Javed Akhtar

Retraction Note: STMN-1 is a potential marker of lymph node metastasis in distal esophageal adenocarcinomas and silencing its expression can reverse malignant phenotype of tumor cells

BackgroundDistal esophageal adenocarcinoma is a highly aggressive neoplasm. Despite advances in diagnosis and therapy, the prognosis is still poor. Stathmin (STMN-1) is a ubiquitously expressed microtubule destabilizing phosphoprotein. It promotes the disassembly of microtubules and prevents assembly. STMN-1 can cause uncontrolled cell proliferation when mutated and not functioning properly. Recently, found to be overexpressed in many types of human cancers. However, its clinical significance remains elusive in distal esophageal adenocarcinoma. Here, we reported for the first time that STMN-1 is highly overexpressed in adenocarcinomas of the distal esophagus and strongly associated with lymph node metastasis.MethodsSTMN-1 expression in 63 cases of distal esophageal adenocarcinoma was analyzed by immunoblotting, while expression in esophageal adenocarcinoma cells was determined by immunocytochemistry, immunofluorescence, qRT-PCR and western blotting. Lentivirus-mediated RNAi was employed to knock-down STMN-1 expression in Human esophageal adenocarcinoma cells. The relationship between STMN-1 expression and lymph node metastasis in distal esophageal adenocarcinoma was determined by univariate and multivariate analyses.ResultsSTMN-1 was detected in 31 (49.21%) of the 63 cases. STMN-1 was highly overexpressed in specimens with lymph node metastasis pN (+), but its expression was almost undetected in pN (−) status. Multivarian regression analysis demonstrated that STMN-1 overexpression is an independent factor for lymph node metastasis in distal esophageal adenocarcinoma. STMN-1 shRNA effectively reduced STMN-1 expression in esophageal adenocarcinoma cells (P < 0.05), which significantly suppressed proliferation (P < 0.05), increased migration (P < 0.05) and invasion ability (P < 0.05) and G1 phase arrest (P < 0.05) which lead to induction of apoptosis in esophageal adenocarcinoma cells in vitro. To verify the in vitro data, we conducted in vivo tumor xenograft studies. Esophageal adenocarcinoma cells stably transfected with STMN-1 shRNA significantly reduced tumor xenografts volume in vivo.ConclusionsSTMN-1 overexpression is associated with lymph node metastasis and increase malignancy in distal esophageal adenocarcinoma. In vivo and in vitro laboratory findings, suggests that STMN-1 may be a suitable target for future therapeutic strategies in distal esophageal adenocarcinoma.

Effectiveness of local injection of lentivirus-delivered stathmin1 and stathmin1 shRNA in human gastric cancer xenograft mouse

We have reported previously that RNA interference targeting stathmin1 (STMN1) gene in human gastric cancer cells inhibits proliferation in vitro and tumor growth in vivo. Based on these observations, in the present study, the possibility that local injection of lentivirus‐delivered stathmin shRNA would induce regression of the established human gastric cancer xenograft in animal model was investigated.

Anti-STMN1 therapy improves sensitivity to antimicrotubule drugs in esophageal squamous cell carcinoma

Stathmin (STMN1) regulates microtubule dynamics by promoting depolymerization of microtubules and/or preventing polymerization of tubulin heterodimers. Several studies have shown that overexpression of STMN1 has been linked to chemoresistance of paclitaxel and vinblastine in tumor cells. This study aimed to investigate the effects of STMN1 silencing on chemosensitivities of paclitaxel or vinblastine in esophageal squamous cell carcinoma (ESCC). Immunocytochemistry and immunofluorescence assays showed that STMN1 gene was highly expressed in Eca109 and TE-1 cells. We demonstrated that lentiviral-mediated STMN1 short hairpin RNA (shRNA) specifically and efficiently downregulated STMN1 expression in Eca109 and TE-1 cells. The sensitivity of STMN1-silencing shRNA-transfected Eca109 and TE-1 cells increased 191.4- and 179.3-fold to paclitaxel, and 21.3- and 28.4-fold to vincristine, respectively. Flow cytometry and mitotic index assays showed that knockdown of STMN1 in Eca109 and TE-1 cells led to cell cycle arrest in G2/M phase. After treatment with paclitaxel or vincristine, STMN1-silencing shRNA-transfected Eca109 and TE-1 cells were more likely to enter G2 but less likely to enter mitosis than control cells. Therefore, these data suggests that silencing STMN1 gene could increase sensitivity of ESCC to paclitaxel and vincristine through G2/M phase block.

Stathmin overexpression identifies high risk for lymphatic metastatic recurrence in pN0 esophageal squamous cell carcinoma patients.

Common patterns of the operative failure after Ivor‐Lewis esophagectomy in esophageal squamous cell carcinoma (ESCC) patients are locoregional lymph node metastasis. It is clinically significant to investigate the biological markers to predict the subset of patients who are at higher risk of lymphatic metastatic recurrence. Our research aimed to investigate the association between the Stathmin (STMN‐1) gene expression and lymphatic metastatic recurrence in pN0 ESCC patients after surgery.

