With the development of functional genomics studies, a mass of long non‐coding RNAs (LncRNA) were discovered from the human genome. Long non‐coding RNAs serve as pivotal regulators of genes that are able to generate LncRNA–binding protein complexes to modulate a great number of genes. Recently, the LncRNA urothelial carcinoma‐associated 1 (UCA1) has been revealed to be dysregulated, which plays a critical role in the development of a few cancers. However, the role of the biology and clinical significance of UCA1 in the tumorigenesis of oral squamous cell carcinoma (OSCC) remain unknown. We found that UCA1 expression levels were upregulated aberrantly in tongue squamous cell carcinoma tissues and associated with lymph node metastasis and TNM stage. We explored the expression, function, and molecular mechanism of LncRNA UCA1 in OSCC. In the present work, we revealed that UCA1 silencing suppressed proliferation and metastasis and induced apoptosis of OSCC cell lines in vitro and in vivo, which might be related to the activation level of the WNT/β‐catenin signaling pathway. Our research results emphasize the pivotal role of UCA1 in the oncogenesis of OSCC and reveal a novel LncRNA UCA1–β‐catenin–WNT signaling pathway regulatory network that could contribute to our understanding in the pathogenesis of OSCC and assist in the discovery of a viable LncRNA‐directed diagnostic and therapeutic strategy for this fatal disease.

BackgroundWe previously described several abnormally expressed long non-coding RNA (lncRNA) in tong squamous cell carcinomas (TSCCs) that might be associated with tumor progression. In the present study, we aimed to investigate the role of abnormally expressed metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) lncRNA in the metastatic potential of TSCC cells and its molecular mechanisms.MethodsExpression levels of MALAT-1 lncRNA were examined via quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in 127 TSCC samples as well as paired adjacent normal tissues and lymph node metastases (if exist). Lentiviral vectors expressing short hairpin RNA (shRNA) were used to knock down the expression of MALAT1 gene in two TSCC cell lines (CAL27 and SCC-25) with relatively higher MALAT-1 expression. Proliferational ability of the TSCC cells was analyzed using water soluble tetrazolium-1 (WST-1) assay. Metastatic abilities of TSCC cells were estimated in-vitro and in-vivo. We also performed a microarray-based screen to identify the genes influenced by MALAT-1 alteration, which were validated by real-time PCR analysis.ResultsExpression of MALAT-1 lncRNA was enhanced in TSCCs, especially in those with lymph node metastasis (LNM). Knockdown (KD) of MALAT-1 lncRNA in TSCC cells led to impaired migration and proliferation ability in-vitro and fewer metastases in-vivo. DNA microarray analysis showed that several members of small proline rich proteins (SPRR) were up-regulated by KD of MALAT-1 lncRNA in TSCC cells. SPRR2A over-expression could impair distant metastasis of TSCC cells in-vivo.ConclusionEnhanced expression of MALAT-1 is associated with the growth and metastatic potential of TSCCs. Knock down of MALAT-1 in TSCCs leads to the up-regulation of certain SPRR proteins, which influenced the distant metastasis of TSCC cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2735-x) contains supplementary material, which is available to authorized users.

Basaloid squamous cell carcinoma (BSCC) is a rare, but distinct histologic variant of squamous cell carcinoma in the head and neck region. It is considered to have a poor prognosis due to its aggressive behavior and tendency to metastasize. The usual sites of BSCC are the floor of the mouth, hypopharynx and base of the tongue, and according to the English-language literature its presentation in the gingiva is somewhat uncommon. In the current report, the unusual case of a 40-year-old male is presented; the patient exhibited a painless irregular mass in the maxillary gingiva, which infiltrated the maxillary sinus, as observed by computed tomography. Hematoxylin and eosin-stained sections revealed a diagnosis of BSCC with typical central necrosis in the cancer nests, which contained basaloid and squamous cells. Immunohistochemistry revealed that p63 was weakly positive, high molecular weight cytokeratin (CK) was focally positive, and S-100, CK7, CK14 and vimentin were negative. It must be noted that histopathology results may be incorrectly interpreted as adenoid cystic carcinoma, undifferentiated carcinoma and basal cell adenocarcinoma.

The salivary gland benign and malignant tumors were more common in pleomorphic adenoma and adenoid cystic carcinoma, most occurred in the parotid gland. The minor gland tumors are lower than other parts of China. The incidence of parotid gland tumors is not related to the use of cell phones.