreased the phosphorylation levels of intracellular kinases Akt and expression of cyclin D1, but the expression of p21 was upregulated, cell growth was suppressed by inhibiting E2F1-mediated Akt pathway. CONCLUSIONS: MiR-329 may inhibit cell proliferation in human glioma cells through regulating E2F1-mediated suppression of Akt pathway.

Association between ATM 5557G>A polymorphism and breast cancer risk: a meta-analysis.

Epidemiological studies have evaluated the association between ATM 5557G>A (p.D1853N) polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the relationship, we performed this meta-analysis. Systematic searches of PubMed and Medline databases were performed. A total of nine studies included 3155 cases and 2752 controls were identified. When all nine studies were pooled into the meta-analysis, there was no evidence for significant association between 5557G>A mutation and breast cancer risk(for G/A vs. G/G: OR = 1.05, 95% CI = 0.83-1.34; for A/A vs. G/G: OR = 0.77, 95% CI = 0.58-1.03; for dominant model: OR = 1.04, 95% CI = 0.82-1.31; for recessive model: OR = 0.87, 95% CI = 0.69-1.09). In the subgroup analyses by family history and ethnicity, significant associations were found among Amerindians (for G/A vs. G/G: OR = 2.19, 95% CI = 1.38-3.47; for dominant model: OR = 2.15, 95% CI = 1.37-3.38). In summary, the meta-analysis suggest that ATM 5557G>A polymorphism is associated with increased breast cancer risk among Amerindians. However, due to the small subjects included in analysis and the selection bias existed in some studies, the results for Amerindians should be interpreted with caution.

Toremifene versus tamoxifen for advanced breast cancer.

BACKGROUND: Toremifene (TOR) and tamoxifen (TAM) can both be used as treatments for advanced breast cancer. OBJECTIVES: To compare the efficacy and safety of TOR with TAM in patients with advanced breast cancer. SEARCH METHODS: The Cochrane Breast Cancer Group's Specialised Register was searched (1 July 2011) using the codes for "toremifene", "fareston", "tamoxifen, "nolvadex, and "breast cancer". We also searched MEDLINE (via PubMed) (from inception to 1 July 2011), EMBASE (via Ovid) (from inception to 1 July 2011), The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 7, 2011), and the WHO International Clinical Trials Registry Platform search portal (1 July 2011). In addition, we screened the reference lists of relevant trials or reviews. SELECTION CRITERIA: Randomised controlled trials (RCTs) that compared the efficacy and safety, or both of TOR with TAM in women with advanced breast cancer. Trials that provided sufficient data on one of the following items: objective response rate (ORR), time to progression (TTP), overall survival (OS), and adverse events, were considered eligible for inclusion. DATA COLLECTION AND ANALYSIS: Studies were assessed for eligibility and quality. Two review authors independently extracted the following details: first author, publication year, country, years of follow-up, treatment arms, intention-to-treat (ITT) population size, menopausal status of patients, hormone receptor status, response criteria, efficacy and safety outcomes of TOR and TAM arms. Hazard ratios (HR) were derived for time-to-event outcomes, where possible, and response and adverse events were analysed as dichotomous variables. We used a fixed-effect model for meta-analysis unless there was significant between-study heterogeneity. MAIN RESULTS: A total of 2061 patients from seven RCTs were included for final analysis, with 1226 patients in the TOR group and 835 patients in the TAM group. The ORR for the TOR group was 25.8% (316/1226) whereas, the ORR for the TAM group was 26.9% (225/835). The pooled risk ratio (RR) suggested that the ORRs were not statistically different between the two groups (RR 1.02, 95% confidence interval (CI) 0.88 to 1.18, P = 0.83). The median TTP was 6.1 months for the TOR group and 5.8 months for the TAM group. The median OS was 27.8 months for the TOR group and 27.6 months for the TAM group. There were no significant differences in TTP and OS between the two therapeutic groups (for TTP: HR 1.08, 95% CI 0.94 to 1.24; for OS: HR 1.02, 95% CI 0.86 to 1.20). The frequencies of most adverse events were also similar in the two groups, while headache seemed to occur less in the TOR group than in the TAM group (RR 0.14, 95% CI 0.03 to 0.74, P = 0.02). There was no significant heterogeneity between studies in most of the above meta-analyses. Sensitivity analysis did not alter the results. AUTHORS' CONCLUSIONS: TOR and TAM are equally effective and the safety profile of the former is at least not worse than the latter in the first-line treatment of patients with advanced breast cancer. Thus, TOR may serve as a reasonable alternative to TAM when anti-oestrogens are applicable but TAM is not the preferred choice for some reason.

