Metastasis associated protein 1 correlates with Hypoxia inducible-factor 1 alpha expression and lymphangiogenesis in esophageal cancer

Prognostic significance of preoperative anaemia on occurrence of regional metastases and second primary tumours in patients with early-stage oral squamous cell carcinoma

The aim of this study was to evaluate the effect of preoperative anaemia on the risk of occurrence of regional metastases and second primary tumours in patients with early-stage (cT1-T2N0M0) oral squamous cell carcinoma (OSCC) after primary surgical treatment. Consecutive patients with OSCC who were referred to University Hospital Dubrava and University Clinical Centre of Kosovo between January 1, 2000 and December 31, 2010, and who met the following criteria, were included: adult> 18 years of age; verified cT1-T2N0M0 stage; available data on clinical and laboratory work-up allowing the assessment of demographics, lifestyle/habits, anaemia, and comorbidities. The inclusion time-frame allowed a maximum potential censored observation of 15 years and minimum censored observation of 5 years (patients treated by the end of 2010). Microcytic anaemia was significantly associated with a higher risk of regional metastases (60% vs 40%, P = 0.030), with an odds ratio of 3.65 (95% confidence interval 1.33-9.97, P = 0.028). Alcohol consumption was independently associated with an increased risk of second primary tumour, with an odds ratio of 2.79 (95% confidence interval 1.32-5.87, P = 0.007). In patients with OSCC, microcytic anaemia was found to be an independent predictor of regional metastases, and alcohol consumption an independent predictor of second primary tumour.

Stathmin1 promotes lymph node metastasis in hypopharyngeal squamous cell carcinoma via regulation of HIF‑1α/VEGF‑A axis and MTA1 expression

Extensive neck lymph node metastasis (LNM) is an important clinical feature of hypopharyngeal squamous cell carcinoma (HSCC). Stathmin1 (STMN1) is closely associated with LNM in numerous human cancers. In the present study, the association between STMN1 and neck LNM in HSCC and the underlying molecular mechanisms were explored. First, postoperative samples of HSCC were screened and the association between STMN1 and neck LNM in HSCC was analyzed. Then, cell functional experiments were performed to assess the potential of STMN1 to promote invasion and migration. Subsequently, the potential target genes and pathways of STMN1 were predicted using bioinformatics analysis. Finally, the obtained target genes and pathways of STMN1 were validated by reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses to confirm the potential mechanisms by which STMN1 promotes LNM in HSCC. As a result, a total of 117 postoperative samples of HSCC were screened, and STMN1 was proven to be associated with neck LNM in HSCC. Further, cell functional experiments established that high expression of STMN1 could actually promote FaDu cell invasion and metastasis. Bioinformatics analysis revealed that high expression of STMN1 was associated with the activation of hypoxia inducible factor-1alpha (HIF-1α) pathway and increased expression of metastasis-associated protein 1 (MTA1). Finally, RT-qPCR and western blot analyses confirmed that STMN1 promotes the expression levels of HIF-1α/vascular endothelial growth factor (VEGF)-A and MTA1 in FaDu cell lines. In conclusion, it was found that high expression of STMN1 promoted neck LNM in HSCC and the potential mechanisms may be via regulation of the HIF-1α/VEGF-A axis and MTA1 expression.

Cytoplasmic translocation of MTA1 coregulator promotes de-repression of SGK1 transcription in hypoxic cancer cells

Chromatin remodeling factor metastatic tumor protein 1 (MTA1), one of the most upregulated oncogene in human cancer, has an important role in gene expression, cell survival and promoting hypoxic response. Successful cancer progression is dependent on the ability of cells to utilize its survival pathways for adapting to hypoxic microenvironment. Although MTA1 is a stress-responsive gene, but whether hypoxia modulates its function and its role in engaging other core stress-responsive survival pathway(s) remains unknown. Here we have discovered that MTA1 is a novel corepressor of serum and glucocorticoid-inducible kinase 1 (SGK1). Surprisingly, this regulatory corepressive function of MTA1 is lost under hypoxia, allowing upregulation of SGK1 expression and engaging the MTA1-SGK1 axis for the benefit of the cell survival. The underlying mechanism of the noticed stimulation of SGK1 expression by hypoxia includes de-repression of SGK1 transcription because of hypoxia-triggered nucleus-to-cytoplasmic translocation of MTA1. In addition, the newly recognized cytoplasmic translocation of MTA1 was dependent on the chaperoning function of heat shock protein 90 (HSP90) and co-accompanied by the formation of MTA1, HSP90 and HIF1α complex under hypoxic condition but not under normoxic condition. Hypoxia-triggered redistribution of MTA1, SGK1 upregulation and cell survival functions were compromised by a pharmacological SGK1 inhibitor. In summary, for the first time, we report MTA1 regulation of SGK1 expression, hypoxia-dependent MTA1 translocation to the cytoplasm and de-repression of SGK1 transcription. These findings illustrate how cancer cells utilize a chromatin remodeling factor to engage a core survival pathway to support its cancerous phenotypes, and reveal new facets of MTA1-SGK1 axis by a physiologic signal in cancer progression.