MYCT1 inhibits hematopoiesis in diffuse large B-cell lymphoma by suppressing RUNX1 transcription.

BACKGROUND: The abnormality of chromosomal karyotype is one factor causing poor prognosis of lymphoma. In the analysis of abnormal karyotype of lymphoma patients, three smallest overlap regions were found, in which MYCT1 was located. MYCT1 is the first tumor suppressor gene cloned by our research team, but its studies relating to the occurrence and development of lymphoma have not been reported. METHODS: R banding analyses were employed to screen the abnormality of chromosomal karyotype in clinical specimen and MYCT1 over-expression cell lines. FISH was to monitor MYCT1 copy number aberration. RT-PCR and Western blot were to detect the mRNA and protein levels of the MYCT1 and RUNX1 genes, respectively. The MYCT1 and RUNX1 protein levels in clinical specimen were evaluated by immunohistochemical DAB staining. The interaction between MYCT1 and MAX proteins was identified via Co-IP and IF. The binding of MAX on the promoter of the RUNX1 gene was detected by ChIP and Dual-luciferase reporter assay, respectively. Flow cytometry and CCK-8 assay were to explore the effects of MYCT1 and RUNX1 on the cell cycle and proliferation, respectively. RESULTS: MYCT1 was located in one of three smallest overlap regions of diffuse large B-cell lymphoma, it altered chromosomal instability of diffuse large B-cell lymphoma cells. MYCT1 negatively correlated with RUNX1 in lymphoma tissues of the patients. MAX directly promoted the RUNX1 gene transcription by binding to its promoter region. MYCT1 may represses RUNX1 transcription by binding MAX in diffuse large B-cell lymphoma cells. MYCT1 binding to MAX probably suppressed RUNX1 transcription, leading to the inhibition of proliferation and cell cycle of the diffuse large B-cell lymphoma cells. CONCLUSION: This study finds that there is a MYCT1-MAX-RUNX1 signaling pathway in diffuse large B-cell lymphoma. And the study provides clues and basis for the in-depth studies of MYCT1 in the diagnosis, treatment and prognosis of lymphoma.

DOCK8 Serves as a Prognostic Biomarker and Is Related to Immune Infiltration in Patients With HPV Positive Head and Neck Squamous Cell Carcinoma.

PURPOSE: Dedicator of cytokinesis 8 (DOCK8) was reported to have a vital link to immunoregulation. However, the mechanisms by which it drives immune infiltration in cancer remain uncertain. We tried to assess the role of DOCK8 in patients with cancer, especially human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC). METHODS: Data on the expression and survival of DOCK8 in patients with various cancers were analyzed using the Oncomine and TIMER databases. The TIMER database assessed the relationship of DOCK8 with immune infiltration levels and various markers of multiple immune cells. Gene set enrichment analysis revealed tumor-associated biological processes related to DOCK8. ENCODE database was used to explore relevant transcription factors of DOCK8, and a PPI network was constructed using GENEMINIA. The expression and survival role of DOCK8 was confirmed in patients from independent GEO datasets. RESULTS: We determined that DOCK8 expression was upregulated or downregulated in various cancers unlike in healthy tissues. A high expression of DOCK8 was significantly correlated with a favorable prognosis in HPV-positive HNSCC and lung adenocarcinoma (LUAD). Furthermore, multivariate Cox regression analysis revealed that DOCK8 was an independent prognostic factor of HPV-positive HNSCC. Additionally, elevated DOCK8 expression was positively correlated with multiple immune cell infiltration levels and immune marker expression associated with particular immune cell subsets. Also, 14 pathways involved in immune activities and carcinogenesis, 22 potential TFs, and co-expression proteins of DOCK8 indicated DOCK8 to be related to tumor-associated biological processes. Ultimately, we verified that DOCK8 is upregulated and confers a favorable overall survival and progression-free survival status in patients with HPV-positive HNSCC. CONCLUSION: These results elucidate that high expression of DOCK8 indicates a favorable prognosis in patients with HPV-positive HNSCC as well as increased microenvironmental immune infiltration levels. It would provide new insights into the prognosis predicting and clinical regimen decision making in patients with HPV-positive HNSCC.

MicroRNA-144 Regulates Cardiomyocyte Proliferation and Apoptosis by Targeting TBX1 through the JAK2/STAT1 Pathway.

