HDAC5, negatively regulated by miR-148a-3p, promotes colon cancer cell migration.

Histone deacetylases (HDACs) are involved in many processes including tumor cell growth and proliferation and regulation of gene expression. To clarify the role of class IIa HDACs in the metastasis of colon adenocarcinoma, we used the class IIa HDAC inhibitor TMP269 and found that it effectively inhibited the migration ability of colon adenocarcinoma cells. Next, we silenced the member of class IIa HDACs and confirmed that the migratory ability of colon adenocarcinoma cells was significantly inhibited by silencing HDAC5 or HDAC7. HDAC5 plays a variety of roles in human cancers. Here, we examined the role of HDAC5 in colon adenocarcinoma. The results indicated that HDAC5 was highly expressed in tumor tissues and negatively correlated with the expression of miR-148a-3p. Moreover, the expression of HDAC5 was correlated with tumor progression. HDAC5 markedly increased the invasion and migration of cancer cells in vitro, an effect that could be inhibited by overexpression of miR-148a-3p. Following an intraperitoneal injection of colon adenocarcinoma cells in athymic nude mice, HDAC5 promoted tumor implant. Together, these findings showed that HDAC5 overexpression in colon adenocarcinoma is consistent with tumor progression and tumor cell migration and the impact of HDAC5 overexpression is reduced by miR-148a-3p.

Tweety homolog 3 promotes colorectal cancer progression through mutual regulation of histone deacetylase 7.

Colorectal cancer (CRC) is one of the leading cancers worldwide, with metastasis being a major cause of high mortality rates among patients. In this study, dysregulated gene Tweety homolog 3 (TTYH3) was identified by Gene Expression Omnibus database. Public databases were used to predict potential competing endogenous RNAs (ceRNAs) for TTYH3. Quantitative real-time polymerase chain reaction, western blot, and immunohistochemistry were utilized to analyze TTYH3 and histone deacetylase 7 (HDAC7) levels. Luciferase assays confirmed miR-1271-5p directly targeting the 3' untranslated regions of TTYH3 and HDAC7. In vitro experiments such as transwell and human umbilical vein endothelial cell tube formation, as well as in vivo mouse models, were conducted to assess the biological functions of TTYH3 and HDAC7. We discovered that upregulation of TTYH3 in CRC promotes cell migration by affecting the Epithelial-mesenchymal transition pathway, which was independent of its ion channel activity. Mechanistically, TTYH3 and HDAC7 functioned as ceRNAs, reciprocally regulating each other's expression. TTYH3 competes for binding miR-1271-5p, increasing HDAC7 expression, facilitating CRC metastasis and angiogenesis. This study reveals the critical role of TTYH3 in promoting CRC metastasis through ceRNA crosstalk, offering new insights into potential therapeutic targets for clinical intervention.

Downregulation of MEIS1 mediated by ELFN1-AS1/EZH2/DNMT3a axis promotes tumorigenesis and oxaliplatin resistance in colorectal cancer.

Oxaliplatin is widely used in the frontline treatment of colorectal cancer (CRC), but an estimated 50% of patients will eventually stop responding to treatment due to acquired resistance. This study revealed that diminished MEIS1 expression was detected in CRC and harmed the survival of CRC patients. MEIS1 impaired CRC cell viabilities and tumor growth in mice and enhanced CRC cell sensitivity to oxaliplatin by preventing DNA damage repair. Mechanistically, oxaliplatin resistance following MEIS1 suppression was critically dependent on enhanced FEN1 expression. Subsequently, we confirmed that EZH2-DNMT3a was assisted by lncRNA ELFN1-AS1 in locating the promoter of MEIS1 to suppress MEIS1 transcription epigenetically. Based on the above, therapeutics targeting the role of MEIS1 in oxaliplatin resistance were developed and our results suggested that the combination of oxaliplatin with either ELFN1-AS1 ASO or EZH2 inhibitor GSK126 could largely suppress tumor growth and reverse oxaliplatin resistance. This study highlights the potential of therapeutics targeting ELFN1-AS1 and EZH2 in cell survival and oxaliplatin resistance, based on their controlling of MEIS1 expression, which deserve further verification as a prospective therapeutic strategy.