Lack of association between CYP17 MspA1 polymorphism and breast cancer risk: a meta-analysis of 22,090 cases and 28,498 controls.

Epidemiological studies have evaluated the association between CYP17 MspA1 polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the relationship, we performed this meta-analysis. Systematic searches of the PubMed and Medline databases were performed. A total of 35 studies including 22,090 cases and 28,498 controls were identified. Genotype distributions of CYP17 in the controls of all studies were in agreement with Hardy-Weinberg equilibrium (HWE) except for three studies. When all 35 studies were pooled into the meta-analysis, there was no evidence for significant association between CYP17 MspA1 polymorphism and breast cancer risk (for A1/A2 vs. A1/A1: OR = 1.00, 95% CI = 0.96-1.04; for A2/A2 vs. A1/A1: OR = 1.03, 95% CI = 0.97-1.08; for dominant model: OR = 1.01, 95% CI = 0.97-1.05; for recessive model: OR = 1.03, 95% CI = 0.98-1.08). In the subgroup analyses by ethnicity, menopausal status and source of controls, no significant associations were found in all genetic models. When sensitivity analyses were performed by excluding HWE-violating studies, all the results were not materially altered. In summary, the meta-analysis strongly suggests that CYP17 MspA1 polymorphism is not associated with increased breast cancer risk.

URG4 expression is a novel prognostic factor for the progression of nasopharyngeal carcinoma and overall survival of patient.

URG4, a novel oncogene, is involved in the development and progression of various tumors. This study investigated the clinicopathological significance of URG4 in nasopharyngeal carcinoma (NPC). We used five NPC tissues and adjacent normal nasopharyngeal tissues to determine URG4 expression and found that URG4 was upregulated in NPC tissues. Immunohistochemistry analysis found URG4 was expressed positively in 97.1% (99/102) of NPC samples and highly expressed in 41.2% (42/102) of NPC samples. Its level was positively correlated with advancing clinical stage. Kaplan-Meier analysis with the log-rank test found that patients with high URG4 expression had poor outcome and patients with low URG4 expression had better survival. Statistical analysis showed that there was a significant correlation between URG4 expression and clinical stage, larger tumor size, and lymph node involvement. Cox-regression analysis showed that URG4 expression could serve as a prognostic factor for NPC patients. In summary, this study showed that URG4 was upregulated in NPC tissues, patients with high URG4 expression had poor outcome, and URG4 was found to be a valuable biomarker for NPC progression.

Upregulated microRNA-143 inhibits cell proliferation in human nasopharyngeal carcinoma.

The aim of the present study was to investigate the possible functions and mechanism of microRNA (miR)-143 in cell proliferation of human nasopharyngeal carcinoma (NPC). The expression of miR-143 in NPC cells and tissues was investigated using reverse transcription-quantitative polymerase chain reaction. Cell viability assay, colony formation assay and flow cytometry were used to examine the cell proliferative ability and tumorigenicity. The expression levels of p21Cip1, p27Kip1, cyclin D1, phosphorylated (p)-retinoblastoma protein (Rb), Rb and cyclin-dependent kinase (CDK) 6 were determined by western blotting. Luciferase assay was used to confirm whether CDK6 was a direct target of miR-143. miR-143 was downregulated in NPC cell lines and tissues. Overexpression of miR-143 in NPC CNE1 cells inhibited proliferation, tumorigenicity and cell cycle progression. Additionally, ectopic expression of miR-143 downregulated cyclin D1 and p-Rb expression, and upregulated p21Cip1 and p27Kip1 expression, which subsequently inhibited NPC cell proliferation. It was also observed that CDK6 was a direct target of miR-143, which downregulated CDK6 expression. CDK6 suppression by miR-143 was associated with dysregulated expression of p21Cip1, p27Kip1, cyclin D1 and p-Rb, thereby serving an essential role in NPC cell growth. Our findings suggest that miR-143 inhibits proliferation by targeting CDK6, and may aid to identify new targets for anti-oncomiRs.

