OBJECTIVETo investigate the effects of HIF-1α on adhesion and invasion of human nasopharyngeal carcinoma CNE-1 cells under hypoxia and underlying molecular mechanisms.

METHODSCoCl₂was used to mimic tumor hypoxic microenvironment. mRNA and protein expressions of HIF-1α, E-cadherin and CXCR4 in CNE-1 cells at different hypoxic time phases were detected by RT-PCR and ELISA respectively. The influences of silencing HIF-1α using RNA interference on E-cadherin and CXCR4 expressions were evaluated. Adhesion test Transwell invasion test were used to evaluate the effects of HIF-1α gene silencing on cell adhesion and invasion.

RESULTSUnder hypoxia, HIF-1α mRNA expression in CNE-1 cells was stable, but its protein expression increased obviously (P<0.05). Both mRNA and protein expressions of E-cadherin were decreased significantly with prolonged hypoxia, while mRNA and protein expressions of CXCR4 increased significantly (P<0.05). After silencing HIF-1α gene, expression of E-cadherin protein was up-regulated, but with down-regulated expression of CXCR4 protein, with a decrease significantly in adhesion rate or invasive cell number of CNE-1 cells (P<0.05).

CONCLUSIONSHypoxia can increase HIF-1α protein expression in nasopharyngeal carcinoma cell line CNE-1. Silencing HIF-1α by RNA interference can reduce inhesion and invasion abilities of CNE-1 cells, which may be mediated by down-regulating E-cadherin expression and up-regulating CXCR4 expression.

Cadherins ; genetics ; metabolism ; Carcinoma ; Cell Hypoxia ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Nasopharyngeal Neoplasms ; genetics ; pathology ; RNA Interference ; RNA, Messenger ; Receptors, CXCR4 ; genetics ; metabolism

OBJECTIVETo explore the patterns and influencing factors of lymph node metastasis in limited esophageal small cell carcinoma (PESCC).

METHODSA total of 98 limited stage PESCC patients who underwent surgery were selected for this study. The lymph node metastasis ratio at different sites, depth of invasion, tumor length and other factors were analyzed to assess their influence on lymph node metastasis.

RESULTSAmong the 98 PESCC cases, 46 cases had lymph node metastasis (46.9%). 100 out of 833 lymph nodes had metastasis, with a metastasis ratio of 12.0%. For upper thoracic esophageal small cell carcinomas, lymph node metastasis ratios were 42.9%, 12.5%, 0 and 0 in the superior mediastinum, middle mediastinum, inferior mediastinum and abdominal cavity, respectively. In the middle thoracic PESCCs, the lymph node metastasis ratios were 18.8%, 7.7%, 15.7%, and 15.3%, respectively. In the lower thoracic PESCCs, the lymph node metastasis ratios were 0, 0, 27.3% and 23.5%, respectively. Lymph node metastasis rates in PESCCs at stages T1, T2, T3, T4 were 15.4%, 42.3%, 63.9%, and 80.0%, respectively. The lymph node metastasis ratios in PESCCs at stages T1, T2, T3, T4 were 2.0%, 8.3%, 17.8% and 25.0%, respectively. Lymph node metastasis rate and lymph node metastasis ratio at different T stages were of significant difference (P<0.05 for all). Lymph node metastasis rates in patients with tumor <3 cm, 3-5 cm, and >5 cm were 30.6%, 46.9% and 66.7%, respectively, and lymph node metastasis ratios were 5.4%, 11.0% and 21.1%, respectively. Lymph node metastasis rate and lymph node metastasis ratio in patients with different tumor length had significant differences (P<0.05 for all). Lymph node metastasis ratio was 11.6% in the Chr-A negative and weak positive group, much higher than 4.3% in the Chr-A positive group (P=0.013). There was a tendency that lymph node metastasis ratio of NSE-positive group was higher than that of NSE-negative and weak positive group (P=0.069). The logistic univariate analysis did not find high risk factors of distant lymph node metastasis (all P>0.05). Logistic multivariate analysis found that only depth of invasion was a risk factor of lymph node metastasis in limited PESCC (P=0.002).

CONCLUSIONSEsophagus small cell carcinomas sometimes have early lymph node metastases in many sites and distant range. The middle thoracic PESCCs tend to have extensive metastasis quite common in the upper mediastinal lymph nodes. Lower mediastinal and abdominal lymph node metastases are often seen in lower thoracic PESCCs. The depth of invasion and tumor length are main factors influencing mediastinal lymph node metastasis. The depth of invasion is an independent risk factor for lymph node metastasis.

Abdominal Cavity ; Carcinoma, Small Cell ; pathology ; secondary ; Esophageal Neoplasms ; pathology ; Humans ; Lymph Nodes ; pathology ; Lymphatic Metastasis ; Mediastinum ; Multivariate Analysis ; Neoplasm Invasiveness ; Risk Factors