TEAD2 initiates ground-state pluripotency by mediating chromatin looping

The transition of mouse embryonic stem cells (ESCs) between serum/LIF and 2i(MEK and GSK3 kinase inhibitor)/LIF culture conditions serves as a valuable model for exploring the mechanisms underlying ground and confused pluripotent states. Regulatory networks comprising core and ancillary pluripotency factors drive the gene expression programs defining stable naïve pluripotency. In our study, we systematically screened factors essential for ESC pluripotency, identifying TEAD2 as an ancillary factor maintaining ground-state pluripotency in 2i/LIF ESCs and facilitating the transition from serum/LIF to 2i/LIF ESCs. TEAD2 exhibits increased binding to chromatin in 2i/LIF ESCs, targeting active chromatin regions to regulate the expression of 2i-specific genes. In addition, TEAD2 facilitates the expression of 2i-specific genes by mediating enhancer-promoter interactions during the serum/LIF to 2i/LIF transition. Notably, deletion of Tead2 results in reduction of a specific set of enhancer-promoter interactions without significantly affecting binding of chromatin architecture proteins, CCCTC-binding factor (CTCF), and Yin Yang 1 (YY1). In summary, our findings highlight a novel prominent role of TEAD2 in orchestrating higher-order chromatin structures of 2i-specific genes to sustain ground-state pluripotency.

Mass Spectrometry-Based Proteomics Identifies Serpin B9 as a Key Protein in Promoting Bone Metastases in Lung Cancer

Bone metastasis (BM) is one of the most common complications of advanced cancer. Immunotherapy for bone metastasis of lung cancer (LCBM) is not so promising and the immune mechanisms are still unknown. Here, we utilized a model of BM by injecting cancer cells through caudal artery (CA) to screen out a highly bone metastatic derivative (LLC1-BM3) from a murine lung cancer cell line LLC1. Mass spectrometry-based proteomics was performed in LLC1-parental and LLC1-BM3 cells. Combining with prognostic survival information from patients with lung cancer, we identified serpin B9 (SB9) as a key factor in BM. Molecular characterization showed that SB9 overexpression was associated with poor prognosis and high bone metastatic burden in lung cancer. Moreover, SB9 could increase the ability of lung cancer cells to metastasize to the bone. The mechanistic studies revealed that tumor-derived SB9 promoted BM through an immune cell-dependent way by inactivating granzyme B, manifesting with the decreased infiltration of cytotoxic T cells and increased expression level of exhausted markers. A specific SB9-targeting inhibitor [1,3-benzoxazole-6-carboxylic acid (BTCA)] significantly suppressed LCBM in the CA mouse model. This study reveals that SB9 may serve as a therapeutic target and potential prognostic marker for patients with LCBM.

IMPLICATIONS

SB9 as a therapeutic target for LCBM.

CircMMP2(6,7) Cooperates with β-Catenin and PRMT5 to Disrupt Bone Homeostasis and Promote Breast Cancer Bone Metastasis

The bone is the most common site of distant metastasis of breast cancer, which leads to serious skeletal complications and mortality. Understanding the mechanisms underlying breast cancer bone metastasis would provide potential strategies for the prevention and treatment of breast cancer bone metastasis. In this study, we identified a circular RNA that we named circMMP2(6,7) that was significantly upregulated in bone metastatic breast cancer tissues and correlated with breast cancer-bone metastasis. Upregulation of circMMP2(6,7) dramatically enhanced the metastatic capability of breast cancer cells to the bone via inducing bone metastatic niche formation by disrupting bone homeostasis. Mechanistically, circMMP2(6,7) specifically bound to the promoters of bone-remodeling factors calcium-binding protein S100A4 and carbohydrate-binding protein LGALS3 and formed a complex with β-catenin and arginine methyltransferase PRMT5, eliciting histone H3R2me1/H3R2me2s-induced transcriptional activation. Treatment with GSK591, a selective PRMT5 inhibitor, effectively inhibited circMMP2(6,7)/β-catenin/PRMT5 complex-induced breast cancer bone metastasis. These findings reveal a role for circMMP2(6,7) in bone homeostasis disruption and shed light on the mechanisms driving breast cancer bone metastasis.

SIGNIFICANCE

Upregulation of bone-remodeling factors S100A4 and LGALS3 mediated by a circMMP2(6,7)/β-catenin/PRMT5 complex generates a niche that supports breast cancer bone metastasis, identifying PRMT5 as a promising target for treating metastasis.

Mobile Phone Use and Risks of Overall and 25 Site-Specific Cancers: A Prospective Study from the UK Biobank Study

BACKGROUND

The association between mobile phone use and incident cancers remains uncertain. We aimed to investigate the relationships of mobile phone use with incident overall and 25 site-specific cancers in men and women.

METHODS

A total of 431,861 participants ages 38 to 73 years without prior cancers were included from the UK Biobank. Of these, 46.7% were male. Participants who used a mobile phone at least once per week to make or receive calls were defined as mobile phone users. The study outcomes were incident overall and 25 site-specific cancers.

RESULTS

During a median follow-up of 10.7 years, 35,401 (17.5%) men and 30,865 (13.4%) women developed overall cancer. Mobile phone use was significantly associated with higher risks of incident overall cancer [HR, 1.09; 95% confidence interval (CI): 1.06-1.12], nonmelanoma skin cancer (NMSC; HR, 1.08; 95% CI: 1.03-1.14), urinary tract cancer (HR, 1.18; 95% CI:1.05-1.32), and prostate cancer (HR, 1.19; 95% CI: 1.13-1.25) in men, and incident overall cancer (HR, 1.03; 95% CI: 1.00-1.06), NMSC (HR, 1.07; 95% CI: 1.01-1.13), and vulva cancer (HR, 1.74; 95% CI: 1.00-3.02) in women, but not with other cancers. Among mobile phone users, there was a dose-response relationship of length of mobile phone use with incident NMSC in men and women, and prostate cancer in men (all Ptrend < 0.05).

CONCLUSIONS

There was a dose-response relationship of length of mobile phone use with incident NMSC in men and women, and prostate cancer in men.

IMPACT

Our findings underscore the importance of limiting mobile phone use or keeping a distance from mobile phone for primary prevention of NMSC and prostate cancer.