microRNA-214 functions as a tumor suppressor in human colon cancer via the suppression of ADP-ribosylation factor-like protein 2.

microRNAs (miRNAs/miRs) are a conserved class of endogenous, short non-coding RNAs that post-transcriptionally regulate the expression of genes involved in diverse cellular processes. miR-214 has been reported to be associated with several cancers, including human colon cancer. However, the function of miR-214 in colon cancer development is poorly understood. In the current study, miR-214 was demonstrated to be downregulated in colon cancer tissues compared with healthy colon tissues. Functional studies showed that miR-214 overexpression results in the inhibition of cell viability, colony formation and proliferation, and the induction of cell apoptosis. ADP-ribosylation factor-like protein 2 (ARL2) is predicted to be a target candidate of miR-214. A luciferase reporter assay, western blot analysis and quantitative polymerase chain reaction were performed, which revealed that miR-214 negatively regulates ARL2 expression by targeting its 3' untranslated region directly. In conclusion, the results of the present study revealed that miR-214 suppresses colon cancer cell growth via the suppression of ARL2, and indicated that miR-214 may present a significant potential therapeutic target for colon cancer.

Cathepsin L is involved in proliferation and invasion of ovarian cancer cells.

Cathepsin L (CTSL) is a lysosomal cysteine protease that has been found to be overexpressed in ovarian cancer (OC). The aim of the present study was to investigate the possible involvement of CTSL in the development of OC. In this study, RNA interference with a CTSL small hairpin RNA (CTSL-shRNA), and a plasmid carrying CTSL were used to identify the effects of this enzyme on the regulation of the malignant behavior of OC cells. OV-90 and SKOV3 human ovarian cancer cell lines were selected as cell models in vitro and in vivo. The results showed that downregulation of CTSL significantly inhibits the proliferative and invasive capability of SKOV3 cells, and that upregulation of CTSL in OV-90 cells leads to opposite effects. Compared with parental OC cells, cells in which CTSL was silenced exhibited a reduced capacity to develop into tumors in nude mice, while the growth of tumor xenografts derived from these cells was markedly constrained. In conclusion, the results suggested that CTSL contributes to the proliferation and metastasis of OC, and that CTSL may be a novel molecular target for OC treatment.

[Diagnostic value of combined detection of TPS, NSE and CEA in lung cancer].

OBJECTIVE: To study the diagnostic value of combined detection of 3 tumor markers, namely tissue polypeptide specific antigen (TPS), neuro-specific enolase (NSE) and carcinoembryonic antigen (CEA), in patients with lung cancer. METHODS: The serum levels of TPS, NSE and CEA were determined by enzyme-linked immumosorbent assay in 72 patients with lung cancer and 114 healthy adults. RESULTS: The levels of the 3 tumor markers in the patient group were significantly higher than those of the healthy control group (P<0.001). The sensitivity of TPS for lung cancer detection was 84.7% with specificity of 89.4%, which were 54.1% and 91.2% respectively for NSE, and 45.8% and 91.4% respectively for CEA. The combined detection of the 3 tumor markers for lung cancer diagnosis had a sensitivity of 100%. CONCLUSIONS: TPS, NSE and CEA employed separately are helpful in the diagnosis of lung cancer, and their combined detection may significantly improve the sensitivity for lung cancer detection, due to the obvious complementarity of the 3 markers.

[Clinical study of serum tissue polypeptide-specific antigen in breast cancer].

