Shikonin-mediated PD-L1 degradation suppresses immune evasion in pancreatic cancer by inhibiting NF-κB/STAT3 and NF-κB/CSN5 signaling pathways.

BACKGROUND: Pancreatic cancer (PC) is a highly fatal malignancy with few effective therapies currently available. Recent studies have shown that PD-L1 inhibitors could be potential therapeutic targets for the treatment of PC. The present study aims to investigate the effect of Shikonin on immune evasion in PC with the involvement of the PD-L1 degradation. METHODS: Initially, the expression patterns of PD-L1 and NF-κB in PC were predicted in-silico using the GEPIA database, and were subsequently validated using PC tissues. Thereafter, the correlation of NF-κB with STAT3, CSN5 and PD-L1 was examined. PC cells were treated with Shikonin, NF-κB inhibitor, STAT3 activator, and CSN5 overexpression plasmid to investigate effects on PD-L1 glycosylation and immune evasion in PC. Finally, in vivo tumor formation was induced in C57BL/6J mice, in order to verify the in vitro results. RESULTS: PD-L1, NF-κB, NF-κB p65, STAT3, and CSN5 were highly expressed in PC samples, and NF-κB was positively correlated with STAT3/CSN5/PD-L1. Inhibition of NF-κB decreased PD-L1 glycosylation and increased PD-L1 degradation, whereas activated STAT3 and overexpressed CSN5 reversed these trends. Shikonin blocked immune evasion in PC, and lowered the expression of PD-L1, NF-κB, NF-κB p65, STAT3 and CSN5 in vivo and in vitro. CONCLUSION: The findings indicated Shikonin inhibited immune evasion in PC by inhibiting PD-L1 glycosylation and activating the NF-κB/STAT3 and NF-κB/CSN5 signaling pathways. These effects of Shikonin on PC cells may bear important potential therapeutic implications for the treatment of PC.

Overexpression of long non-coding RNA00355 enhances proliferation, chemotaxis, and metastasis in colon cancer via promoting GTF2B-mediated ITGA2.

Long non-coding RNAs (LncRNAs) can regulate physiological and pathological functions, exhibiting a wide range of roles in cell biology. Moreover, many lncRNAs are dysregulated in various cancers, including colon cancer. In this study, we investigated the role of the lncRNA LINC00355 in colon cancer, after first establishing its interaction with GTF2B, and ITGA2 on the LncMap database. The predicted relationships between the lncRNA LINC00355, GTF2B, and ITGA2 were identified using luciferase reporter assay, RIP, and ChIP experiments. Western blot analysis and RT-qPCR were applied to determine expression pattern of lncRNA LINC00355 and ITGA2 in colon cancer cells. Additionally, EdU, TUNEL, Cell-adhesion and Transwell assay was used for the detection of the effects of this axis on proliferation, apoptosis, adhesion, chemotaxis and metastasis. LncRNA LINC00355 targeted IGFBP2 through the recruitment of GTF2B. LncRNA LINC00355 was highly expressed in colon cancer cells, and overexpression of lncRNA LINC00355 increased the expression of IGFBP2 and GTF2B, and thereby promoted the proliferation, chemotaxis, invasion, and migration in colon cancer. In summary, downregulation of lncRNA LINC00355 in colon cancer inhibited tumor growth in colon cancer through effects on the GTF2B/IGFBP2 axis.

Downregulation of long non-coding RNA MAFG-AS1 represses tumorigenesis of colorectal cancer cells through the microRNA-149-3p-dependent inhibition of HOXB8.

BACKGROUND: Colorectal cancer (CRC) is considered as the second common death-induced cancer. More recently, association of long non-coding RNAs (lncRNAs) with CRC has been extensively investigated. Therefore, the present study was performed to determine whether lncRNA MAF BZIP Transcription Factor G Antisense RNA 1 (MAFG-AS1) could regulate biological activities of CRC cells and unravel the underlying mechanisms. METHODS: CRC and corresponding adjacent tissues were collected to determine the expression of lncRNA MAFG-AS1, microRNA-149-3p (miR-149-3p) and homeobox B8 (HOXB8) by RT-qPCR. Dual luciferase reporter gene assay was used to explore the targeting relationship between miR-149-3p and lncRNA MAFG-AS1 and between miR-149-3p and HOXB8, followed by RNA immunoprecipitation for verification. Migration, proliferation, invasion, and apoptosis of HCT116 and LoVo cells were examined when lncRNA MAFG-AS1 was silenced or miR-149-3p was overexpressed. Furthermore, tumorigenicity of HCT116 and LoVo cells was measured in vivo by tumor xenograft in nude mice. RESULTS: LncRNA MAFG-AS1 and HOXB8 were found to be highly expressed in CRC tissues and cells, while miR-149-3p was under-expressed. LncRNA MAFG-AS1 negatively regulated miR-149-3p while miR-149-3p downregulated HOXB8. In addition, lncRNA MAFG-AS1 silencing by shRNA or miR-149-3p upregulation by mimic suppressed the migration, proliferation, invasion and tumorigenesis but promoted the apoptosis of HCT116 and LoVo cells. CONCLUSION: Taken together, lncRNA MAFG-AS1 downregulation inhibits the malignant behaviors of CRC cells by upregulating miR-149-3p and downregulating HOXB8, providing a potential therapeutic target for CRC treatment.

