HOXD Antisense Growth-Associated Long Noncoding RNA Promotes Triple-Negative Breast Cancer Progression by Activating Wnt Signaling Pathway

HAGLR, A Long Non-coding RNA of Potential Tumor Suppressive Function in Clear Cell Renal Cell Carcinoma: Diagnostic and Prognostic Implications

Research works suggested the role of long non-coding RNAs (lncRNAs) in pathogenesis of clear cell renal cell carcinoma (ccRCC). lncRNA HAGLR is studied in several malignancies, but not in ccRCC. From The Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) dataset, we analyzed molecular alterations of HAGLR and constructed a competitive endogenous RNA (ceRNA) network with related miRNAs and mRNAs. Gene Ontology analysis was done to identify important pathways enriched with HAGLR recovered mRNAs. Clinical importance of HAGLR and related mRNAs was assessed and, the impact of selected mRNA-encoding genes on tumor immune infiltration was studied using TIMER. HAGLR expression was reduced in ccRCC than in normal kidneys, and correlated significantly with gene promoter methylation. Low HAGLR level in tumors showed diagnostic potency, and was associated with clinicopathological parameters (stage/grade/metastasis) and poor patient survival. The HAGLR-associated ceRNA network constituted 13 miRNAs and 23 mRNAs differentially expressed in the TCGA-KIRC dataset. From HAGLR recovered mRNA-encoding genes, we developed a 5-gene (PAQR5, ARHGAP24, HABP4, PDLIM5, and RPS6KA2) prognostic signature in the training dataset and validated it in testing as well as entire datasets. The expression level of signature genes showed negative correlation with tumor infiltration of immune cells having adverse impact on ccRCC prognosis and also with tumor derived chemokines facilitating the infiltration. In conclusion, HAGLR seemed to play a tumor suppressive role in ccRCC. HAGLR and associated gene signature may have implementation in improving existing prognostic measure and developing effective immunotherapeutic strategies for ccRCC.

Exploring the clinical potential of circulating LncRNAs in breast cancer: insights into primary signaling pathways and therapeutic interventions

Breast cancer (BC) occupies the top spot among women on a global scale. The tumor has a significant degree of heterogeneity, displaying a notable prevalence of medication resistance, recurrence, and metastasis, rendering it one of the most lethal forms of malignant neoplasms. The timely identification, ongoing evaluation of therapeutic interventions, and accurate prediction of outcomes play crucial roles in determining the overall survival rates of women with BC. Nevertheless, the absence of precise biomarkers remains a significant determinant impacting the overall well-being and both the physical and emotional health of BC patients. Long noncoding RNA (lncRNA) exerts regulatory control over several genes and signaling pathways, hence assuming crucial roles in the development of neoplastic growth. Recently, research has indicated that the atypical expression of circulating lncRNAs in various biological bodily fluids has a noteworthy impact on the early detection, pathological categorization, staging, monitoring of therapy outcomes, and evaluation of prognosis in cases of BC. This article aims to assess the potential clinical utility of circulating lncRNAs in the context of BC focusing on specific primary signaling pathways; Wnt/β-catenin, Notch, TGF-β, and hedgehog (Hh), in addition to some therapeutic interventions.

Knockdown of LncRNA-HAGLR restrains the viability and motility of pancreatic cancer via miR-625-5p/TAF15 axis in vitro and in vivo

Dysregulation of long non-coding RNAs (lncRNAs) has been strongly involved to the development of pancreatic cancer (PC). However, the potential mechanisms by which lncRNA regulate PC development still need to be further explored. We attempted to elucidate the functional role and regulatory mechanism of lncRNA HAGLR on PC progression in vitro and vivo. RT-qPCR, Western blot, RNA pull-down, luciferase reporter assay, RNA immunoprecipitation assay, CCK-8 assay, EdU assay, flow cytometry, transwell assay and xenograft tumor experiment were performed in this study. We found that the expressions of HAGLR and TAF15 were increased in PC tissues and cells. HAGLR silencing restrained the PC cell growth and invasion, but induced cell apoptosis. Moreover, HAGLR targeted miR-625-5p to modulate the expression of TAF15. HAGLR overexpression partially eliminated the suppressive effect of TAF15 depletion on PC cell growth and the stimulative effect on apoptosis. In vivo assays showed that HAGLR knockdown inhibited PC cell growth by regulating the TAF15 expression. These findings suggest HAGLR could facilitate PC cell malignant behaviors through regulating the TAF15 expression, demonstrating that HAGLR might be a valuable target for the PC treatment.

LncRNA HAGLR regulates gastric cancer progression by regulating the miR-20a-5p/E2F1 axis

BACKGROUND

Gastric cancer (GC) stands as a prevalent and challenging malignancy within the gastrointestinal tract. The potential of long non-coding RNAs (lncRNAs) as biomarkers and therapeutic targets in oncology has garnered immense research interest. This study aims to elucidate the relevance, biological roles, and mechanistic pathways of LncRNA HAGLR in the context of GC.