It is currently believed that the TBX1 gene is one of the core genes of congenital heart disease (CHD). However, there are few studies on the abnormal regulation of TBX1 gene expression. The purpose of this work was to investigate the role of miR-144 and TBX1 in cardiac development by studying the regulatory relationship and mechanism of miR-144 on TBX1/JAK2/STAT1 in cardiomyocytes. Cell proliferation was detected by MTT and clone formation assay and cell cycle and apoptosis by flow cytometry. The levels of miR-144 and TBX1 in H9c2 cells were assessed by qRT-PCR. Dual luciferase reporter assay was used to validate the direct targeting of TBX1 with miR-144. The protein expression levels of TBX1 and its downstream proteins were measured by Western blot analysis. miR-144 inhibited H9c2 cell proliferation by arresting cells in G1 phase. Furthermore, miR-144 induced H9c2 cell apoptosis and activated the JAK2/STAT1 signaling pathway. Bioinformatic predictions and luciferase reporter assay showed that miR-144 directly targets TBX1. Co-overexpression of miR-144 and TBX1 upregulated cell proliferation by accelerating G1 to S phase transition and downregulated cell apoptosis through inhibiting the JAK2/STAT1 signaling pathway. miR-144 acts as a proliferation inhibitor in cardiomyocytes via the TBX1/JAK2/STAT1 axis and is therefore a potential novel therapeutic target for CHD treatment.

Oncogenic miR-23a in Pancreatic Ductal Adenocarcinogenesis Via Inhibiting APAF1.

BACKGROUND: miR-23a, which participates in invasion of pancreatic ductal adenocarcinoma cells into the mesothelial barrier, is a critical regulator in many cancers. It, however, is still unknown whether miR-23a regulates pancreatic cell proliferation and apoptosis or not. AIMS: We sought to investigate the role of miR-23a in regulation of pancreatic cell proliferation and apoptosis. METHODS: miRNA, mRNA, and protein expressions were determined by qRT-PCR and Western blot, respectively. Dual-luciferase reporter assay was used in detection for binding ability of miR-23a to APAF1. Ectopic miR-23a and APAF 1 were introduced to pancreatic cells, and their roles in proliferation and apoptosis were detected by MTT, colony formation, and apoptosis assays, respectively. RESULTS: Up-regulation of miR-23a and down-regulation of APAF 1 were found in pancreatic ductal cancer, respectively. miR-23a significantly inhibited the luciferase activity by targeting APAF 1 3'UTR. Ectopic miR-23a significantly suppressed the APAF 1 gene expression in pancreatic cancer cells. Similar to siAPAF1, miR-23a significantly promoted pancreatic cancer cell proliferation and repressed apoptosis. Furthermore, miR-23a inhibitor and exogenous APAF 1 could recover the effects. CONCLUSIONS: It is suggested that miR-23a, acting as an oncogenic regulator by directly targeting APAF 1 in pancreatic cancer, is a useful potential biomarker in diagnosis and treatment of pancreatic cancer.

Genetic Effects on Sensorineural Hearing Loss and Evidence-based Treatment for Sensorineural Hearing Loss.

In this article, the mechanism of inheritance behind inherited hearing loss and genetic susceptibility in noise-induced hearing loss are reviewed. Conventional treatments for sensorineural hearing loss (SNHL), i.e. hearing aid and cochlear implant, are effective for some cases, but not without limitations. For example, they provide little benefit for patients of profound SNHL or neural hearing loss, especially when the hearing loss is in poor dynamic range and with low frequency resolution. We emphasize the most recent evidence-based treatment in this field, which includes gene therapy and allotransplantation of stem cells. Their promising results have shown that they might be options of treatment for profound SNHL and neural hearing loss. Although some treatments are still at the experimental stage, it is helpful to be aware of the novel therapies and endeavour to explore the feasibility of their clinical application.

MicroRNA-27a promotes proliferation and suppresses apoptosis by targeting PLK2 in laryngeal carcinoma.