OBJECTIVE: To investigate the expression of serum tissue polypeptide-specific antigen (TPS) in breast cancer patients and its clinical value in such cases. METHODS: Altogether 160 subjects (90 patients with breast cancer, 40 with benign breast lesions, and 30 healthy subjects) were enrolled in this study. The serum TPS and CA153 levels were measured by ELISA in all the subjects. RESULTS: The levels and positivity rate of serum TPS and CA153 in breast cancer group were significantly higher than those in the normal subjects group and benign lesion group (P<0.01), and became even higher as the malignancy progressed. High serum TPS level was detected in the cancer patients in stage I. Serum TPS level was the most sensitive to bone metastasis of the malignancy, but its highest levels occurred in cases of lymphoid node metastasis (P<0.05). In patients who responded favorably to the treatment, serum TPS and CA153 levels were significantly reduced (P<0.05), but the reduction in TPS levels tended to be more obvious (P<0.05). CONCLUSION: Serum TPS can be used as a very useful and sensitive tumor marker in the diagnosis of breast cancer, especially in case of bone metastasis, and may be of great value in clinical decision-making and assessment of therapeutic effect.

Hyperleukocytosis: A report of five cases and review of the literature.

Hyperleukocytosis (white blood cell count, >100×109/l), an uncommon presentation of leukemia, is associated with an increased risk of early mortality. It may present with a variety of symptoms secondary to leukostasis, a syndrome caused by the sludging of circulating leukemic blasts in the microvasculature. Adequate measures for managing this medical emergency include hydration, cytoreduction, prevention of tumor lysis and, rarely, leukapheresis in cases complicated by leukostasis and hyperviscosity syndrome. The present study reports a case series of five patients with hyperleukocytic leukemia. In addition, a review of the literature with regard to the incidence, pathophysiology, clinical manifestations and management of this laboratory abnormality is included. This study demonstrated that the central nervous system and lungs are the most common sites for leukostasis, and that emergency cases require aggressive treatment.

[Expression of miR-143 in nasopharyngeal carcinoma cell lines and its effect on cell adhesion ability].

OBJECTIVE: To detect miR-143 expression in human nasopharyngeal carcinoma (NPC) cell lines and explore the role of miR-143 in regulating the adhesion ability of NPC cells. METHODS: Fluorescence quantitative RT-PCR was used to detect miR-143 expression levels in 5 NPC cell lines (CEN1, CNE2, HONE1, 5-8F, and 6-10B) and an immortalized human nasopharyngeal epithelial cell line (NP69). The retrovirus plasmid pMSCV-puro-miR-143 was constructed and the packaged retroviruses pMSCV-puro and pMSCV-puro-miR-143 were infected in 5-8F cells to establish a cell line with stable miR-143 overexpression, whose adhesion ability was tested with adhesion assay. RESULTS: The expression of miR-143 was down- regulated in the NPC cell lines, and the highly metastatic NPC cell line 5-8F had a expression of only 3.0% of the control level, as compared with the level of 63.59% in the tumorigenic but nonmetastatic NPC cell line 6-10B. The transfected 5-8F cells showed a 1080-fold increase of miR-143 expression (P<0.05) with a significantly lowered adhesion ability. CONCLUSION: miR-143 plays a role in regulating the invasiveness and metastasis of NPC, and overexpression of miR-143 causes a significant reduction of the adhesion ability of the highly metastatic NPC cell line 5-8F.

[MiR-143 inhibits migration of human nasopharyngeal carcinoma cells by negatively regulating GLI3 gene].

