This study aims to explore the mechanism of the signal transmission between oral squamous cell carcinoma (OSCC) and unpolarized stromal immune macrophages mediated by OSCC-derived exosomes (OSCC-Exo). Polarization of macrophages was found by detection of the level of protein markers or specific components for M1 subtype or M2 subtype macrophages, respectively. Exosomes extracted from two OSCC cell lines, which might have been transfected with micro-RNA (miR)-29a-3p inhibitor or mimic, were cocultured with macrophages to ensure the effect of exosome-enclosed miR-29a-3p on the polarization of macrophages. miR-29a-3p is highly expressed, suppressor of cytokine signaling 1 (SOCS1) is low expressed and phosphorylated signal transduction and transcriptional activator 6 (p-STAT6) is highly expressed in OSCC tissues. Upregulation of miR-29a-3p is observed in OSCC-derived exosomes. When cocultured, OSCC-derived exosomes promote M2 subtype macrophage polarization and the medium of the coculture promotes the proliferation and invasion of SCC-9 and CAL-27 cells. After interfered silencing miR-29a-3p of OSCCs, SCC-9- and CAL-27 cell-derived exosomes inhibit M2 subtype macrophage polarization. On the other hand, cellular highly expressed miR-29a-3p of macrophages enhances M2 subtype macrophage polarization. Moreover, such macrophages promote the proliferation and invasion of SCC-9 and CAL-27. SOCS1 is a direct target for miR-29a-3p and could be negatively regulated by miR-29a-3p. Moreover, SOCS1 overexpression reverses the activity of SOCS1/STAT6 signals of macrophages and cell proliferation and invasion of OSCCs induced by miR-29a-3p overexpression. Also, overexpressed SOCS1 in macrophages counteracts the impact of OSCC-derived exosomes in M2 subtype macrophage polarization. Exosome-enclosed miR-29a-3p promotes tumor growth in nude mice with xenograft. OSCC-derived exosomes promote M2 subtype macrophage polarization mediated by exosome-enclosed miR-29a-3p, and the mechanism by miR-29a-3p is the activity of SOCS1/STAT6 signals in macrophages.

This study aimed to elucidate how microRNA27a-3p (miR-27a-3p) modulates the Wnt/β-catenin signaling pathway to promote the epithelial-mesenchymal transition (EMT) in oral squamous carcinoma stem cells (OSCSCs) by targeting secreted frizzled-related protein 1 (SFRP1). Flow cytometry was used to sort OSCSCs from the SCC-9 and Tca8113 cell lines. The OSCSCs were randomly assigned into the miR-27a-3p inhibitors group, the miR-27a-3p inhibitors-NC group, the si-SFRP1 group, the si-SFRP1 + miR-27a-3p inhibitors group and the blank group. A luciferase reporter, immunofluorescence and Transwell assays were performed to detect luciferase activity, SFRP1, and cell migration and invasion, respectively. The mRNA expression of miR-27a-3p, SFRP1 and EMT markers (E-cadherin, N-cadherin, vimentin and ZEB1) were detected using qRT-PCR. The protein expression of SFRP1, EMT markers and the proteins of the Wnt/β-catenin signaling pathway was detected by Western blotting. OSCSCs showed up-regulated miR-27a-3p, Wnt/β-catenin signaling pathway-related proteins, vimentin, N-cadherin and ZEB1 and down-regulated SFRP1 and E-cadherin. MiR-27a-3p targeted SFRP1. Down-regulated miR-27a-3p resulted in increased E-cadherin and SFRP1 but decreased vimentin, N-cadherin, ZEB1, the Wnt/β-catenin signaling pathway-related proteins, and invasive and migratory cells. Silenced SFRP1 reversed this effect. We found that miR-27a-3p modulated the Wnt/β-catenin signaling pathway to promote EMT in OSCSCs by down-regulating SFRP1.

In this study, we investigated the effects of microRNA-542-3p (miR-542-3p) on ILK/TGF-β1/Smad2/3 signaling and oral squamous cell carcinoma (OSCC) progression. Levels of miR-542-3p were lower in OSCC tissues (n=108) than adjacent normal tissues, whereas levels of ILK, TGF-β1 and Smad2/3 were higher. Patients with undifferentiated tumors, advanced TNM stage and lymph node metastasis showed low miR-542-3p levels. This was accompanied by high ILK expression and poor survival. Dual luciferase reporter assays of SCC-9 cells showed that miR-542-3p inhibited ILK gene expression by binding to its 3’UTR at 233-240 bp. SCC-9 cells transfected with miR-542-3p mimics exhibited elevated miR-542-3p and decreased ILK, TGF-β1 and Smad2/3 expression. They also showed reduced self-renewal (fewer CD44+ cells and tumor-spheres), invasiveness, migration, proliferation and survival. Conversely, miR-542-3p inhibitors promoted increased self-renewal (more CD44+ cells and tumor-spheres), invasiveness, migration, proliferation and survival. In xenograft experiments with nude mice, SCC-9 cells transfected with miR-542-3p mimics or siRNA-ILK yielded tumors with smaller volumes and weights than control tumors. These results demonstrate that miR-542-3p is a tumor suppressor that inhibits ILK/TGF-β1/Smad2/3 signaling, thereby inhibiting OSCC progression.

