Micropeptide MIAC inhibits the tumor progression by interacting with AQP2 and inhibiting EREG/EGFR signaling in renal cell carcinoma

Micropeptides: potential treatment strategies for cancer

Some noncoding RNAs (ncRNAs) carry open reading frames (ORFs) that can be translated into micropeptides, although noncoding RNAs (ncRNAs) have been previously assumed to constitute a class of RNA transcripts without coding capacity. Furthermore, recent studies have revealed that ncRNA-derived micropeptides exhibit regulatory functions in the development of many tumours. Although some of these micropeptides inhibit tumour growth, others promote it. Understanding the role of ncRNA-encoded micropeptides in cancer poses new challenges for cancer research, but also offers promising prospects for cancer therapy. In this review, we summarize the types of ncRNAs that can encode micropeptides, highlighting recent technical developments that have made it easier to research micropeptides, such as ribosome analysis, mass spectrometry, bioinformatics methods, and CRISPR/Cas9. Furthermore, based on the distribution of micropeptides in different subcellular locations, we explain the biological functions of micropeptides in different human cancers and discuss their underestimated potential as diagnostic biomarkers and anticancer therapeutic targets in clinical applications, information that may contribute to the discovery and development of new micropeptide-based tools for early diagnosis and anticancer drug development.

A novel lncRNA-hidden polypeptide regulates malignant phenotypes and pemetrexed sensitivity in A549 pulmonary adenocarcinoma cells

The advance of high-throughput sequencing enhances the discovery of short ORFs embedded in long non-coding RNAs (lncRNAs). Here, we uncovered the production and biological activity of lncRNA-hidden polypeptides in lung adenocarcinoma (LUAD). In the present study, bioinformatics was used to screen the lncRNA-hidden polypeptides in LUAD. Analysis of protein expression was done by western blot or immunofluorescence assay. The functions of the polypeptide were determined by detecting its effects on cell viability, proliferation, migration, invasion, and pemetrexed (PEM) sensitivity. The protein interactors of the polypeptide were analyzed by mass spectrometry after Co-immunoprecipitation (Co-IP) assay. The results showed that the lncRNA LINC00954 was confirmed to encode a novel polypeptide LINC00954-ORF. The polypeptide had tumor-suppressor features in A549 cells by repressing cell growth, motility and invasion. Moreover, the polypeptide enhanced PEM sensitivity and suppressed growth in A549/PEM cells. The protein interactors of this polypeptide had close correlations with RNA processing, amide metabolic process, translation, RNA binding, RNA transport, and DNA replication. As a conclusion, the LINC00954-ORF polypeptide embedded in lncRNA LINC00954 possesses tumor-suppressor features in A549 and PEM-resistant A549 cells and sensitizes PEM-resistant A549 cells to PEM, providing evidence that the LINC00954-ORF polypeptide is a potential anti-cancer agent in LUAD.

Microproteins transitioning into a new Phase: Defining the undefined

Recent advancements in omics technologies have unveiled a hitherto unknown group of short polypeptides called microproteins (miPs). Despite their size, accumulating evidence has demonstrated that miPs exert varied and potent biological functions. They act in paracrine, juxtracrine, and endocrine fashion, maintaining cellular physiology and driving diseases. The present study focuses on biochemical and biophysical analysis and characterization of twenty-four human miPs using distinct computational methods, including RIDAO, AlphaFold2, D2P2, FuzDrop, STRING, and Emboss Pep wheel. miPs often lack well-defined tertiary structures and may harbor intrinsically disordered regions (IDRs) that play pivotal roles in cellular functions. Our analyses define the physicochemical properties of an essential subset of miPs, elucidating their structural characteristics and demonstrating their propensity for driving or participating in liquid-liquid phase separation (LLPS) and intracellular condensate formation. Notably, miPs such as NoBody and pTUNAR revealed a high propensity for LLPS, implicating their potential involvement in forming membrane-less organelles (MLOs) during intracellular LLPS and condensate formation. The results of our study indicate that miPs have functionally profound implications in cellular compartmentalization and signaling processes essential for regulating normal cellular functions. Taken together, our methodological approach explains and highlights the biological importance of these miPs, providing a deeper understanding of the unusual structural landscape and functionality of these newly defined small proteins. Understanding their functions and biological behavior will aid in developing targeted therapies for diseases that involve miPs.

Subcellular localization and relevant mechanisms of human cancer-related micropeptides

Rapid advances in high-quality sequencing and bioinformatics have invalidated the argument that noncoding RNAs (ncRNAs) are junk transcripts that do not encode proteins. Increasing evidence suggests that small open reading frames (sORFs) in ncRNAs can encode micropeptides and polypeptides within 100 amino acids in length. Several micropeptides have been characterized and proven to have various functions in human physiology and pathology, particularly in cancer. The present review mainly highlights the latest studies on ncRNA-encoded micropeptides in different cancers and categorizes them based on their subcellular localization, thereby providing a theoretical basis for micropeptide applications in the early diagnosis and prognosis of cancer and as therapeutic targets. However, considering the inherent characteristics of micropeptides and the limitations of the assay technology methods, more detailed information is warranted.