BACKGROUND: miRNA-27a has been confirmed as an important regulator in carcinogenesis and other pathological processes. Whether and how it plays a role in the laryngeal carcinoma is unknown. METHODS: Mature miRNA-27a expression in laryngeal cancer was detected by qRT-PCR. Gain-of-function studies using mature miR-27a were performed to investigate cell proliferation and apoptosis in the Hep2 cells. In silico database analysis and luciferase reporter assay were applied to predict and validate the direct target, respectively. Loss-of-function assays were performed to investigate the functional significance of the miR-27a target gene. qRT-PCR and Western blot were used to evaluate mRNA and protein levels of the target, respectively. RESULTS: miR-27a was significantly up-regulated in the laryngeal tumor tissues compared to the adjacent non-tumor tissues. In silico database analysis result revealed that PLK2 is a potential target of miR-27a. luciferase reporter assay result showed the direct inhibition of miR-27a on PLK2-3'UTR. In the cases with miR-27a up-regulation, PLK2 protein expression level was significantly lower in cancer tissues than that in the adjacent non-tumor tissues, which showed a negative correlation with miR-27a expression level. Both miR-27a and knockdown of PLK2 caused the increase of the cell viability and colony formation and inhibition of the late apoptosis in the Hep2 cell lines. Moreover, miR-27a but not PLK2 also repressed the early apoptosis in the Hep2 cells. Additionally, no alteration of the Hep2 cell cycle induced by miR-27a was detected. CONCLUSIONS: miR-27a acts as an oncogene in laryngeal squamous cell carcinoma through down-regulation of PLK2 and may provide a novel clue into the potential mechanism of LSCC oncogenesis or serve as a useful biomarker in diagnosis and therapy in laryngeal cancer.

Single-cell transcriptomic analyses of tumor microenvironment and molecular reprograming landscape of metastatic laryngeal squamous cell carcinoma.

Laryngeal squamous cell carcinoma (LSCC) is a malignant tumor with a high probability of metastasis. The tumor microenvironment (TME) plays a critical role in cancer metastasis. To gain insights into the TME of LSCC, we conducted single-cell RNA-seq (scRNA-seq) on samples collected from LSCC patients with or without lymphatic metastasis. The stem and immune cell signatures in LSCC suggest their roles in tumor invasion and metastasis. Infiltration of a large number of regulatory T cells, dysplastic plasma cells, and macrophages that are at the early development stage in the cancerous tissue indicates an immunosuppressive state. Abundant neutrophils detected at the cancer margins reflect the inflammatory microenvironment. In addition to dynamic ligand-receptor interactions between the stromal and myeloid cells, the enhanced autophagy in endothelial cells and fibroblasts implies a role in nutrient supply. Taken together, the comprehensive atlas of LSCC obtained allowed us to identify a complex yet unique TME of LSCC, which may help identify potential diagnostic biomarkers and therapeutic targets for LSCC.

MYCT1 in cancer development: Gene structure, regulation, and biological implications for diagnosis and treatment.

Myc target 1 (MYCT1), located at 6q25.2, is a crucial player in cancer development. While widely distributed in cells, its subcellular localization varies across different cancer types. As a novel c-Myc target gene, MYCT1 is subject to regulation by multiple transcription factors. Studies have revealed aberrant expression of MYCT1 in various cancers, impacting pivotal biological processes such as proliferation, apoptosis, migration, genomic instability, and differentiation in cancer cells. Additionally, MYCT1 plays a critical role in modulating tumor angiogenesis and remodeling tumor immune responses within the tumor microenvironment. Despite certain debated functions, MYCT1 undeniably holds significance in cancer development. In this review, we comprehensively examine the relationship between MYCT1 and cancer, encompassing gene structure, regulation of gene expression, gene mutation, and biological function, with the aim of providing valuable insights for cancer diagnosis and treatment.

Small RNA shuffling between murine sperm and their cytoplasmic droplets during epididymal maturation.

Reports that mouse sperm gain small RNAs from the epididymosomes secreted by epididymal epithelial cells and that these "foreign" small RNAs act as an epigenetic information carrier mediating the transmission of acquired paternal traits have drawn great attention because the findings suggest that heritable information can flow from soma to germ line, thus invalidating the long-standing Weismann's barrier theory on heritable information flow. Using small RNA sequencing (sRNA-seq), northern blots, sRNA in situ hybridization, and immunofluorescence, we detected substantial changes in the small RNA profile in murine caput epididymal sperm (sperm in the head of the epididymis), and we further determined that the changes resulted from sperm exchanging small RNAs, mainly tsRNAs and rsRNAs, with cytoplasmic droplets rather than the epididymosomes. Moreover, the murine sperm-borne small RNAs were mainly derived from the nuclear small RNAs in late spermatids. Thus, caution is needed regarding sperm gaining foreign small RNAs as an underlying mechanism of epigenetic inheritance.

