Human β-defensin-1 affects the mammalian target of rapamycin pathway and autophagy in colon cancer cells through long non-coding RNA TCONS_00014506

Incorporation of human β-defensin-1 into immunoliposomes to facilitate targeted autophagy therapy of colon carcinoma

Based on the discovery that human β-defensin-1 (hBD-1) triggers autophagy in colon cancer cells and inhibits proliferation, we proposed the consideration of its druggability. As a protein, its stability, targetability and bioavailability must be improved. Compared with the traditional medicinal chemistry technology, nanotechnology is more economical for increasing the druggability of hBD-1 and can be readily scaled up. Here, we propose an immunoliposome system containing hBD-1 to improve its stability and bioavailability. To enhance its targetability, anti-epidermal growth factor receptor (EGFR) antibodies were conjugated to the liposomal bilayer to produce immunoliposomes that can target EGFR, which is highly expressed in colon cancer cells. Although more studies are needed to support clinical trials and large-scale manufacturing, these immunoliposomes have great potential as therapeutics. Thus, immunoliposomes are suitable nanovesicles to improve the druggability of hBD-1; however, additional basic and translational research of these systems is warranted.

HAS-CIRCpedia-5280 sponges miR-4712-5p inhibited colon cancer autophagyinduced by human beta-defensin-1

BACKGROUND

Among all malignancies, colorectal cancer ranks third in incidence rate and second in mortality rate. Human beta-defensin-1 (hBD-1) has broad-spectrum antimicrobial properties, and it plays an important role in the tumor microenvironment. Circular ribonucleic acids (circRNAs) regulate the proliferation and progression of colorectal cancer cells via cancer-related signaling pathways.

METHODS

Cell proliferation was assessed using the Cell Counting Kit-8 assay to determine the optimal hBD-1 concentration. Intracellular autophagic vesicles were visualized via monodansylcadaverine staining. In addition, the levels of AKT and mammalian target of rapamycin (mTOR)-associated signaling proteins were analyzed via Western blot analysis. CircRNA microarrays and quantitative real-time polymerase chain reaction were used to identify differentially expressed circRNAs in colon cancer cell lines. The functional role of HAS-CIRCpedia-5280 in vitro was demonstrated by overexpressing HAS-CIRCpedia-5280 and inhibiting miR-4712-5p. HAS-CIRCpedia-5280 could be a sponge of miR-4712-5p, mimicking the effect induced by HAS-CIRCpedia-5280 overexpression in colon cancer cells.

RESULTS

hBD-1 inhibited the proliferation of colon cancer cells and increased the number of intracellular autophagic vesicles. In addition, hBD-1 inhibited the AKT/mTOR signaling pathway, thereby enhancing cellular autophagy. Further, the interaction of HAS-CIRCpedia-5280 and miR-4712-5p was investigated. hBD-1 upregulated the expression level of HAS-CIRCpedia-5280 and downregulated the expression level of miR-4712-5p in colon cancer cells. Subsequently, the overexpression of HAS-CIRCpedia-5280 or the inhibition of miR-4712-5p activated the AKT/mTOR signaling pathway, leading to cellular autophagy inhibition. Conversely, the mimicry of miR-4712-p counteracted the effect of HAS-CIRCpedia 5280 overexpression in colon cancer cells by inhibiting the activation of the AKT/mTOR signaling pathway and, thereby, enhancing cellular autophagy.

CONCLUSION

hBD-1 can have an inhibitory effect against cell proliferation in colon cancer SW-620/HCT-116 cells via the HAS-CIRCpedia-5280/miR-4712-5p-mediated activation of autophagy.

Molecular mechanisms underlying roles of long non-coding RNA small nucleolar RNA host gene 16 in digestive system cancers

This editorial reviews the molecular mechanisms underlying the roles of the long non-coding RNA (lncRNA) small nucleolar RNA host gene 16 (SNHG16) in digestive system cancers based on two recent studies on lncRNAs in digestive system tumors. The first study, by Zhao et al, explored how hBD-1 affects colon cancer, via the lncRNA TCONS_00014506, by inhibiting mTOR and promoting autophagy. The second one, by Li et al, identified the lncRNA prion protein testis specific (PRNT) as a factor in oxaliplatin resistance by sponging ZNF184 to regulate HIPK2 and influence colorectal cancer progression and chemoresistance, suggesting PRNT as a potential therapeutic target for colorectal cancer. Both of these two articles discuss the mechanisms by which lncRNAs contribute to the development and progression of digestive system cancers. As a recent research hotspot, SNHG16 is a typical lncRNA that has been extensively studied for its association with digestive system cancers. The prevailing hypothesis is that SNHG16 participates in the development and progression of digestive system tumors by acting as a competing endogenous RNA, interacting with other proteins, regulating various genes, and affecting downstream target molecules. This review systematically examines the recently reported biological functions, related molecular mechanisms, and potential clinical significance of SNHG16 in various digestive system cancers, and explores the relationship between SNHG16 and digestive system cancers. The findings suggest that SNHG16 may serve as a potential biomarker and therapeutic target for human digestive system cancers.

Navigating the labyrinth of long non-coding RNAs in colorectal cancer: From chemoresistance to autophagy

Long non-coding RNAs (lncRNAs), with transcript lengths exceeding 200 nucleotides and little or no protein-coding capacity, have been found to impact colorectal cancer (CRC) through various biological processes. LncRNA expression can regulate autophagy, which plays dual roles in the initiation and progression of cancers, including CRC. Abnormal expression of lncRNAs is associated with the emergence of chemoresistance. Moreover, it has been confirmed that targeting autophagy through lncRNA regulation could be a viable approach for combating chemoresistance. Two recent studies titled "Human β-defensin-1 affects the mammalian target of rapamycin pathway and autophagy in colon cancer cells through long non-coding RNA TCONS_00014506" and "Upregulated lncRNA PRNT promotes progression and oxaliplatin resistance of colorectal cancer cells by regulating HIPK2 transcription" revealed novel insights into lncRNAs associated with autophagy and oxaliplatin resistance in CRC, respectively. In this editorial, we particularly focus on the regulatory role of lncRNAs in CRC-related autophagy and chemoresistance since the regulation of chemotherapeutic sensitivity by intervening with the lncRNAs involved in the autophagy process has become a promising new approach for cancer treatment.

Human β-defensin-1 activates autophagy in human colon cancer cells via regulation of long non-coding RNA TCONS_00014506

Macroautophagy (hereafter referred to as autophagy) is a prosurvival mechanism for the clearance of damaged cellular components, specifically related to exposure to various stressors such as starvation, excessive ethanol intake, and chemotherapy. This editorial reviews and comments on an article by Zhao et al, to be published in World J Gastrointestinal Oncology in 2024. Based on various molecular biology methodologies, they found that human β-defensin-1 reduced the proliferation of colon cancer cells, which was associated with the inhibition of the mammalian target of rapamycin, resulting in autophagy activation. The activation of autophagy is evidenced by increased levels of Beclin1 and LC3II/I proteins and mediated by the upregulation of long non-coding RNA TCONS_00014506. Our study discusses the impact of autophagy activation and mechanisms of autophagy, including autophagic flux, on cancer cells. Additionally, we emphasize the importance of describing the detailed methods for isolating long noncoding RNAs TCONS_00014506. Our review will benefit the scientific community and improve the overall clarity of the paper.