Multi-Omics Mining of lncRNAs with Biological and Clinical Relevance in Cancer

In this review, we provide a general overview of the current panorama of mining strategies for multi-omics data to investigate lncRNAs with an actual or potential role as biological markers in cancer. Several multi-omics studies focusing on lncRNAs have been performed in the past with varying scopes. Nevertheless, many questions remain regarding the pragmatic application of different molecular technologies and bioinformatics algorithms for mining multi-omics data. Here, we attempt to address some of the less discussed aspects of the practical applications using different study designs for incorporating bioinformatics and statistical analyses of multi-omics data. Finally, we discuss the potential improvements and new paradigms aimed at unraveling the role and utility of lncRNAs in cancer and their potential use as molecular markers for cancer diagnosis and outcome prediction.

LncRNA-encoded peptides: unveiling their significance in cardiovascular physiology and pathology-current research insights

Long non-coding RNAs (lncRNAs), which are RNA transcripts exceeding 200 nucleotides were believed to lack any protein-coding capacity. But advancements in -omics technology have revealed that some lncRNAs have small open reading frames (sORFs) that can be translated by ribosomes to encode peptides, some of which have important biological functions. These encoded peptides subserve important biological functions by interacting with their targets to modulate transcriptional or signalling axes, thereby enhancing or suppressing cardiovascular disease (CVD) occurrence and progression. In this review, we summarize what is known about the research strategy of lncRNA-encoded peptides, mainly comprising predictive websites/tools and experimental methods that have been widely used for prediction, identification, and validation. More importantly, we have compiled a list of lncRNA- encoded peptides, with a focus on those that play significant roles in cardiovascular physiology and pathology, including ENSRNOT (RNO)-sORF6/RNO-sORF7/RNO-sORF8, dwarf open reading frame (DOWRF), myoregulin (NLN), etc. Additionally, we have outlined the functions and mechanisms of these peptides in cardiovascular physiology and pathology, such as cardiomyocyte hypertrophy, myocardial contraction, myocardial infarction, and vascular remodelling. Finally, an overview of the existing challenges and potential future developments in the realm of lncRNA-encoded peptides was provided, with consideration given to prospective avenues for further research. Given that many lncRNA-encoded peptides have not been functionally annotated yet, their application in CVD diagnosis and treatment still requires further research.

HMGCS2 serves as a potential biomarker for inhibition of renal clear cell carcinoma growth

3-Hydroxymethylglutaryl-CoA synthase 2 (HMGCS2) is the rate-limiting enzyme for ketone body synthesis, and most current studies focus on mitochondrial maturation and metabolic reprogramming. The role of HMGCS2 was evaluated in a pan-cancer multi-database using R language, and HMGCS2 was lowly expressed or not differentially expressed in all tumor tissues compared with normal tissues. Correlation analysis of clinical case characteristics, genomic heterogeneity, tumor stemness, and overall survival revealed that HMGCS2 is closely related to clear cell renal cell carcinoma (KIRC). Single-cell sequencing data from normal human kidneys revealed that HMGCS2 is specifically expressed in proximal tubular cells of normal adults. In addition, HMGCS2 is associated with tumor immune infiltration and microenvironment, and KIRC patients with low expression of HMGCS2 have worse prognosis. Finally, the results of cell counting kit 8 assays, colony formation assays, flow cytometry, and Western blot analysis suggested that upregulation of HMGCS2 increased the expression of key tumor suppressor proteins, inhibited the proliferation of clear cell renal cell carcinoma cells and promoted cell apoptosis. In conclusion, HMGCS2 is abnormally expressed in pan-cancer, may play an important role in anti-tumor immunity, and is expected to be a potential tumor prognostic marker, especially in clear cell renal cell carcinoma.

The DDUP protein encoded by the DNA damage-induced CTBP1-DT lncRNA confers cisplatin resistance in ovarian cancer

Sustained activation of DNA damage response (DDR) signaling has been demonstrated to play vital role in chemotherapy failure in cancer. However, the mechanism underlying DDR sustaining in cancer cells remains unclear. In the current study, we found that the expression of the DDUP microprotein, encoded by the CTBP1-DT lncRNA, drastically increased in cisplatin-resistant ovarian cancer cells and was inversely correlated to cisplatin-based therapy response. Using a patient-derived human cancer cell model, we observed that DNA damage-induced DDUP foci sustained the RAD18/RAD51C and RAD18/PCNA complexes at the sites of DNA damage, consequently resulting in cisplatin resistance through dual RAD51C-mediated homologous recombination (HR) and proliferating cell nuclear antigen (PCNA)-mediated post-replication repair (PRR) mechanisms. Notably, treatment with an ATR inhibitor disrupted the DDUP/RAD18 interaction and abolished the effect of DDUP on prolonged DNA damage signaling, which resulted in the hypersensitivity of ovarian cancer cells to cisplatin-based therapy in vivo. Altogether, our study provides insights into DDUP-mediated aberrant DDR signaling in cisplatin resistance and describes a potential novel therapeutic approach for the management of platinum-resistant ovarian cancer.

