LncRNA CCAT1 knockdown suppresses tongue squamous cell carcinoma progression by inhibiting the ubiquitination of PHLPP2.

Tongue squamous cell carcinoma (TSCC) is prevailing malignancy in the oral and maxillofacial region, characterized by its high frequency. LncRNA CCAT1 can promote tumorigenesis and progression in many cancers. Here, we investigated the regulatory mechanism by which CCAT1 influences growth and metastasis of TSCC. Levels of CCAT1, WTAP, TRIM46, PHLPP2, AKT, p-AKT, and Ki67 in TSCC tissues and cells were assessed utilizing qRT-PCR, Western blot and IHC. Cell proliferation, migration, and invasion were evaluated utilizing CCK8, colony formation, wound healing and transwell assays. Subcellular localization of CCAT1 was detected utilizing FISH assay. m6A level of CCAT1 was assessed using MeRIP. RNA immunoprecipitation (RIP), Co-immunoprecipitation (Co-IP) and RNA pull down elucidated binding relationship between molecules. Nude mouse tumorigenesis experiments were used to verify the TSCC regulatory function of CCAT1 in vivo. Metastatic pulmonary nodules were observed utilizing hematoxylin and eosin (HE) staining. CCAT1 silencing repressed TSCC cell proliferation, migration and invasion. Expression of CCAT1 was enhanced through N6-methyladenosine (m6A) modification of its RNA, facilitated by WTAP. Moreover, IGF2BP1 up-regulated CCAT1 expression by stabilizing its RNA transcript. CCAT1 bond to PHLPP2, inducing its ubiquitination and activating AKT signaling. CCAT1 mediated the ubiquitination and degradation of PHLPP2 by TRIM46, thereby promoting TSCC growth and metastasis. CCAT1/TRIM46/PHLPP2 axis regulated proliferation and invasion of TSCC cells, implying that CCAT1 would be a novel therapeutic target for TSCC patients.

Evaluation of Copper Levels in Dental Calculus of OSF Patients with Chewing Dried Areca-Nut Quids in Hunan Province of Mainland China.

Dental calculus is a potential material that can be used for assessing chronic exposure to trace heavy metals in oral cavity as it is a long-term reservoir. The aim of this study was to investigate the correlation between dental calculus copper levels and risk of oral submucous fibrosis (OSF) due to chewing dried areca-nut quids in Mainland China. This study included 34 OSF (grade 1) sufferers with dried areca-nut quids chewing as the patient group and 23 healthy individuals without areca-nut chewing as the control group. The dental calculus sample was obtained from all 57 participants and evaluated by inductively coupled plasma mass spectrometry (ICP-MS) for dental calculus level of copper. This work revealed that the mean copper level of dental calculus was significantly higher in OSF (grade 1) sufferers with areca-nut chewing than those in healthy individuals without areca-nut chewing (p < 0.001). This work provided an evidence to support that there may be a positive correlation between elevated levels of copper in dental calculus caused by chewing dried areca-nut quids and an increased risk of developing OSF in Mainland China.

Dirhodium(II)-Catalyzed (3 + 2) Cycloaddition of the N-Arylaminocyclopropane with Alkene Derivatives.

Several (3 + 2) cycloaddition reactions catalyzed by dirhodium(II) complexes between N-arylaminocyclopropane and alkenes derivative have been developed. Preliminary mechanism studies suggest that dirhodium(II) complexes may decrease the bond-dissociation energy (BDE) of the N-H bond of N-arylaminocyclopropanes for N-H bond activation, thus facilitating the formation of N-centered radicals by loss of a hydrogen radical.