MEF2A transcriptionally upregulates the expression of ZEB2 and CTNNB1 in colorectal cancer to promote tumor progression.

Colorectal cancer (CRC) is one of the leading cancers worldwide, accounting for high morbidity and mortality. The mechanisms governing tumor growth and metastasis in CRC require detailed investigation. The results of the present study indicated that the transcription factor (TF) myocyte enhancer factor 2A (MEF2A) plays a dual role in promoting proliferation and metastasis of CRC by inducing the epithelial-mesenchymal transition (EMT) and activation of WNT/ß-catenin signaling. Aberrant expression of MEF2A in CRC clinical specimens was significantly associated with poor prognosis and metastasis. Functionally, MEF2A directly binds to the promoter region to initiate the transcription of ZEB2 and CTNNB1. Simultaneous activation of the expression of EMT-related TFs and Wnt/ß-catenin signaling by MEF2A overexpression induced the EMT and increased the frequency of tumor formation and metastasis. The present study identified a new critical oncogene involved in the growth and metastasis of CRC, providing a potential novel therapeutic target for CRC intervention.

[Restoration of pathological changes of emphysema by angiogenesis factors: experiment of rats].

OBJECTIVE: To investigate whether intratracheal administration of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) restore the pulmonary function and pathology in emphysema, and research the mechanism of they restored pulmonary emphysema, and the pathogenesis of pulmonary emphysema. METHODS: Twenty-four Wistar rats were randomized into the 4 equal groups: bFGF group [receiving a single intratracheal instillation of porcine pancreatic elastase (PPE) 250 U/kg, and 4 weeks later receiving intratracheal instillation of bFGF 400 U once a week for 3 weeks), VEGF group (receiving a single intratracheal instillation of PPE 250 U/kg, and 4 weeks later receiving intratracheal instillation of VEGF 2 microg once a week for 3 weeks), control group [receiving a single intratracheal instillation of PPE 250 U/kg, and 4 weeks later receiving intratracheal instillation of normal saline (NS) once a week for 3 weeks], and normal group (receiving intratracheal instillation of NS in above-mentioned pattern). Four weeks after treatment, arterial blood sample was collected from the abdominal aorta to undergo blood gas analysis for assessment pulmonary function, and then the rata were killed with their lungs taken out to undergo pathological examination. Immunohistochemistry was performed to detect the CD34, markers of pulmonary capillary endothelial cells. RESULTS: There were no significant differences in the artery blood gas analysis among the four groups (all P > 0.05). The levels of mean alveoli number (MAN) of the bFGF and VEGF groups were (43 +/- 8)/HP and (44 +/- 9)/HP] respectively, both significantly higher than that of the control group [(30 +/- 6)/HP, both P < 0.01]. The levels of mean linear intercept (MLI) of the bFGF and VEGF groups were (196 +/- 38) microm and (194 +/- 38) microm respectively, both significantly lower than that of the control group [(288 +/- 68) microm, both P < 0.01). the mean alveoli area (MAA) level of the bFGF and VEGF groups were (9856 +/- 1864) microm(2) and (9804 +/- 1929) microm(2) respectively, both significantly lower than that of the control group [(14,525 +/- 3408) microm(2), both P < 0.01]. The percentages of CD34(+) cells of the bFGF and VEGF groups were (3.7 +/- 1.3)% and (2.6 +/- 1.2)% respectively, both significantly higher than that of the control group [(0.8 +/- 0.7)%, both P < 0.05). CONCLUSION: bFGF and VEGF can restore the pathological changes of experimental emphysema. The damage of pulmonary capillary may play an important role in the pathogenesis of pulmonary emphysema.