Clinical prospects and research strategies of long non-coding RNA encoding micropeptides

Long non-coding RNAs (lncRNAs) which are usually thought to have no protein coding ability, are widely involved in cell proliferation, signal transduction and other biological activities. However, recent studies have suggested that short open reading frames (sORFs) of some lncRNAs can encode small functional peptides (micropeptides). These micropeptides appear to play important roles in calcium homeostasis, embryonic development and tumorigenesis, suggesting their potential as therapeutic targets and diagnostic biomarkers. Currently, bioinformatic tools as well as experimental methods such as ribosome mapping and in vitro translation are applied to predict the coding potential of lncRNAs. Furthermore, mass spectrometry, specific antibodies and epitope tags are used for validating the expression of micropeptides. Here, we review the physiological and pathological functions of recently identified micropeptides as well as research strategies for predicting the coding potential of lncRNAs to facilitate the further research of lncRNA encoded micropeptides.

Identification of novel and potent dual-targeting HDAC1/SPOP inhibitors using structure-based virtual screening, molecular dynamics simulation and evaluation of in vitro and in vivo antitumor activity

Cancer is one of the important factors threatening human health. Hence, it is essential to create novel potent drugs to treat it. Due to the strong correlation among histone deacetylase1 (HDAC1), speckle-type POZ protein (SPOP) and cancers, dual inhibition of HDAC1 and SPOP may be a promising strategy for cancer treatment. In this study, we successfully identified four potential dual-targeting HDAC1/SPOP candidate compounds with structure-based virtual screening. In vitro inhibition experiments confirmed that the four compounds had dual inhibitory effects on HDAC1 and SPOP. Among them, compound HS-2 had a stronger inhibitory effect on HDAC1 and SPOP than the positive controls. Further molecular dynamics simulations indicated that HS-2 could stably bind to HDAC1 and SPOP. In addition, MTT assay indicated that HS-2 inhibited the growth of tumor cells in the micromolar range. In vivo evaluation showed that HS-2 could obviously inhibit the growth of tumor in nude mice without obvious toxicity. These findings suggest that HS-2 is a novel and potent dual-targeting HDAC1/SPOP inhibitor for cancer treatment.

Microproteins: Overlooked regulators of physiology and disease

Ongoing efforts to generate a complete and accurate annotation of the genome have revealed a significant blind spot for small proteins (<100 amino acids) originating from short open reading frames (sORFs). The recent discovery of numerous sORF-encoded proteins, termed microproteins, that play diverse roles in critical cellular processes has ignited the field of microprotein biology. Large-scale efforts are currently underway to identify sORF-encoded microproteins in diverse cell-types and tissues and specialized methods and tools have been developed to aid in their discovery, validation, and functional characterization. Microproteins that have been identified thus far play important roles in fundamental processes including ion transport, oxidative phosphorylation, and stress signaling. In this review, we discuss the optimized tools available for microprotein discovery and validation, summarize the biological functions of numerous microproteins, outline the promise for developing microproteins as therapeutic targets, and look forward to the future of the field of microprotein biology.

LncRNA AC006064.4-201 serves as a novel molecular marker in alleviating cartilage senescence and protecting against osteoarthritis by destabilizing CDKN1B mRNA via interacting with PTBP1

BACKGROUND

Osteoarthritis (OA) is the most prevalent age-related disease in the world. Chondrocytes undergo an age-dependent decline in their proliferation and synthetic capacity, which is the main cause of OA development. However, the intrinsic mechanism of chondrocyte senescence is still unclear. This study aimed to investigate the role of a novel long non-coding RNA (lncRNA), AC006064.4-201 in the regulation of chondrocyte senescence and OA progression and to elucidate the underlying molecular mechanisms.

METHODS

The function of AC006064.4-201 in chondrocytes was assessed using western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), immunofluorescence (IF) and β-galactosidase staining. The interaction between AC006064.4-201 and polypyrimidine tract-binding protein 1 (PTBP1), as well as cyclin-dependent kinase inhibitor 1B (CDKN1B), was evaluated using RPD-MS, fluorescence in situ hybridization (FISH), RNA immunoprecipitation (RIP) and RNA pull-down assays. Mice models were used to investigate the role of AC006064.4-201 in post-traumatic and age-related OA in vivo.

RESULTS

Our research revealed that AC006064.4-201 was downregulated in senescent and degenerated human cartilage, which could alleviate senescence and regulate metabolism in chondrocytes. Mechanically, AC006064.4-201 directly interacts with PTBP1 and blocks the binding between PTBP1 and CDKN1B mRNA, thereby destabilizing CDKN1B mRNA and decreasing the translation of CDKN1B. The in vivo experiments were consistent with the results of the in vitro experiments.

CONCLUSIONS

The AC006064.4-201/PTBP1/CDKN1B axis plays an important role in OA development and provides new molecular markers for the early diagnosis and treatment of OA in the future. Schematic diagram of AC006064.4-201 mechanism. A schematic diagram of the mechanism underlying the effect of AC006064.4-201.