m6A reader HNRNPA2B1 destabilization of ATG4B regulates autophagic activity, proliferation and olaparib sensitivity in breast cancer

LINC00645 inhibits renal cell carcinoma progression by interacting with HNRNPA2B1 to regulate the ROCK1 mRNA stability

The lncRNA plays an important role in tumorigenesis and the progression of renal cell carcinoma (RCC). LINC00645 is one of the most different expressed lncRNA between RCC and normal renal tissue. However, the regulatory mechanism of LINC00645 in RCC remains unknown. Our results indicated that LINC00645 inhibited RCC proliferation, migration, and invasion. Mechanistically, HNRNPA2B1 directly bound to ROCK1 mRNA and strengthened its stability. LINC00645 competitively bound to the RRM1 domain, which is responsible for interacting with ROCK1 mRNA, reducing ROCK1 mRNA level by affecting posttranscriptional destabilization. The expression of LINC00645 was significantly reduced in RCC cells, significantly upregulating ROCK1 by abolishing the interaction with HNRNPA2B1, finally promoting RCC proliferation, migration, and invasion. Moreover, RCC cells with lower LINC00645 expression were more sensitive to the ROCK1 inhibitor Y-27632. Our study indicates that decreased expression of LINC00645 promotes the RCC progression via HNRNPA2B1/ROCK1 axis, providing a promising treatment strategy for RCC patients with decreased LINC00645 expression.

HNRNPC promotes estrogen receptor-positive breast cancer cell cycle by stabilizing WDR77 mRNA in an m6A-dependent manner

Breast cancer has become the most commonly diagnosed cancer. Heterogeneous nuclear ribonucleoprotein C (HNRNPC), a reader of N6-methyladenosine (m6A), has been observed to be upregulated in various types of cancer. Nevertheless, the role of HNRNPC in breast cancer and whether it is regulated by m6A modification deserve further investigation. The expression of HNRNPC in breast cancer was examined by quantitative real-time polymerase chain reaction and western blot analysis. RNA immunoprecipitation was performed to validate the binding relationships between HNRNPC and WD repeat domain 77 (WDR77). The effects of HNRNPC and m6A regulators on WDR77 were investigated by actinomycin D assay. The experiments in vivo were conducted in xenograft models. In this research, we found that HNRNPC was highly expressed in breast cancer, and played a crucial role in cell growth, especially in the luminal subtype. HNRNPC could combine and stabilize WDR77 mRNA. WDR77 successively drove the G1/S phase transition in the cell cycle and promoted cell proliferation. Notably, this regulation axis was closely tied to the m6A modification status of WDR77 mRNA. Overall, a critical regulatory mechanism was identified, as well as promising targets for potential treatment strategies for luminal breast cancer.

N6-methyladenosine (m6A) in cancer stem cell: From molecular mechanisms to therapeutic implications

The emergence of drug resistance and metastasis has long been a difficult problem for cancer treatment. Recent studies have shown that cancer stem cell populations are key factors in the regulation of cancer aggressiveness, relapse and drug resistance. Cancer stem cell (CSC) populations are highly plastic and self-renewing, giving them unique metabolic, metastatic, and chemotherapy resistance properties. N6-methyladenosine (m6A) is the most abundant internal modification of mRNA and is involved in a variety of cell growth and development processes, including RNA transcription, alternative splicing, degradation, and translation. It has also been linked to the development of various cancers. At present, the important role of m6A in tumour progression is gradually attracting attention, especially in the tumour stemness regulation process. Abnormal m6A modifications regulate tumour metastasis, recurrence and drug resistance. This paper aims to explore the regulatory mechanism of m6A in CSCs and clinical therapy, clarify its regulatory network, and provide theoretical guidance for the development of clinical targets and improvement of therapeutic effects.

Role of Heterogeneous Nuclear Ribonucleoproteins in the Cancer-Immune Landscape

Cancer remains the second leading cause of death, accounting for approximately 20% of all fatalities. Evolving cancer cells and a dysregulated immune system create complex tumor environments that fuel tumor growth, metastasis, and resistance. Over the past decades, significant progress in deciphering cancer cell behavior and recognizing the immune system as a hallmark of tumorigenesis has been achieved. However, the underlying mechanisms controlling the evolving cancer-immune landscape remain mostly unexplored. Heterogeneous nuclear ribonuclear proteins (hnRNP), a highly conserved family of RNA-binding proteins, have vital roles in critical cellular processes, including transcription, post-transcriptional modifications, and translation. Dysregulation of hnRNP is a critical contributor to cancer development and resistance. HnRNP contribute to the diversity of tumor and immune-associated aberrant proteomes by controlling alternative splicing and translation. They can also promote cancer-associated gene expression by regulating transcription factors, binding to DNA directly, or promoting chromatin remodeling. HnRNP are emerging as newly recognized mRNA readers. Here, we review the roles of hnRNP as regulators of the cancer-immune landscape. Dissecting the molecular functions of hnRNP will provide a better understanding of cancer-immune biology and will impact the development of new approaches to control and treat cancer.