METHODS

The assessments of cell proliferation, migration, and invasion were executed using CCK-8, wound healing, and Transwell assays. The interactions between HAGLR, miR-20a-5p, and E2F1 were appraised through luciferase reporter assays, fluorescence in situ hybridization (FISH), and RNA immunoprecipitation (RIP). A tumor xenograft model provided in vivo validation for in vitro findings.

RESULTS

Elevated levels of HAGLR in GC cells and tissue specimens were linked to worse patient outcomes. The inhibition of HAGLR led to a decrease in GC cell proliferation, migration, and invasion, whereas its activation prompted contrary effects. The impact of HAGLR on cell migration and invasion was notably associated with epithelial-mesenchymal transition (EMT). Through bioinformatics, luciferase reporter assays, FISH, RIP, and Western blot analyses, it was revealed that HAGLR acts as a molecular sponge for miR-20a-5p, consequently augmenting E2F1 levels.

CONCLUSIONS

The data suggest that the HAGLR/miR-20a-5p/E2F1 regulatory cascade is implicated in GC pathogenesis, offering a novel therapeutic avenue for GC management.

SRSF1 inhibits ferroptosis and reduces cisplatin chemosensitivity of triple-negative breast cancer cells through the circSEPT9/GCH1 axis

Cisplatin (DDP) is a commonly used chemotherapeutic agent for triple negative breast cancer (TNBC), but its efficacy can be limited by chemoresistance. This study aimed to explore the functional mechanism of SR-rich splicing factor 1 (SRSF1) in DDP chemosensitivity of TNBC cells. Levels of SRSF1, circular RNA septin 9 (circSEPT9), and GTP cyclohydrolase-1 (GCH1) in TNBC cells, DDP-resistant cells, and normal cells were determined. Cell viability, half-maximal inhibitory concentration (IC50) value, and proliferation were evaluated. Ferroptosis was determined by assay kits (ferric ion/ROS/MDA/GSH) and Western blot assay (SLC7A11/ACSL4). The genetic binding was analyzed by RNA immunoprecipitation and RNA pull-down assays. SRSF1, circSEPT9, and GCH1 were upregulated in TNBC cells. SRSF1 downregulation reduced IC50 to DDP of parent and drug-resistant TNBC cells and inhibited cell viability and proliferation, meanwhile, the downregulation reduced GSH/SLC7A11 levels while elevated ferric ion/ROS/MDA/ACSL4 levels, promoting ferroptosis. SRSF1 bound to and upregulated circSEPT9 and circSEPT9 blocked the ubiquitination of GCH1, thereby increasing GCH1 protein level. Overexpression of circSEPT9 and GCH1 attenuated the DDP chemosensitivity of TNBC cells by inhibiting ferroptosis. This study is the first to report the role of SRSF1 inhibitors combined with chemotherapy in TNBC, which provides a promising strategy for the treatment of TNBC. SIGNIFICANCE: Cisplatin (DDP) is a commonly used chemotherapeutic agent for triple negative breast cancer (TNBC), but its efficacy can be limited by chemoresistance. This study aimed to unravel the molecular mechanism of SR-rich splicing factor 1 (SRSF1) in DDP chemosensitivity of TNBC cells.

LncRNA HAGLR May Aggravate Melanoma Malignancy Via miR-4644/ASB11 Pathway

In this study, we aimed to assess the biological functions of HAGLR and its underlying mechanisms in melanoma. HAGLR and ASB11 were knocked down by transfection with the corresponding siRNAs. Meanwhile, miR-4644 was downregulated using the miR-4644 inhibitor treatment. The target interactions among the three molecules were demonstrated using dual-luciferase reporter and RNA immunoprecipitation assays. The levels of HAGLR, miR-4644, and ASB11 in melanoma cells and tissues were assessed using quantitative real‑time PCR and western blotting. The functions and mechanisms underlying HAGLR action in melanoma progression were examined using Cell Counting Kit-8, Transwell, Caspase-3 activity, and xenograft tumor formation assays. HAGLR and ASB11 expression were elevated, whereas that of miR-4644 was downregulated in melanoma cells and tissues. The viability and migration of melanoma cells (A875 and A375) were markedly suppressed by the knockdown of HAGLR and ASB11 but promoted following miR-4644 inhibitor transfection. In contrast, apoptosis showed the opposite trend. In vivo, tumor weight declined considerably with downregulation of HAGLR. Mechanistically, HAGLR sponges miR-4644, increasing the levels of ASB11 and further aggravating melanoma. It latter negatively targets ASB11 in melanoma cells. Hence, the HAGLR-miR-4644-ASB11 axis may be a promising target for melanoma treatment.