Exogenous hydrogen sulfide protects fatty liver against ischemia-reperfusion injury by regulating endoplasmic reticulum stress-induced autophagy in macrophage through mediating the class A scavenger receptor pathway in rats.

Fatty liver disease is a disease manifested with excessive alcohol intake and obese. Importantly, hydrogen sulfide (H2 S) has been revealed to participate in the progression of fatty liver; however, the underlying mechanism has not been clearly elucidated yet. In this study, we aimed to investigate the effects of exogenous H2 S on fatty liver ischemia-reperfusion injury (IRI) through mediating class A scavenger receptor (SRA) pathway in rats. By determining endoplasmic reticulum stress (ERS)-related factors, autophagy markers and apoptosis-related factors in liver tissue and liver function, levels of oxidative stress, inflammatory factors, and hepatocyte apoptosis, the effects of H2 S on IRI-induced autophagy, oxidative stress, and inflammation were all examined in rat model of fatty liver IRI. Results from obtained data showed that H2 S decreased the expression of SRA, Grp78, PERK, CHOP, and Caspase-3, and increased that of LC3-II/LC3-I, in addition to alleviating the pathological changes of liver and reducing the levels of ALT, AST, LDH TBARS, and MDA. Moreover, H2 S decreased the levels of oxidative stress, the expression of pro-inflammatory factors including tumor necrosis factor α, interleukin 1, and interleukin 6, and the apoptosis of hepatocytes. Our findings suggested exogenous H2 S could reduce ERS by mediating the SRA pathway and protect liver function by inducing autophagy, and protect against IRI by reducing oxidative stress and inflammation.

KYA1797K down-regulates PD-L1 in colon cancer stem cells to block immune evasion by suppressing the ß-catenin/STT3 signaling pathway.

Cancer stem cells (CSCs) are considered to mediate tumorigenesis, recurrence, and metastasis. KYA1797K, a ß-catenin inhibitor, has been identified for its functionality as a tumor suppressor gene in colorectal cancer through inhibition of the Wnt/ß-catenin signaling pathway. However, it remains uncertain whether KYA1797K attenuates immune evasion of colon CSCs. Hence, this study is designed for evaluating the function of KYA1797K in colon CSCs. The expression of ß-catenin and STT3A/B in colon cancer tissues was initially detected by immunohistochemistry, followed by correlation analyses of the survival rate with the expression of ß-catenin and STT3A/B as well as identification of the interaction between ß-catenin and STT3A/B. Besides, ß-catenin in colon CSCs was knocked down or inhibited by KYA1797K to explore its role in immune evasion and the subsequent underlying mechanism associated with STT3A/B expression and PD-L1 glycosylation. Additionally, the in vivo regulatory effects of ß-catenin silencing and KYA1797K were evaluated by assessing tumor formation, detecting CD8 and GZMB expression and CD8+ T cell viability. The results collected displayed that ß-catenin and STT3A/B showed high expression in colon cancer tissues, both of which were correlated with poor survival of colon cancer patients. ß-catenin was found to positively regulate STT3A/B expression. Besides, ß-catenin silencing or KYA1797K treatment down-regulated the expression of STT3A/B, inhibited PD-L1 glycosylation and suppressed immune evasion of colon CSCs both in vivo and in vitro. Altogether, KYA1797K inhibits the ß-catenin/STT3 signaling pathway to reduce the stability of PD-L1, thus further inhibiting immune evasion and inducing apoptosis of colon CSCs, which contributes to the development of immunotherapy for colon cancer.

Regulation of Long Non-Coding RNA-Dreh Involved in Proliferation and Migration of Hepatic Progenitor Cells during Liver Regeneration in Rats.

Liver regeneration plays a significant role in protecting liver function after liver injury or chronic liver disease. Long non-coding RNAs (lncRNAs) are considered to be involved in the proliferation of hepatocytes and liver regeneration. Therefore, this study aimed to explore the effects of LncRNA-Dreh on the regulation of hepatic progenitor cells (HPCs) during liver regeneration in rats. Initially, the rat model of liver injury was established to investigate the effect of LncRNA-Dreh down-regulation on liver tissues of rats with liver injury. Subsequently, HPCs line WB-F344 cells were transfected with interference plasmid of LncRNA-Dreh and the expression of LncRNA-Dreh and Vimentin was detected. The proliferation and migration ability of WB-F344 cells, as well as the content of albumin (ALB) and alpha fetoprotein (AFP) in cell differentiation were then determined. Disorderly arranged structure of liver tissue, a large number of HPCs set portal area as center extended to hepatic lobule and ductular reaction were observed in liver tissues of rats with liver injury. The expression of LncRNA-Dreh decreased while Vimentin increased in liver tissues of rats with liver injury. Moreover, the proliferation and migration ability, expression of Vimentin and AFP in WB-F344 cells were increased after silencing of LncRNA-Dreh and ALB was decreased. Collectively, our findings demonstrate that inhibition of LncRNA-Dreh can enhance the proliferation and migration abilities of HPCs in liver regeneration but cause abnormal differentiation of HPCs.