OBJECTIVE: To investigate the possible biological function and mechanism of miR-143 in the metastasis of human nasopharyngeal carcinoma (NPC). METHODS: Using bioinformatics to predict the target gene of miR-143, the 3'UTR and mutant 3'UTR of GLI3 gene was cloned into psiCHECK-2 vector. Dual-luciferase reporter gene assay was employed to examine the repression of the GLI3 gene. miR-143 and GLI3 expression levels in 5-8F cells transfected with miR-143 mimics, inhibitor, or siGLI3 were examined, and the changes in the cell migration ability was assessed by Transwell invasion assay. RESULTS: Bioinformatics prediction indicated the Hh pathway transcription gene GLI3 as a target gene of miR-143, and dual-luciferase reporter assay showed that miR-143 directly combined with the 3'UTR of GLI3. qRT-PCR and Western blotting demonstrated that the expression of miR-143 in 5-8F cells was negatively correlated to GLI3 and suppressed the migration of 5-8F cells. CONCLUSION: MiR-143 can inhibit the invasion of NPC cells by negative regulation of GLI3 gene, which sheds light on the role of miR-143 and Hh pathway in NPC.

Sam68 is a novel marker for aggressive neuroblastoma.

BACKGROUND: Neuroblastoma (NB) is the most common solid extracranial tumor in children. However, the molecular mechanism and progression of NB is largely unknown, and unfortunately, the prognosis is poor. Src-associated in mitosis with a molecular weight of 68 kDa (Sam68) is associated with carcinogenesis and neurogenesis. The present study aimed to investigate the clinical and prognostic significance of Sam68 in NB. METHODS: The expression of Sam68 in immortalized normal epithelial cells, NB cell lines, and in four cases of paired NB tissue and adjacent normal tissue from the same patient was examined using Western blotting, reverse transcription-polymerase chain reaction (PCR) and real-time reverse transcription-PCR. The proliferation of NB cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, Sam68 protein expression was analyzed in 90 NB cases characterized as clinicopathological using immunohistochemistry. Statistical analyses were applied to evaluate the diagnostic value and associations of Sam68 with clinical parameters. RESULTS: Western blotting and reverse transcription-PCR showed that the expression level of Sam68 was markedly higher in NB cell lines than in the immortalized normal epithelial cells at both messenger RNA and protein levels. The MTT assay revealed that Sam68 expression supported proliferation of NB cells. Sam68 expression levels were significantly up-regulated in tumor tissues in comparison to the matched adjacent normal tissues from the same patient. Sam68 protein level was positively correlated with clinical stage (P<0.001), tumor histology (P<0.001), and distant metastasis (P=0.029). Patients with higher Sam68 expression had shorter overall survival time, whereas those with lower tumor Sam68 expression had longer survival time. CONCLUSION: Our results suggest that Sam68 expression is associated with neuroblastoma progression and may represent a novel and valuable predictor for prognostic evaluation of neuroblastoma patients.

[Therapeutic effect of axitinib and 5-FU in nude mice bearing human colon cancer xenograft].

OBJECTIVE: To study the inhibitory effect and toxicity of axitinib combined with 5-FU in nude mice bearing transplanted tumor of colon cancer LoVo cells. METHODS: Nude mouse models bearing LoVo colon cancer xenograft were randomized into vehicle control group, untreated control group, axitinib-treated group, 5-FU-treated group and combined treatment group for corresponding treatments. The tumor dimensions, body weight and tumor weight were recorded, and the efficacy and toxicity were evaluated in terms of complete remission (CR), partial remission (PR), tumor growth delay (TGD), mortality rate and net body weight loss. RESULTS: The combined treatment showed a significantly stronger efficacy than axitinib or 5-FU used alone. TGD of the combined treatment group was 16.73 days, longer than that of axitinib (8.53 days) and 5-FU (9.72 days) used alone. No mouse died during the treatments in the untreated control group, and 1 died in each of the other 4 groups. The mortality rate and weight loss were both less than 20%. One mouse had PR in axitinib-treated group and another in the combination treatment group. Axitinib, alone and in combination with 5-FU, reduced ABCG2 expression in the tumor tissue, and 5-FU has no such effect. CONCLUSION: Combination of axitinib and 5-FU produces better antitumor effect than either drug used alone and is well tolerated in nude mice bearing colon cancer xenograft.

[Role of centromere protein H in human gastric cancer cell proliferation].

