E2F2 modulates cell adhesion through the transcriptional regulation of PECAM1 in multiple myeloma

Multiple myeloma (MM) is the second most common haematological malignancy. Despite the development of new drugs and treatments in recent years, the therapeutic outcomes of patients are not satisfactory. It is necessary to further investigate the molecular mechanism underlying MM progression. Herein, we found that high E2F2 expression was correlated with poor overall survival and advanced clinical stages in MM patients. Gain- and loss-of-function studies showed that E2F2 inhibited cell adhesion and consequently activated cell epithelial-to-mesenchymal transition (EMT) and migration. Further experiments revealed that E2F2 interacted with the PECAM1 promoter to suppress its transcriptional activity. The E2F2-knockdown-mediated promotion of cell adhesion was significantly reversed by the repression of PECAM1 expression. Finally, we observed that silencing E2F2 significantly inhibited viability and tumour progression in MM cell models and xenograft mouse models respectively. This study demonstrates that E2F2 plays a vital role as a tumour accelerator by inhibiting PECAM1-dependent cell adhesion and accelerating MM cell proliferation. Therefore, E2F2 may serve as a potential independent prognostic marker and therapeutic target for MM.

Targeting hexokinase 2 increases the sensitivity of oxaliplatin by Twist1 in colorectal cancer

Colorectal cancer (CRC) is the third most malignant tumour worldwide, with high mortality and recurrence. Chemoresistance is one of the main factors leading to metastasis and poor prognosis in advanced CRC patients. By analysing the Gene Expression Omnibus data set, we found higher hexokinase 2 (HK2) expression levels in patients with metastatic CRC than in those with primary CRC. Moreover, we observed higher enrichment in oxaliplatin resistance‐related gene sets in metastatic CRC than in primary CRC. However, the underlying relationship has not yet been elucidated. In our study, HK2 expression was significantly elevated in CRC patients. Gene set enrichment analysis (GSEA) revealed multi‐drug resistance and epithelial‐mesenchymal transition (EMT) pathways related to high HK2 expression. Our results showed that knockdown of HK2 significantly inhibited vimentin and Twist1 expression and promoted TJP1 and E‐cadherin expression in CRC cells. Additionally, transcriptional and enzymatic inhibition of HK2 by 3‐bromopyruvate (3‐bp) impaired oxaliplatin resistance in vitro and in vivo. Mechanistically, HK2 interacts with and stabilized Twist1 by preventing its ubiquitin‐mediated degradation, which is related to oxaliplatin resistance, in CRC cells. Overexpression of Twist1 reduced the apoptosis rate by HK2 knockdown in CRC cells. Collectively, we discovered that HK2 is a crucial regulator that mediates oxaliplatin resistance through Twist1. These findings identify HK2 and Twist1 as promising drug targets for CRC chemoresistance.

Methylation of the Promoter Region of the Tight Junction Protein-1 by DNMT1 Induces EMT-like Features in Multiple Myeloma

The molecular alterations that initiate the development of multiple myeloma (MM) are not fully understood. Our results revealed that TJP1 was downregulated in MM and positively related to the overall survival of MM patients in The Cancer Genome Atlas (TCGA) database and patient samples. In parallel, cell adhesion capacity representing MM metastasis was decreased in MM patients compared with healthy samples, together with the significantly activated epithelial-to-mesenchymal transition (EMT) transcriptional-like patterns of MM cells. Further analyses demonstrated that TJP1 negatively regulated EMT and consequently positively regulated cell adhesion in MM from TCGA database and MM1s cells. Furthermore, the methylation level of each CpG site on the TJP1 promoter was negatively correlated with TJP1 expression levels. Quantitative real-time PCR and western blot assays demonstrated that methylase DNMT1 regulated the methylation of TJP1. Finally, treatment with a combination of the MM clinical medicine bortezomib, methylation inhibitor, or TJP1 overexpression significantly suppressed the viability and progression of tumor cells of MM orthotopic models. In summary, our results indicate that DNMT1 promotes the methylation of TJP1 promoter, thereby decreasing its expression and regulating the development of EMT-inhibited MM cell adhesion. Therefore, methylation of TJP1 is a potential therapeutic agent to prevent the progression of MM disease.

[Value of anti-Müllerian hormone in predicting pregnant outcomes of polycystic ovary syndrome patients undergone assisted reproductive technology]

Objective: Explore the value of anti-Müllerian hormone (AMH) in predicting pregnant outcomes of polycystic ovary syndrome (PCOS) patients undergone assisted reproductive technology. Methods: The study totally recruited 1 697 patients who underwent the first in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycle in Sun Yat-sen Memorial Hospital from the January 2014 to December 2015. The patients were divided into two groups based on the age<35 (n=758) and ≥35 years old (n=939) , compare the basic data and pregnant outcomes of controlled ovarian hyerstimulation. Spearman correlation method was conducted to analyze the relations between AMH and clinical outcomes. The logistic regression method and partial correlation analysis were used to judge the main factors which determine pregnancy outcomes by controlled the confounding factors. The receiver operating characteristic curve (ROC) was used to evaluate the predictive sensitivity and specificity of AMH. Results: In the group of PCOS patient younger than 35 years, AMH were correlated with the number of antral follicles (r=0.388) and retrieved oocytes (r=0.235) . When the effect of total dosage and starting dosage of gonadotropin were controlled, AMH was still significantly associated with the number of retrieved oocytes (P<0.05) . AMH had no predictive value for the clinical pregnancy of PCOS patient younger than 35 years (area under ROC curve=0.481, P=0.768) . In the group of PCOS patient≥35 years old, AMH were correlated with the number of antral follicles (r=0.450) , retrieved oocytes (r=0.399) , available embryo (r=0.336) and high quality embryo (r=0.235) . When the effect of total dosage and starting dosage of gonadotropin were controlled, the correlations were still significant between those indexes (all P<0.05) . AMH had no predictive value for the clinical pregnancy of PCOS patient ≥35 years old (area under ROC curve=0.535, P=0.560) . However, the clinical pregnancy rate of the group of PCOS patient ≥35 years old was slightly higher than the control group (P=0.062) . Conclusions: AMH has no predictive value for the pregnancy outcome of PCOS patient. The pregnancy rate of PCOS patient ≥35 years old is slightly higher than the younger group, because the PCOS patient may have better ovarian reserve.