AngiotensinII induces HuR shuttling by post-transcriptional regulated CyclinD1 in human mesangial cells

Abstract Abnormal proliferation of human mesangial cells was the earliest pathological character in chronic kidney disease and linked to the accumulation of extracellular matrix and glomerular sclerosis. Multifunctional Angiotensin (AngII) had been emerged as a key player in initiation and progression of fibrogenic processes in kidney. In mesangial cells, treatment with the proliferation stimulus AngII triggered the escalated cyclinD1 expression, where its association with HuR increased dramatically. In our study, it was demonstrated that both in vivo and in vitro HuR redistribution in dysregulated mesangial cell proliferation accompanied by an abundant cyclinD1 expression following the AngII treatment. ActinomycinD experiments revealed that AngII stabilized cyclinD1 mRNA in human mesangial cells via HuR. Furthermore, employing the RIP-Chip assay yielded cyclinD1 mRNA with a higher affinity to HuR in mesangial cells induced by AngII compared with the normal ones in vitro study. Analysis of a cyclinD1 mRNA directly implicated HuR in regulating cyclinD1 production: cyclinD1 translation increased in HuR-shuttling cells induced by AngII and declined in cells in which HuR levels were lowered by RNA interference. We proposed that the release of HuR-bound mRNAs via an AngII–cyclinD1–HuR regulatory axis was implicated in the evolution of proliferative kidney diseases, providing us a novel therapeutic strategy to treat glomerular disease.

Alteration of runt-related transcription factor 3 gene expression and biologic behavior of esophageal carcinoma TE-1 cells after 5-azacytidine intervention.

5-Azacytidine (5-azaC) was originally identified as an anticancer drug (NSC102876) which can cause hypomethylation of tumor suppressor genes. To assess its effects on runt-related transcription factor 3 (RUNX3), expression levels and the promoter methylation status of the RUNX3 gene were assessed. We also investigated alteration of biologic behavior of esophageal carcinoma TE-1 cells. MTT assays showed 5-azaC inhibited the proliferation of TE-1 cells in a time and dose-dependent way. Although other genes could be demethylated after 5-azaC intervention, we focused on RUNX3 gene in this study. The expression level of RUNX3 mRNA increased significantly in TE-1 cells after treatment with 5-azaC at hypotoxic levels. RT-PCR showed 5-azaC at 50 μM had the highest RUNX3-induction activity. Methylation-specific PCR indicated that 5-azaC induced RUNX3 expression through demethylation. Migration and invasion of TE-1 cells were inhibited by 5-azaC, along with growth of Eca109 xenografts in nude mice. In conclusion, we demonstrate that the RUNX3 gene can be reactivated by the demethylation reagent 5-azaC, which inhibits the proliferation, migration and invasion of esophageal carcinoma TE-1 cells.

Lentiviral vector-mediated survivin shRNA delivery in gastric cancer cell lines significantly inhibits cell proliferation and tumor growth

It has been well documented that survivin has multiple functions including cytoprotection, inhibition of cell death, and cell cycle regulation, particularly at the mitotic stage of the cell cycle, all of which favor cancer survival. Its expression in normal tissue is developmentally regulated, and any type of deregulation in survivin expression favors cancer survival. Gastric cancer is one of the most common malignancies and the second most common cause of cancer-related mortality worldwide. The molecular mechanisms involved in the transformation and progression of gastric cancer remain unclear. In the present study, we investigated the effect of lentiviral vector-mediated survivin shRNA delivery in gastric cancer cell lines. Lentiviral-mediated survivin shRNA was used to knock down survivin expression in gastric cancer cell lines SGC-7901, MGC-803 and MKN-28. The Τranswell chemotaxis and the CCK-8 assays were used to assess the migration and proliferation of the tumor cells, respectively. TUNEL assay was used to detect apoptosis. Quantitative real-time PCR and western blot analysis were used to quantify mRNA and protein levels, respectively. Our results demonstrated that lentiviral-mediated RNAi markedly suppressed the survivin expression in all three gastric cancer cell lines. Significant decrease in survivin mRNA and protein expression were detected in the gastric cancer cell lines stably transfected with the lentiviral survivin shRNA vector, and knockdown of survivin also significantly inhibited the proliferation and migration in the gastric cancer cells and tumorigenicity in a xenograft animal model. Our results indicated that aberrant high cytoplasmic survivin expression in gastric cancer cells is associated with increased proliferation index and tumor growth. In conclusion, our results suggest that lentiviral-mediated gene therapy has the potential to be developed into a novel therapeutic strategy for the treatment of gastric cancer.

High phosphate feeding induced arterial medial calcification in uremic rats: Roles of Lanthanum carbonate on protecting vasculature

AIMS High cardiovascular mortality in patients with end-stage renal disease is closely associated with arterial medial calcification (AMC) caused by hyperphosphatemia, the mechanism of which associated hormones (FGF-23, klotho) and osteochondrogenic events is unclear. We examined the effect of Lanthanum carbonate on AMC via regulating the abnormalities in phosphorus metabolism of uremic rats. MAIN METHODS 45 healthy SD rats were randomly divided into 3 groups: Normal group (n=15), CRF group (n=15), CRF diet supplemented with 2% La (n=15). AMC in great arteries were evaluated by VonKossa. Osteochondrogenic specific genes were analyzed by Immunohistochemistry and qRT-PCR. Serum FGF-23 and klotho levels were detected by ELISA kit. KEY FINDINGS Serum phosphate was markedly increased in CRF group (6.94 ± 0.97 mmol/L) and 2%La group (5.12 ± 0.84 mmol/L) at week 4, while the latter became hypophosphatemic (2.92 ± 0.73 mmol/L vs CRF group, p<0.01) at week 10. Inhibitory effect of 2%La on development of AMC was reflected by downregulated Runx2, Osterix, BSP, Osteocalcin and collagenII and a reduction of FGF-23 at week 4(vs CRF group, p<0.01) but not week 10. SIGNIFICANCE Beneficial effects of Lanthanum carbonate on progression of AMC in CRF could be mainly due to the decreased phosphate retention and FGF-23 in early stage and likewise a reduction of bone-associated proteins via osteochondrogenic pathway. Lanthanum carbonate has no effect on soluble klotho and serum FGF-23 in late stage of CRF.