MYCT1 attenuates renal fibrosis and tubular injury in diabetic kidney disease.

Tubulointerstitial abnormalities contribute to the progression of diabetic kidney disease (DKD). However, the underlying mechanism of the pathobiology of tubulointerstitial disease is largely unknown. Here, we showed that MYCT1 expression was downregulated in in vitro and in vivo DKD models. Adeno-associated virus (AAV)-Myct1 significantly attenuated renal dysfunction and tubulointerstitial fibrosis in diabetic db/db mice and downregulated Sp1 transcription and TGF-ß1/SMAD3 pathway activation. In human proximal tubular epithelial cells, high glucose-induced high expression of SP1 and TGF-ß1/SMAD3 pathway activation as well as overaccumulation of extracellular matrix (ECM) were abrogated by MYCT1 overexpression. Mechanistically, the binding of VDR to the MYCT1 promoter was predicted and confirmed using dual-luciferase reporter and ChIP analysis. VDR transcriptionally upregulates MYCT1. Our data reveal MYCT1 as a new and potential therapeutic target in treating DKD.

Promoter hypermethylation-induced transcriptional down-regulation of the gene MYCT1 in laryngeal squamous cell carcinoma.

BACKGROUND: MYCT1, previously named MTLC, is a novel candidate tumor suppressor gene. MYCT1 was cloned from laryngeal squamous cell cancer (LSCC) and has been found to be down-regulated in LSCC; however, the regulatory details have not been fully elucidated. METHODS: Here, we sought to investigate the methylation status of the CpG islands of MYCT1 and mRNA levels by bisulfite-specific PCR (BSP) based on sequencing restriction enzyme digestion, reverse transcription and real-time quantitative polymerase chain reaction (RQ-PCR). The function of specific sites in the proximal promoter of MYCT1 in LSCC was measured by transient transfection, luciferase assays, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation assay (ChIP). RESULTS: The results suggested hypermethylation of 12 CpG sites of the promoter in both laryngeal cancer tissues and the laryngeal cancer line Hep-2 cell. The hypermethylation of the site CGCG (-695 to -692), which has been identified as the c-Myc binding site, was identified in laryngeal cancer tissues (59/73) compared to paired mucosa (13/73); in addition, statistical analysis revealed that the methylation status of this site significantly correlated with cancer cell differentiation(p < 0.01). The mRNA level of MYCT1 increased in Hep-2 cells treated with 5-aza-C (p < 0.01). The luciferase activity from mutant transfectants pGL3-MYCT1m (-852/+12, mut-695-C > A, mut-693-C > G) was significantly reduced compared with the wild type pGL3-MYCT1 (-852/+12), while the luciferase activity from wild transfectants pGL3-MYCT1 (-852/+12) rose after 5-aza treatment in Hep-2 cells. Finally, EMSA and ChIP confirmed that the methylation of the CGCG (-695 to -692) site prevented c-Myc from binding of the site and demethylation treatment of the 5' flanking region of MYCT1 by 5-aza induced the increased occupation of the core promoter by c-Myc (p < 0.01). CONCLUSION: In summary, this study concluded that hypermethylation contributed to the transcriptional down-regulation of MYCT1 and could inhibit cancer cell differentiation in LSCC. DNA methylation of the CGCG site (-695 to -692) of MYCT1 altered the promoter activity by interfering with its binding to c-Myc in LSCC. Epigenetic therapy of reactivating MYCT1 by 5-aza should be further evaluated in clinical trails of LSCC.

MYCT1 alters the glycogen shunt by regulating selective translation of RACK1-mediated enzymes.

MYCT1 has been shown to function as a tumor suppressor in various tumors, but its role in metabolism has never been reported. Here, we showed that global inactivation of Myct1 in mice led to progressive accumulation of glycogen in the liver, which was accompanied by aberrant changes in intermediates of the glycogen metabolic pathway. Mechanistically, MYCT1 appeared to promote translation efficiency of PGM1, UGP2 and GSK3A in hepatic cells in a RACK1-dependent manner. Consequently, upregulation of the three enzymes enhanced the glycogen shunt. Our data reveal a critical role of MYCT1 as a switch for the glycogen shunt in tumor cells.

Overexpression of DOCK6 in oral squamous cell cancer promotes cellular migration and invasion and is associated with poor prognosis.