Crosstalk between Long Non-Coding RNA and Spliceosomal microRNA as a Novel Biomarker for Cancer

Non-coding RNAs (ncRNAs) play diverse roles in regulating cellular processes and have been implicated in pathological conditions, including cancer, where interactions between ncRNAs play a role. Relevant here are (i) microRNAs (miRNAs), mainly known as negative regulators of gene expression in the cytoplasm. However, identification of miRNAs in the nucleus suggested novel nuclear functions, and (ii) long non-coding RNA (lncRNA) regulates gene expression at multiple levels. The recent findings of miRNA in supraspliceosomes of human breast and cervical cancer cells revealed new candidates of lncRNA targets. Here, we highlight potential cases of crosstalk between lncRNA and supraspliceosomal miRNA expressed from the same genomic region, having complementary sequences. Through RNA:RNA base pairing, changes in the level of one partner (either miRNA or lncRNA), as occur in cancer, could affect the level of the other, which might be involved in breast and cervical cancer. An example is spliceosomal mir-7704 as a negative regulator of the oncogenic lncRNA HAGLR. Because the expression of spliceosomal miRNA is cell-type-specific, the list of cis-interacting lncRNA:spliceosomal miRNA presented here is likely just the tip of the iceberg, and such interactions are likely relevant to additional cancers. We thus highlight the potential of lncRNA:spliceosomal miRNA interactions as novel targets for cancer diagnosis and therapies.

Lycorine weakens tamoxifen resistance of breast cancer via abrogating HAGLR-mediated epigenetic suppression on VGLL4 by DNMT1

Much is known about the significance of lycorine, a natural alkaloid, in combating various types of cancer, including breast cancer (BC), but whether it participates in regulating tamoxifen (TAM) resistance and its underlying mechanism remain to be elucidated. Tamoxifen-resistant (TAMR) BC cells were first established by continuously exposed to increasing concentrations of TAM. Levels of targeted gene including HOXD antisense growth-associated lncRNA (HAGLR) and Vestigial like family member 4 (VGLL4) were analyzed by qRT-PCR and western blot, respectively. Cell proliferation ability was assessed by MTT and EdU assays. Flow cytometry was carried out to evaluate the apoptosis. VGLL4 promoter methylation was examined using methylation specific PCR (MSP). The role of HAGLR acting on the expression of VGLL4 via DNA hypermethylation was confirmed by RNA immunoprecipitation (RIP). Here, we reported that lycorine administration reduced the survival ratio of TAMR BC cells, decreased the IC₅₀ of TAM, and strengthened TAM-induced apoptosis. HAGLR, observed to be highly expressed in TAMR BC cells, was identified to be a downstream effector of lycorine, of which overexpression abolished lycorine-mediated TAMR inhibition. VGLL4 served as a target of HAGLR in regulating lycorine-mediated suppression on tamoxifen resistance of TAMR BC cells. Mechanistically, HAGLR epigenetically suppressed VGLL4 expression via DNA methyltransferase 1 (DNMT1)-mediated DNA hypermethylation. Taken together, our data highlights the pivotal role of lycorine in TAM resistance of BC, which may provide a potential agent for improving the effectiveness and efficacy of BC resistance.

Feiyanning formula modulates the molecular mechanism of osimertinib resistance in lung cancer by regulating the Wnt/β-catenin pathway

Feiyanning Formula (FYN), a Chinese herbal formula derived from summarized clinical experience, is proven to have anti-tumor effects in lung cancer patients. Osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), can improve progression-free survival and overall survival of patients but drug resistance is inevitable. The current study evaluated the effects of FYN in osimertinib-resistant HCC827OR and PC9OR cells. FYN preferentially inhibited the proliferation and migration of HCC827OR and PC9OR cells. Moreover, FYN and osimertinib exhibited synergistic inhibitory effects on proliferation and migration. Real-time qPCR (RT-qPCR) and western blotting results indicated that FYN downregulated gene and protein levels of GSK3β and SRFS1, which are enriched in the Wnt/β-catenin pathway. Besides, FYN inhibited tumor growth and exhibited synergistic effects with osimertinib in vivo. Collectively, the results suggested that FYN exerted an anti-osimertinib resistance effect via the Wnt/β-catenin pathway.

Close interactions between lncRNAs, lipid metabolism and ferroptosis in cancer

Abnormal lipid metabolism including synthesis, uptake, modification, degradation and transport has been considered a hallmark of malignant tumors and contributes to the supply of substances and energy for rapid cell growth. Meanwhile, abnormal lipid metabolism is also associated with lipid peroxidation, which plays an important role in a newly discovered type of regulated cell death termed ferroptosis. Long noncoding RNAs (lncRNAs) have been proven to be associated with the occurrence and progression of cancer. Growing evidence indicates that lncRNAs are key regulators of abnormal lipid metabolism and ferroptosis in cancer. In this review, we mainly summarized the mechanism by which lncRNAs regulate aberrant lipid metabolism in cancer, illustrated that lipid metabolism can also influence the expression of lncRNAs, and discussed the mechanism by which lncRNAs affect ferroptosis. A comprehensive understanding of the interactions between lncRNAs, lipid metabolism and ferroptosis could help us to develop novel strategies for precise cancer treatment in the future.