TGF-β/SMAD Pathway Is Modulated by miR-26b-5p: Another Piece in the Puzzle of Chronic Lymphocytic Leukemia Progression

miRNA Biology in Chronic Lymphocytic Leukemia

microRNAs (miRNAs) are a class of small non-coding RNAs that play a crucial regulatory role in fundamental biological processes and have been implicated in various diseases, including cancer. The first evidence of the cancer-related function of miRNAs was discovered in chronic lymphocytic leukemia (CLL) in the early 2000s. Alterations in miRNA expression have since been shown to strongly influence the clinical course, prognosis, and response to treatment in patients with CLL. Therefore, the identification of specific miRNA alterations not only enhances our understanding of the molecular mechanisms underlying CLL but also holds promise for the development of novel diagnostic and therapeutic strategies. This review aims to provide a comprehensive summary of the current knowledge and recent insights into miRNA dysregulation in CLL, emphasizing its pivotal roles in disease progression, including the development of the lethal Richter syndrome, and to provide an update on the latest translational research in this field.

Molecular detection of exosomal miRNAs of blood serum for prognosis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer affecting people. The discovery of new, non-invasive, specific, and sensitive molecular biomarkers for CRC may assist in the diagnosis and support therapeutic decision making. Exosomal miRNAs have been demonstrated in carcinogenesis and CRC development, which makes these miRNAs strong biomarkers for CRC. Deep sequencing allows a robust high-throughput informatics investigation of the types and abundance of exosomal miRNAs. Thus, exosomal miRNAs can be efficiently examined as diagnostic biomarkers for disease screening. In the present study, a number of 660 mature miRNAs were detected in patients diagnosed with CRC at different stages. Of which, 29 miRNAs were differentially expressed in CRC patients compared with healthy controls. Twenty-nine miRNAs with high abundance levels were further selected for subsequent analysis. These miRNAs were either highly up-regulated (e.g., let-7a-5p, let-7c-5p, let-7f-5p, let-7d-3p, miR-423-5p, miR-3184-5p, and miR-584) or down-regulated (e.g., miR-30a-5p, miR-99-5p, miR-150-5p, miR-26-5p and miR-204-5p). These miRNAs influence critical genes in CRC, leading to either tumor growth or suppression. Most of the reported diagnostic exosomal miRNAs were shown to be circulating in blood serum. The latter is a novel miRNA that was found in exosomal profile of blood serum. Some of the predicted target genes of highly expressed miRNAs participate in several cancer pathways, including CRC pathway. These target genes include tumor suppressor genes, oncogenes and DNA repair genes. Main focus was given to multiple critical signaling cross-talking pathways including transforming growth factor β (TGFβ) signaling pathways that are directly linked to CRC. In conclusion, we recommend further analysis in order to experimentally confirm exact relationships between selected differentially expressed miRNAs and their predicted target genes and downstream functional consequences.

Evaluation of MicroRNA as Minimal Residual Disease in Leukemia: Diagnostic and Prognostic Approach: A Review

Various factors are effective in the development of minimal residual disease (MRD), one of which is MicroRNAs (miRNAs). miRNAs and their dysfunction in gene expression have influential role in the pathogenesis of leukemia. Nowadays, treatments that lead to the suppression or replacement of miRNAs have been developed. Focusing on the role of miRNAs in managing the treatment of leukemia, in this review article we have investigated the miRNAs and signaling pathways involved in the process of apoptosis and cell proliferation, as well as miRNAs with oncogenic function in malignant leukemia cells. Among the studied miRNAs, miR-99a, and miR-181a play an essential role in apoptosis, proliferation and oncogenesis via AKT, MAPK, RAS, and mTOR signaling pathways. miR-223 and miR-125a affect apoptosis and oncogenesis via Wnt/B-catenin, PTEN/PI3K, and STAT5/AKT/ERK/Src signaling pathways. miR-100 also affects both apoptosis and oncogenesis; it acts via IGF1 and mTOR signaling pathways.

SMAD Proteins in TGF-β Signalling Pathway in Cancer: Regulatory Mechanisms and Clinical Applications

Suppressor of mother against decapentaplegic (SMAD) family proteins are central to one of the most versatile cytokine signalling pathways in metazoan biology, the transforming growth factor-β (TGF-β) pathway. The TGF-β pathway is widely known for its dual role in cancer progression as both an inhibitor of tumour cell growth and an inducer of tumour metastasis. This is mainly mediated through SMAD proteins and their cofactors or regulators. SMAD proteins act as transcription factors, regulating the transcription of a wide range of genes, and their rich post-translational modifications are influenced by a variety of regulators and cofactors. The complex role, mechanisms, and important functions of SMAD proteins in tumours are the hot topics in current oncology research. In this paper, we summarize the recent progress on the effects and mechanisms of SMAD proteins on tumour development, diagnosis, treatment and prognosis, and provide clues for subsequent research on SMAD proteins in tumours.

Small RNA Profiling in an HTLV-1-Infected Patient with Acute Adult T-Cell Leukemia-Lymphoma at Diagnosis and after Maintenance Therapy: A Case Study

Small RNAs (sRNAs) are epigenetic regulators of essential biological processes associated with the development and progression of leukemias, including adult T-cell leukemia/lymphoma (ATLL) caused by human T-cell lymphotropic virus type 1 (HTLV-1), an oncogenic human retrovirus originally discovered in a patient with adult T-cell leukemia/lymphoma. Here, we describe the sRNA profile of a 30-year-old woman with ATLL at the time of diagnosis and after maintenance therapy with the aim of correlating expression levels with response to therapy.

Identification of lncRNA, miRNA and mRNA expression profiles and ceRNA Networks in small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) is a highly lethal malignant tumor. It accounts for approximately 15% of newly diagnosed lung cancers. Long non-coding RNAs (lncRNAs) can regulate gene expression and contribute to tumorigenesis through interactions with microRNAs (miRNAs). However, there are only a few studies reporting the expression profiles of lncRNAs, miRNAs, and mRNAs in SCLC. Also, the role of differentially expressed lncRNAs, miRNAs, and mRNAs in relation to competitive endogenous RNAs (ceRNA) network in SCLC remain unclear.

RESULTS

In the present study, we first performed next generation sequencing (NGS) with six pairs of SCLC tumors and adjacent non-cancerous tissues obtained from SCLC patients. Overall, 29 lncRNAs, 48 miRNAs, and 510 mRNAs were found to be differentially expressed in SCLC samples (|log₂[fold change] |> 1; P < 0.05). Bioinformatics analysis was performed to predict and construct a lncRNA-miRNA-mRNA ceRNA network, which included 9 lncRNAs, 11 miRNAs, and 392 mRNAs. Four up-regulated lncRNAs and related mRNAs in the ceRNA regulatory pathways were selected and validated by quantitative PCR. In addition, we examined the role of the most upregulated lncRNA, TCONS_00020615, in SCLC cells. We found that TCONS_00020615 may regulate SCLC tumorigenesis through the TCONS_00020615-hsa-miR-26b-5p-TPD52 pathway.

CONCLUSIONS

Our study provided the comprehensive analysis of the expression profiles of lncRNAs, miRNAs, and mRNAs of SCLC tumors and adjacent non-cancerous tissues. We constructed the ceRNA networks which may provide new evidence for the underlying regulatory mechanism of SCLC. We also found that the lncRNA TCONS_00020615 may regulate the carcinogenesis of SCLC.