OBJECTIVE: We aimed to identify the role of DOCK6 in oral squamous cell cancer (OSCC) in this study. DESIGN: DOCK6 expression in OSCC was analyzed using TCGA and GEO datasets and was verified by quantitative real-time PCR, Western blotting, and immunohistochemistry. Statistical analyses were performed to evaluate the relationships between DOCK6 expression and the clinicopathological characteristics of OSCC patients. Wound healing and Transwell assays were performed to assess OSCC cell migration and invasion, respectively. STRING and GO analyses and gene set enrichment analysis were used to identify DOCK6-interacting proteins, their functions and their potential pathways. RESULTS: DOCK6 was significantly upregulated at both the mRNA and protein levels in OSCC tissues (all P < 0.05). DOCK6 levels were positively correlated with age (P < 0.05), lymph node metastasis status (P < 0.001), clinical stage (P < 0.001), differentiation (P < 0.05), and poor clinical outcome (P < 0.05) in OSCC patients. Furthermore, univariate and multivariate analyses revealed that high DOCK6 expression (P < 0.01) and clinical stage III-IV (P < 0.05) might serve as independent prognostic factors for OSCC patients. Functionally, DOCK6 silencing significantly suppressed OSCC cell migration and invasion (all P < 0.05). Ten proteins that interact with DOCK6, more than ten functions related to cancer, and more than six pathways related to DOCK6 in OSCC were identified via bioinformatic methods. CONCLUSION: DOCK6 is upregulated in OSCC, is associated with a poor prognosis in OSCC patients and increases OSCC cells migration and invasion. These findings suggest that DOCK6 may be a potential therapeutic target with prognostic implication in patients with OSCC.

The TBX1/miR-193a-3p/TGF-ß2 Axis Mediates CHD by Promoting Ferroptosis.

Congenital heart disease (CHD) is the most common noninfectious cause of death during the neonatal stage. T-box transcription factor 1 (TBX1) is the main genetic determinant of 22q11.2 deletion syndrome (22q11.2DS), which is a common cause of CHD. Moreover, ferroptosis is a newly discovered kind of programmed cell death. In this study, the interaction among TBX1, miR-193a-3p, and TGF-ß2 was tested using quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blotting, and dual-luciferase reporter assays. TBX1 silencing was found to promote TGF-ß2 messenger ribonucleic acid (mRNA) and protein expression by downregulating the miR-193a-3p levels in H9c2 cells. In addition, the TBX1/miR-193a-3p/TGF-ß2 axis was found to promote ferroptosis based on assessments of lipid reactive oxygen species (ROS) levels, Fe2+ concentrations, mitochondrial ROS levels, and malondialdehyde (MDA) contents; Cell Counting Kit-8 (CCK-8) assays and transmission electron microscopy; and Western blotting analysis of glutathione peroxidase 4 (GPX4), nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), NADPH oxidase 4 (NOX4), and acyl-CoA synthase long-chain family member 4 (ACSL4) protein expression. The protein expression of NRF2, GPX4, HO-1, NOX4, and ACSL4 and the level of MDA in human CHD specimens were also detected. In addition, TBX1 and miR-193a-3p expression was significantly downregulated and TGF-ß2 levels were high in human embryonic CHD tissues, as indicated by the H9c2 cell experiments. In summary, the TBX1/miR-193a-3p/TGF-ß2 axis mediates CHD by inducing ferroptosis in cardiomyocytes. TGF-ß2 may be a target gene for CHD diagnosis and treatment in children.

14-3-3epsilon contributes to tumour suppression in laryngeal carcinoma by affecting apoptosis and invasion.