OBJECTIVE: To explore the role of centromere protein H (CENP-H) in the proliferation of human gastric cancer cells. METHODS: RT-PCR and Western blot analysis were employed to examine the mRNA and protein expressions of CENP-H in 7 human gastric cancer cell lines and immortalized human gastric epithelial cells (GES-1). The cells were infected with the retrovirus vectors pMSCV-CENP-H or CENP-H-RNAi to establish stable cell lines with high CENP-H expression or CENP-H expression interference. MTT assay and colony formation assay were used to examine the changes in the cell proliferation after the infection. RESULTS: CENP-H was over-expressed in gastric cancer cell lines AGS, BGC823, SGC-7901, MKN45, HGC27, MGC-803 and MKN28 at both mRNA and protein levels. The established AGS/CENP-H cell line with increased CENP-H expression showed enhanced proliferative activity, while the cell line MGC-803/CENP-H-RNAi with CENP-H expression interference showed an obviously lowered proliferation ability. CONCLUSION: CENP-H promotes the proliferation of human gastric cancer cells, suggesting its important role in the occurrence and development of gastric cancer.

MiR-219-5p inhibits hepatocellular carcinoma cell proliferation by targeting glypican-3.

MicroRNAs (miRNAs) have been linked to the molecular pathogenesis of many cancers. In this study, we found that miR-219-5p was significantly downregulated in 83 HCC tissues and three HCC cell lines, compared to their non-tumor counterparts. MiR-219-5p expression correlated with tumor size, histological differentiation, and overall survival time in HCC patients. We also found that miR-219-5p could inhibit cell proliferation in vitro and arrest cell cycle at the G1 to S transition. Further studies identified that miR-219-5p reduced both the mRNA and protein levels of glypican-3 (GPC3). These findings indicate that miR-219-5p exerts tumor-suppressive effects in hepatic carcinogenesis through negative regulation of GPC3 expression.

Silencing TRPC1 expression inhibits invasion of CNE2 nasopharyngeal tumor cells.

The invasion and metastasis processes involved in nasopharyngeal carcinoma (NPC) remain enigmatic. Transient receptor potential channel-related protein 1 (TRPC1) is a cation channel involved in diverse cellular functions by precisely controlling Ca2+. The role of this unique TRPC member in nasopharyngeal malignancies has not yet been delineated. Here, we downregulated TRPC1 in CNE2 cells by RNAi technology and by using 2-APB, an inhibitor of the inositol 1,4,5-trisphosphate (IP3) receptor and of store-operated Ca2+ channel-mediated Ca2+ entry. Both types of TRPC1 inhibition resulted in significantly attenuated adhesive and invasive abilities, suggesting that TRPC1 can modulate the metastasis of NPC. These findings support further investigation of the potential of TRPC1 as a novel therapeutic target for intervention in nasopharyngeal carcinoma.

[Gefitinib enhances the radiosensitivity of nasopharyngeal carcinoma cell line CNE2 in vitro].

OBJECTIVE: To study the radiosensitizing effect of gefitinib on nasopharyngeal carcinoma cell line CNE2 in vitro. METHODS: Nasopharyngeal carcinoma cell line CNE2 was cultured in RP2MI 1640. MTT assay was performed to evaluate the cell proliferation changes in response to gefitinib treatment and the radiosensitizing effect of gefitinib. The cell survival curves and sensitive enhancement ratio (SERs) were obtained with a clonogenic assay. Flow cytometry analysis was applied to detect the cell cycle changes and cell apoptosis. RESULTS: MTT assay showed that cells exposed to gefitinib and radiation had a significantly lower survival ratio compared to the cells with radiation exposure only (0.582∓0.012 vs 0.398∓0.016, P=0.002), with a SER of 1.535∓0.134. The S phase cell percentage was significantly decreased and G(2)-M phase cells increased in gefitinib plus radiation group (P=0.000), suggesting a synergistic effect of gefitinib and radiation. CONCLUSION: Gefitinib can enhance the radiosensitivity of nasopharyngeal carcinoma CNE2 cells in vitro possibly by inhibiting cell proliferation, inducing cell apoptosis, and causing changes in the cell cycle distribution.