BackgroundA disintegrin and metalloprotease 12 (ADAM12) is a member of the multidomain protein family, but the mechanisms by which it affects prognosis and immune cell infiltration in patients with colon adenocarcinoma (COAD) remain unclear. Here, our study aimed to analyze the prognostic value of ADAM12 and investigate the correlation between ADAM12 expression and immune cell infiltration in patients with COAD.MethodsDifferential expression analyses were performed using the Oncomine and UALCAN databases, and prognostic analyses were conducted using PrognoScan, Gene Expression Profiling Interactive Analysis (GEPIA), and Kaplan–Meier Plotter. Then, the cBioPortal database was used to analyze alterations in the ADAM12 gene, and the STRING and Metascape websites were used to conduct Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Additionally, relationships between ADAM12 and the immune microenvironment were evaluated based on the TIMER, GEPIA, and TISIDB databases.ResultsADAM12 was overexpressed in COAD tissues, and higher ADAM12 expression correlated with a worse prognosis for patients with COAD. The gene regulatory network suggested that ADAM12 was mainly enriched in extracellular matrix (ECM) organization, ECM proteoglycans, skeletal system development, and ossification, among other pathways. Moreover, ADAM12 expression significantly correlated with the abundance of CD4+ T cells, B cells, CD8+ T cells, neutrophils, macrophages, dendritic cells, and their markers, as well as lymphocytes, immunomodulators, and chemokines.ConclusionsIn colorectal tumors, ADAM12 may play vital roles in regulating the ECM and the recruitment of immune cells, and we suggest that ADAM12 will become a reliable biomarker for determining response to immunotherapy and the prognosis of patients with COAD.

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Oct4 and Sox2 are pluripotent stem cell factors but the interplay between them in tumorigenesis is unclear. The aim of the present study was to investigate the roles of Oct4 and Sox2 in the reprogramming of oral cancer stem cells. One or both Oct4 and Sox2 were overexpressed in immortalized oral epithelial (hTERT+-OME) cells by lentivirus transduction. In addition, Oct4 and Sox2 proteins in two oral squamous cell carcinoma cell (OSCC) lines (Cal27 and primary cultured OSCC from a T2N2M0 patient) were individually or combinedly knocked down by shRNA. The results showed that the doubly transduced (Oct4+Sox2+) cells could trigger neoplasms in immunodeficient mice after lentivirus transduction, but single transduced (Oct4+ or Sox2+) cells had no tumor formation ability. The knockdown Sox2low and knockdown Oct4lowSox2low cells resulted in decreased tumor size in the immunodeficient mice but the single knockdown Oct4low cancer cells acquired more aggressive xenografts. Our findings suggest that Oct4+Sox2+ cells may be reprogrammed cancer stem cells inducing oral carcinogenesis.

Oral carcinoma (OC) remains one of the most difficult malignancies to cure. selenium (Se) is an essential trace mineral for human and animals, but high concentrations of Se induce apoptosis and oxidative effects. Although cell apoptosis has been evidenced as a critical mechanism mediating the anticancer activity of Se, the underlying molecular mechanisms remain elusive. To explore the role of Se in rat OC, we examined the weather the oxidative stress-mediated apoptotic pathway induced by Se was involved in the development of OC. In this study, we successfully constructed the OC rat model by 4-Nitroquinoline-1-oxide (4-NQO) exposure which reflected from histopathological observations. Se-induced the productions of methane dicarboxylic aldehyde (MDA) and reactive oxygen species (ROS), which was accompanied by the inhibition of superoxide dismutase (SOD) both in vivo and vitro. The anti-apoptotic gene (Bcl-2) was down-regulated and pro-apoptosis members (Bax, Bak, Cyt-c, caspase9 and caspase3) were up-regulated by Se in OC cells. Meanwhile, we also found that Se could strongly inhibited the cell proliferation of OC lines in vitro. These results suggested that excessive Se could effectively cause oxidative stress and induce apoptosis in OC cells, as a result the OC was also inhibited to some extent. Therefore, the information presented in this study is believed to be helpful in supplementing data for further therapy of OC.

Arca subcrenata is documented in the literature of marine Traditional Chinese Medicine. Polypeptide fraction from A. subcrenata, coded as P2, was demonstrated to possess significant antitumor activity in our previous study. However, the underlying mechanism remains undefined. The present study was carried out to investigate the underlying antitumor mechanism of P2 in human cervical cancer HeLa cells by MTT, FCM, LSCM, and western blot assays. The results revealed that P2 significantly induced apoptosis of HeLa cells in a concentration- and time-dependent manner. High level of ROS was provoked by P2, which was in turn responsible for induction of apoptosis through activation of intrinsic mitochondrial pathway and JNK1/2, p38 MAPK pathways, as well as inhibition of ERK1/2 pathway, as evidenced by the abrogation of P2's effect on HeLa cells preincubated with the ROS scavenger NAC. P2 also was observed to display significant effect on G2/M phase arrest by downregulating the expression of cyclin B1/cdc2 complex and upregulating the expression of p21. These findings demonstrate that P2 induces apoptosis and G2/M phase arrest in HeLa cells through ROS-mediated MAPKs pathways, suggesting that P2 would be worth investigating as a promising agent within the scope of marine drugs for treatment of cervical cancer.