BACKGROUND: 14-3-3epsilon regulates a wide range of biological processes, including cell cycle control, proliferation, and apoptosis, and plays a significant role in neurogenesis and the formation of malignant tumours. However, the exact function and regulatory mechanism of 14-3-3epsilon in carcinogenesis have not been elucidated. METHODS: The expression of 14-3-3epsilon was assessed by RT-PCR and western blotting. The invasiveness and viability of Hep-2 cells were determined by the transwell migration assay and MTT assay, respectively. Cell cycle and apoptosis of Hep-2 cells were detected by flow cytometry. RESULTS: The mRNA and protein expression of 14-3-3epsilon in larynx squamous cell carcinoma (LSCC) tissues were significantly lower than those in clear surgical margin tissues. Statistical analysis showed that the 14-3-3epsilon protein level in metastatic lymph nodes was lower than that in paired tumour tissues. In addition, the protein level of 14-3-3epsilon in stage III or IV tumours was significantly lower than that in stage I or II tumours. Compared with control Hep-2 cells, the percentages of viable cells in the 14-3-3epsilon-GFP and negative control GFP groups were 36.68 +/- 14.09% and 71.68 +/- 12.10%, respectively. The proportions of S phase were 22.47 +/- 3.36%, 28.17 +/- 3.97% and 46.15 +/- 6.82%, and the apoptotic sub-G1 populations were 1.23 +/- 1.02%, 2.92 +/- 1.59% and 13.72 +/- 3.89% in the control, negative control GFP and 14-3-3epsilon-GFP groups, respectively. The percentages of the apoptotic cells were 0.84 +/- 0.25%, 1.08 +/- 0.24% and 2.93 +/- 0.13% in the control, negative control GFP and 14-3-3epsilon-GFP groups, respectively. The numbers of cells that penetrated the filter membrane in the control, negative control GFP and 14-3-3epsilon-GFP groups were 20.65 +/- 1.94, 17.63 +/- 1.04 and 9.1 +/- 0.24, respectively, indicating significant differences among the different groups. CONCLUSIONS: Decreased expression of 14-3-3epsilon in LSCC tissues contributes to the initiation and progression of LSCC. 14-3-3epsilon can promote apoptosis and inhibit the invasiveness of LSCC.

SH3GL2 gene participates in MEK-ERK signal pathway partly by regulating EGFR in the laryngeal carcinoma cell line Hep2.

BACKGROUND: The human Src homology 3 (SH3) domain GRB2-like 2 (SH3GL2) gene, a novel tumor suppressor gene in laryngeal squamous cell carcinoma (LSCC), induces apoptosis of tumor cells by regulating intra-cellular signal transduction networks. The objective of this study was to investigate the molecular mechanism of SH3GL2 in laryngeal carcinogenesis. MATERIAL/METHODS: RNA interference inhibited the expression of level of SH3GL, and RT-PCR and Western blotting were applied to evaluate the expression level of SH3GL2 after RNA interference. After RNA interference, flow cytometry and 3-(4,5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay were used to detect the biological effects, and Western blotting was used to determine the expression of EGFR and phosphorylated ERK1/2. The Hep2 cells transfected with siRNA-SH3GL2 were treated by U0126 (selective MEK1/2 Inhibitor), and the phosphorylated ERK1/2 proteins were detected by Western blotting; cell proliferation and apoptosis were detected subsequently. RESULTS: Our results show that the expression level of epidermal growth factor receptor (EGFR) and phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) were up-regulated after down-regulation of SH3GL2. Additionally, SH3GL2 promoted apoptosis while decreasing cell proliferation. However, if ERK1/2 was inhibited by U0126, the apoptosis rate increased and proliferation decreased inversely. CONCLUSIONS: SH3GL2 participates in the regulation of apoptosis through the MEK-ERK signal pathway by adjusting EGFR in the laryngeal carcinoma cell line Hep2.

Low expression of Sp100 in laryngeal cancer: correlation with cell differentiation.

BACKGROUND: Sp100 is a permanent ProMyelocytic Leukaemian nuclear bodies (PML NB)-associated protein, and has been reported to participate in the regulation of transcriptional activity, apoptosis and other cellular biological processes. The aim of the present study was to explore the expression of Sp100 and its potential clinical implications in laryngeal cancer. MATERIAL/METHODS: The mRNA and protein levels of Sp100 in 96 laryngeal cancer samples and paired normal epithelium were examined by RT-PCR, Western blot and immuno-histochemical staining. The correlation of Sp100 expression with clinicopathological features of these patients was assessed by Chi-squared test. RESULTS: The coherent low Sp100 expression of both transcriptional and translational levels were confirmed in the malignant tissues compared to the normal mucosa, and the expression was down-regulated among the well-, moderately- and poorly-differentiated cancer cells accordingly. Moreover, immuno-histochemical staining demonstrated that Sp100 showed a predominantly nuclear pattern in well-differentiated cancer cells, and diffuse cellular distribution in cytoplasm in poorly-differentiated cancer cells. Besides histological type of cancer cells, other clinicopathological characteristics, including age, sex, T classification, lymph node metastasis, distant metastasis and clinical stage, showed no significant correlation with Sp100 low expression. CONCLUSIONS: Our finding provides an important clue to further understanding the role of Sp100 in the initiation and progression of tumorgenesis.

