LncRNA FAL1 Upregulates SOX4 by Downregulating miR-449a to Promote the Migration and Invasion of Cervical Squamous Cell Carcinoma (CSCC) Cells

Molecular Crosstalk by miR-449a and miR-34b in endometrial and ovarian cancer cells in vitro

AIMS

Endometrial and ovarian cancers, the sixth and eighth most prevalent cancers in women globally, account for nearly 8% of all new female cancer cases annually. MicroRNAs (miRNAs) have emerged as a promising field in cancer treatment, offering new avenues for targeted therapies and diagnostic tools. Recent miRNA-based cancer research has uncovered various miRNAs commonly dysregulated in cancer and which possess tumor-suppressive functions. These miRNAs influence genes crucial for cellular differentiation, proliferation, apoptosis, and metabolism.

MAIN METHODS

In the present study, the researchers investigated the effect of dysregulation of two such miRNAs, miR-449a and miR-34b, on the oncogenes involved in the progression of endometrial and ovarian cancer using the respective RL95-2 and SKOV3 cell lines. The transcriptional gene expression analysis was done by Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR).

KEY FINDINGS

It was found that the overexpression of miR-449a and miR-34b downregulated HIF-1α, VEGF, c-Myc, COX-2, and TNF-α while upregulating TP53 in both cancer types. Conversely, inhibiting these miRNAs increased the levels of HIF-1α, VEGF, c-Myc, COX-2, and TNF-α, and decreased TP53. However, co-transfection with both mimic and inhibitor had varying effects.

SIGNIFICANCE

The study demonstrated that these miRNAs could influence critical processes such as angiogenesis, proliferation, inflammation, tumorigenesis, and apoptosis in cancer cells, highlighting their potential as therapeutic targets. However, the varied effects observed with the co-transfection of mimics and inhibitors suggest a complex interplay that requires further investigation.

A Critical Review on microRNAs as Prognostic Biomarkers in Laryngeal Carcinoma

During the past decade, a vast number of studies were dedicated to unravelling the obscurities of non-coding RNAs in all fields of the medical sciences. A great amount of data has been accumulated, and consequently a natural need for organization and classification in all subfields arises. The aim of this review is to summarize all reports on microRNAs that were delineated as prognostic biomarkers in laryngeal carcinoma. Additionally, we attempt to allocate and organize these molecules according to their association with key pathways and oncogenes affected in laryngeal carcinoma. Finally, we critically analyze the common shortcomings and biases of the methodologies in some of the published papers in this area of research. A literature search was performed using the PubMed and MEDLINE databases with the keywords "laryngeal carcinoma" OR "laryngeal cancer" AND "microRNA" OR "miRNA" AND "prognostic marker" OR "prognosis". Only research articles written in English were included, without any specific restrictions on study type. We have found 43 articles that report 39 microRNAs with prognostic value associated with laryngeal carcinoma, and all of them are summarized along with the major characteristics and methodology of the respective studies. A second layer of the review is structural analysis of the outlined microRNAs and their association with oncogenes and pathways connected with the cell cycle (p53, CCND1, CDKN2A/p16, E2F1), RTK/RAS/PI3K cascades (EGFR, PI3K, PTEN), cell differentiation (NOTCH, p63, FAT1), and cell death (FADD, TRAF3). Finally, we critically review common shortcomings in the methodology of the papers and their possible effect on their results.

miR-449a: A Promising Biomarker and Therapeutic Target in Cancer and Other Diseases

In the regulation of gene expression, epigenetic factors like non-coding RNAs (ncRNAs) play an equal role in genetics. The role of microRNAs (miRNAs), which are members of the ncRNA family, in post-transcriptional gene regulation is well-documented and has important implications for both normal and abnormal biological processes, such as angiogenesis, proliferation, survival, and apoptosis. The purpose of this study was to synthesize previous research on miR-449a by analyzing published results from various databases, as there have been a number of investigations on miR-449's potential involvement in the development of human disorders. Based on our findings, miR-449 is strongly dysregulated in a wide range of diseases, from various cancers to cardiovascular diseases, cognitive impairments, and respiratory diseases, and it may play a pivotal role in the development of these problems. In addition, miR-449a functions as a crucial regulator of the expression of several well-known genes, including E2F-3, BCL2, NOTCH1, and SOX4. This, in turn, modulates various pathways and processes related to cancer, including Notch, PI3K, and TGF-β, and contributes to the improvement of cancer drug sensitivity. Curiously, abnormalities in the expression of this miRNA may serve as diagnostic or prognostic indicators for distinguishing between healthy people and patients or to evaluate the survival rates for specific disorders. This article provides a synopsis of the current understanding of miR-449a's role in human disease development through its regulation of gene expression and the biological processes related to these genes and their linked processes. In addition, we have covered the topic of miR-449a's potential as a clinical feature (diagnosis and prognosis) indicator for a range of disorders, both neoplastic and non-neoplastic. In general, our goal was to gain a thorough comprehension of the numerous functions of miR-449a in different disorders.

New insights on the interaction between m6A modification and non-coding RNA in cervical squamous cell carcinoma

BACKGROUND

N6-Methyladenosine (m6A) and long non-coding RNAs (lncRNAs) are both crucial regulators in human cancer growth and metastasis. However, their regulation on cervical squamous cell carcinoma (CSCC) is largely unclear. The present study aimed to explore the role of m6A-associated lncRNAs in CSCC.

