ZBTB7A functioned as an oncogene in colorectal cancer

ZBTB7A as a therapeutic target for cancer

ZBTB7A, alternatively referred to Pokemon, FBI-1, LRF, and OCZF, is classified as a member of POK/ZBTB protein family of transcriptional repressors. ZBTB7A binds to targeted DNA via C-terminal zinc fingers and recruits co-compression complexes through N-terminal BTB ⁄ POZ domain to impede transcription. ZBTB7A regulates a range of fundamental biological processes such as cell proliferation, differentiation and apoptosis, B- and T-lymphocyte fate determination and thymic insulin expression and self-tolerance. Accumulating evidence has demonstrated an important role of ZBTB7A in the initiation and advancement of tumors, thus making ZBTB7A emerge as an appealing target. This review examines the functions and regulatory mechanisms of ZBTB7A in a range of common solid tumors, including hepatocellular carcinoma, breast cancer, prostate cancer and lung cancer, as well as hematological malignancies. Notably, the review concludes with a summary of the recent applications of targeting ZBTB7A in clinical treatments through gene silencing, immunotherapy and chemotherapeutic approaches to halt or slow tumor progression. We focus on the functional role and regulatory mechanisms of ZBTB7A in cancer with the goal of providing new insights for the development of more effective cancer therapeutic strategies.

ZBTB7A interferes with the RPL5-P53 feedback loop and reduces endoplasmic reticulum stress-induced apoptosis of pancreatic cancer cells

Endoplasmic reticulum (ER) stress is a primary mechanism leading to cell apoptosis, making it of great research interests in cancer management. This study delves into the function of ribosomal protein L5 (RPL5) in ER stress within pancreatic cancer (PCa) cells and investigates its regulatory mechanisms. Bioinformatics predictions pinpointed RPL5 as an ER stress-related gene exhibiting diminished expression in PCa. Indeed, RPL5 was found to be poorly expressed in PCa tissues and cells, with this reduced expression correlating with an unfavorable prognosis. Moreover, RPL5 overexpression led to heightened levels of p-PERK, p-eIF2α, and CHOP, bolstering the proapoptotic effect of Tunicamycin, an ER stress activator, on PCa cells. Additionally, the RPL5 overexpression curbed cell proliferation, migration, and invasion. Tunicamycin enhanced the binding between RPL5 and murine double minute 2 (MDM2), thus suppressing MDM2-mediated ubiquitination and degradation of P53. Consequently, P53 augmentation intensified ER stress, which further enhanced the binding between RPL5 and MDM2 through PERK-dependent eIF2α phosphorylation, thereby establishing a positive feedback loop. Zinc finger and BTB domain containing 7A (ZBTB7A), conspicuously overexpressed in PCa samples, repressed RPL5 transcription, thereby reducing P53 expression. Silencing of ZBTB7A heightened ER stress and subdued the malignant attributes of PCa cells, effects counteracted upon RPL5 silencing. Analogous outcomes were recapitulated in vivo employing a xenograft tumor mouse model, where ZBTB7A silencing dampened the tumorigenic potential of PCa cells, an effect reversed by additional RPL5 silencing. In conclusion, this study suggests that ZBTB7A represses RPL5 transcription, thus impeding the RPL5-P53 feedback loop and mitigating ER-induced apoptosis in PCa cells.

Gene regulatory network inference based on causal discovery integrating with graph neural network

Gene regulatory network (GRN) inference from gene expression data is a significant approach to understanding aspects of the biological system. Compared with generalized correlation‐based methods, causality‐inspired ones seem more rational to infer regulatory relationships. We propose GRINCD, a novel GRN inference framework empowered by graph representation learning and causal asymmetric learning, considering both linear and non‐linear regulatory relationships. First, high‐quality representation of each gene is generated using graph neural network. Then, we apply the additive noise model to predict the causal regulation of each regulator‐target pair. Additionally, we design two channels and finally assemble them for robust prediction. Through comprehensive comparisons of our framework with state‐of‐the‐art methods based on different principles on numerous datasets of diverse types and scales, the experimental results show that our framework achieves superior or comparable performance under various evaluation metrics. Our work provides a new clue for constructing GRNs, and our proposed framework GRINCD also shows potential in identifying key factors affecting cancer development.

ZBTB7A, a miR-144-3p targeted gene, accelerates bladder cancer progression via downregulating HIC1 expression

Background

Zinc finger and BTB domain-containing 7A (ZBTB7A) is a member of the POK family of transcription factors that plays an oncogenic or tumor-suppressive role in different cancers depending on the type and genetic context of cancer. However, the function and molecular mechanism of ZBTB7A in bladder cancer (BC) remain elusive.

Methods

The role of ZBTB7A in bladder cancer was detected by colony formation, transwell, and tumor formation assays. The expression levels of ZBTB7A, HIC1, and miR-144-3p were analyzed by qRT-PCR and Western blot. Bioinformatics analysis and a dual-luciferase reporter assay were used to assess the effect of ZBTB7A on the promoter activity of HIC1.

Results

The present study revealed that knockdown of ZBTB7A suppressed BC cell growth and migration, as indicated by an approximately 50% reduction in the number of colonies and an approximately 70% reduction in the number of migrated cells. Loss of ZBTB7A inhibited tumor growth in vivo, resulting in a 75% decrease in tumor volume and an 80% decrease in tumor weight. Further mechanistic studies revealed that ZBTB7A bound to the hypermethylated in cancer 1 (HIC1) promoter and downregulated HIC1 expression, accelerating the malignant behavior of BC. Increased expression of ZBTB7A in BC tissues was negatively corrected with the expression of HIC1. Moreover, ZBTB7A was a target of miR-144-3p, which decreased ZBTB7A expression in BC.

Conclusion

Our data demonstrate that ZBTB7A, a targeted gene of miR-144-3p, promoted tumorigenesis of BC through downregulating HIC1 expression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02596-w.

Long non-coding RNA p53 upregulated regulator of p53 levels (PURPL) promotes the development of gastric cancer

Gastric cancer (GC), one of the most prevalent malignancies across the world, has an increasing incidence rate. Long non-coding RNA (lncRNA) PURPL (also referred to as LINC01021) has been demonstrated to influence malignant GC behaviors and partake in other cancers. Notwithstanding, reports pertaining to the underlying mechanism of PURPL in GC haven’t been rarely seen. Presently, in-vivo and ex-vivo experiments were implemented to examine the PURPL-miR-137-ZBTB7A-PI3K-AKT-NF-κB regulatory axis in GC. Our statistics revealed that PURPL presented a high expression in GC tissues and cell lines. PURPL overexpression remarkably exacerbated colony formation, migration, and invasion and repressed apoptosis in GC cells (AGS and MNK-45). In-vivo experiments also corroborated that cell growth was boosted by PURPL up-regulation. Mechanistic investigations verified that PURPL interacted with miR-137 and lowered its profile in GC cell lines. miR-137 overexpression or ZBTB7A knockdown upended the oncogenic function mediated by PURPL. PURPL initiated the PI3K/AKT/NF-κB pathway. PI3K and NF-κB inhibition impaired the promoting impact on GC cells elicited by PURPL overexpression and contributed to PURPL down-regulation. These findings disclosed that PURPL serves as an oncogene in the context of GC via miR-137-ZBTB7A-PI3K-AKT-NF-κB axis modulation.