MYCT1 Inhibits the Adhesion and Migration of Laryngeal Cancer Cells Potentially Through Repressing Collagen VI.

MYCT1, a target of c-Myc, inhibits laryngeal cancer cell migration, but the underlying mechanism remains unclear. In the study, we detected differentially expressed genes (DEGs) from laryngeal cancer cells transfected by MYCT1 using RNA-seq (GSE123275). DEGs from head and neck squamous cell carcinoma (HNSCC) were first screened by comparison of transcription data from the Gene Expression Omnibus (GSE6631) and the Cancer Genome Atlas (TCGA) datasets using weighted gene co-expression network analysis (WGCNA). GO and KEGG pathway analysis explained the functions of the DEGs. The DEGs overlapped between GSE6631and TCGA datasets were then compared with ours to find the key DEGs downstream of MYCT1 related to the adhesion and migration of laryngeal cancer cells. qRT-PCR and Western blot were applied to validate gene expression at mRNA and protein levels, respectively. Finally, the cell adhesion, migration, and wound healing assays were to check cell adhesion and migration abilities, respectively. As results, 39 overlapping genes were enriched in the GSE6631 and TCGA datasets, and most of them revealed adhesion function. Thirteen of 39 genes including COL6 members COL6A1, COL6A2, and COL6A3 were overlapped in GSE6631, TCGA, and GSE123275 datasets. Similar to our RNA-seq results, we confirmed that COL6 is a target of MYCT1 in laryngeal cancer cells. We also found that MYCT1 inhibited the adhesion and migration of laryngeal cancer cells via COL6. These indicate that COL6 is a potential target of MYCT1 and participates the adhesion and migration of laryngeal cancer cells, which provides an important clue for further study on how MYCT1 regulating COL6 in laryngeal cancer progression.

MYCT1 inhibits the EMT and migration of laryngeal cancer cells via the SP1/miR-629-3p/ESRP2 pathway.

MYCT1 has an inhibitory effect on the migration of laryngeal cancer cells, although the underlying molecular mechanism remains unknown. In this study, we aimed to explore the mechanism of MYCT1 in the epithelial-mesenchymal transition (EMT) and migration of laryngeal cancer cells. We found that MYCT1 significantly decreased the expression of miR-629-3p but increased the expression of ESRP2 in laryngeal cancer cells. The expression of miR-629-3p and ESRP2 in laryngeal cancer tissues showed significantly positive and negative correlations with patient metastasis, respectively. miR-629-3p was confirmed to repress the expression of ESRP2 by targeting its 3'UTR. SP1 was verified to be a direct transcription factor for miR-629-3p and a downstream target of MYCT1. Moreover, MYCT1 inhibited the EMT and migration of laryngeal cancer cells through the SP1/miR-629-3p/ESRP2 pathway. Taken together, our results establish a novel MYCT1 signaling pathway in the EMT and migration of laryngeal cancer cells, thus providing important insights for further studying the pathway in the diagnosis and treatment of laryngeal cancer.

TBX3 deficiency accelerates apoptosis in cardiomyoblasts through regulation of P21 expression.

Congenital heart disease (CHD) is the most common birth defect in newborns. There is increasing evidence that apoptosis and remodeling of the cardiomyoblasts are the major pathology of CHD. Previous research found that T-box transcription factor 3 (TBX3) was compulsory for the regulation of proliferation, cell cycle arrest and apoptosis in various cells. Hence, TBX3 might be involved in the treatment of CHD. The primary aim of this study was to study the effects of TBX3 on apoptosis in aged cardiomyoblasts and investigate the latent mechanism. In the present study, we found TBX3 knockdown induced proliferation inhibition, cell cycle arrest and apoptosis accompanied by mitochondrial dysfunction in cardiomyoblasts at passage 10 to 15. Apoptosis-inducing effects of TBX3 silence could be neutralized by silencing P21 using specific siRNA. In addition, the mRNA and protein expression levels of TBX3 in the heart tissues of sporadic type CHD donors were obviously down-regulated. In conclusion, we demonstrated that TBX3 deficiency accelerated apoptosis via directly regulating P21 expression in senescent cardiomyoblasts.