METHODS

We screened the expression of methylation modification-related enzymes in CECC samples from TCGA. The qRT-PCR was used to detect METTL3 and lncRNA METTL4-2 expression. The biological activities of METTL3 in CSCC cells were evaluated by CCK-8, colony formation, transwell, wound healing, and xenograft tumor assays, respectively. The SRAMP tool was used to screen m6A modification sites of METTL4-2. Finally, the quantitative analysis of m6A modification was carried out by MeRIP.

RESULTS

METTL3 expression was upregulated in CSCC cells and tissues. Biological function and function loss analysis indicated that METTL3 promoted the migration and proliferation of CSCC cells. In addition, METTL3 promoted CSCC tumor growth in vivo. Mechanically, METTL3 installed the m6A modification and enhanced METTL4-2 transcript stability to increase its expression. Meanwhile, the m6A "reader" YTHDF1 recognized METTL4-2 installed by METTL3 and facilitated the translation of METTL4-2.

CONCLUSIONS

In conclusion, our study highlights the function and mechanism of METTL3-induced METTL4-2 in CSCC. These findings support that METTL3-stabilized METTL4-2 promoted CSCC progression via a m6A-dependent modality, which provides new insights into therapeutic strategies for CSCC.

Upregulation of Atypical Cadherin FAT1 Promotes an Immunosuppressive Tumor Microenvironment via TGF-β

FAT atypical cadherin 1 (FAT1) promotes glioblastoma (GBM) by promoting protumorigenic inflammatory cytokine expression in tumor cells. However, tumors also have an immunosuppressive microenvironment maintained by mediators such as transforming growth factor (TGF)-β cytokines. Here, we have studied the role of FAT1 in tumor immune suppression. Our preliminary TIMER2.0 analysis of The Cancer Genome Atlas (TCGA) database revealed an inverse correlation of FAT1 expression with infiltration of tumor-inhibiting immune cells (such as monocytes and T cells) and a positive correlation with tumor-promoting immune cells [such as myeloid-derived suppressor cells (MDSCs)] in various cancers. We have analyzed the role of FAT1 in modulating the expression of TGF-β1/2 in resected human gliomas, primary glioma cultures, and other cancer cell lines (U87MG, HepG2, Panc-1, and HeLa). Positive correlations of gene expression of FAT1 and TGF-β1/2 were observed in various cancers in TCGA, Glioma Longitudinal Analysis Consortium (GLASS), and Chinese Glioma Genome Atlas (CGGA) databases. Positive expression correlations of FAT1 were also found with TGF-β1/2 and Serpine1 (downstream target) in fresh-frozen GBM samples using q-PCR. siRNA-mediated FAT1 knockdown in cancer cell lines and in primary cultures led to decreased TGF-β1/2 expression/secretion as assessed by q-PCR, Western blotting, and ELISA. There was increased chemotaxis (transmigration) of THP-1 monocytes toward siFAT1-transfected tumor cell supernatant as a consequence of decreased TGF-β1/2 secretion. Reduced TGF-β1 expression was also observed in THP-1 cultured in conditioned media from FAT1-depleted glioma cells, thus contributing to immune suppression. In U87MG cells, decreased TGF-β1 upon FAT1 knockdown was mediated by miR-663a, a known modulator. FAT1 expression was also observed to correlate positively with the expression of surrogate markers of MDSCs [programmed death ligand-1 (PD-L1), PD-L2, and interleukin (IL)-10] in glioma tumors, suggesting a potential role of FAT1 in MDSC-mediated immunosuppression. Hence, our findings elaborate contributions of FAT1 to immune evasion, where FAT1 enables an immunosuppressive microenvironment in GBM and other cancers via TGF-β1/2.

Detailed characterization of the transcriptome of single B cells in mantle cell lymphoma suggesting a potential use for SOX4

Mantle cell lymphoma (MCL) is a malignancy arising from naive B lymphocytes with common bone marrow (BM) involvement. Although t(11;14) is a primary event in MCL development, the highly diverse molecular etiology and causal genomic events are still being explored. We investigated the transcriptome of CD19⁺ BM cells from eight MCL patients at single-cell level. The transcriptomes revealed marked heterogeneity across patients, while general homogeneity and clonal continuity was observed within the patients with no clear evidence of subclonal involvement. All patients were SOX11⁺CCND1⁺CD20⁺. Despite monotypic surface immunoglobulin (Ig) κ or λ protein expression in MCL, 10.9% of the SOX11 + malignant cells expressed both light chain transcripts. The early lymphocyte transcription factor SOX4 was expressed in a fraction of SOX11 + cells in two patients and co-expressed with the precursor lymphoblastic marker, FAT1, in a blastoid case, suggesting a potential prognostic role. Additionally, SOX4 was found to identify non-malignant SOX11^– pro-/pre-B cell populations. Altogether, the observed expression of markers such as SOX4, CD27, IgA and IgG in the SOX11⁺ MCL cells, may suggest that the malignant cells are not fixed in the differentiation state of naïve mature B cells, but instead the patients carry B lymphocytes of different differentiation stages.