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Colitis-associated colorectal cancer (CAC) develops from chronic intestinal inflammation. Dihydroartemisinin (DHA) is an antimalarial drug exhibiting anti-inflammatory and anti-tumor effects. Nonetheless, the therapeutic effects of DHA on CAC remain unestablished. Methods: Mice were challenged with azoxymethane (AOM) and dextran sulfate sodium (DSS) to establish CAC models. DHA was administered via oral gavage in different stages of CAC models. Colon and tumor tissues were obtained from the AOM/DSS models to investigate inflammatory responses and tumor development. Inflammatory cytokines in the murine models were detected through qRT-PCR and ELISA. Toll-like receptor 4 (TLR4) signaling-related proteins were detected by western blot. Macrophage infiltration was measured using immunostaining analysis, and apoptosis in the colon cancer cells was detected by flow cytometry and western blot. Results: DHA inhibited inflammatory responses in the early stage of the AOM/DSS model and subsequent tumor formation. In the early stage, DHA reversed macrophage infiltration in colon mucosa and decreased the expression of pro-inflammatory cytokines. DHA inhibited the activation of macrophage by suppressing the TLR4 signal pathway. In the late stage of CAC, DHA inhibited tumor growth by enhancing cell cycle arrest and apoptosis in tumor cells. Administration of DHA during the whole period of the AOM/DSS model generated an addictive effect based on the inhibition of inflammation and tumor growth, thereby improving the therapeutic effect of DHA on CAC. Conclusion: Our study indicated that DHA could be a potent agent in managing the initiation and development of CAC without obvious side effects, warranting further clinical translation of DHA for CAC treatment.

134 Background: Chemoradiation is the standard neoadjuvant treatment for locally advanced rectal cancer. Microsatellite stable (MSS)/ mismatch repair proficient (pMMR) rectal cancer rarely responds to immune checkpoint inhibitor monotherapy, but combination with chemoradiation may improve sensitivity of MSS/pMMR tumors by inducing immune-stimulatory effects. Therefore, we aimed to investigate the efficacy and safety of patients treated with neoadjuvant preoperative short-course radiation followed by envafolimab plus CAPEOX for MSS/pMMR locally advanced rectal cancer. Methods: This is an open-label, single-center, phase ¢ò study. Patients (pts) with locally advanced rectal adenocarcinoma with MSS/pMMR were eligible. MMR protein expression was tested by immunohistochemistry (IHC) £¬and MSI status was confirmed by NGS (next generation sequencing). All pts included in this study underwent neoadjuvant short-course radiation (total dose of 5¡Á5Gy) in the first week after enrollment, then followed by 6 cycles of envafolimab (anti-PD-L1 inhibitor,150mg, d1, subcutaneous injection, QW) plus 2 cycles of CAPEOX in the next six weeks, and subsequently underwent total mesorectal excision (TME) in the ninth week. The primary endpoint is pathological complete response rate. Secondary endpoints include tumor regression grade (TRG), 3 year disease free survival, overall survival, toxicity, and quality of life (QoL). Results: This study intends to recruit 32 pts, and a total of 21 pts were enrolled from January 2022 to September 2022. Overall median age was 67 (42-79) years. 12 pts completed study designed treatment protocol (envafolimab plus CAPOX) followed with TME procedures, and 9 pts are still undergoing neoadjuvant treatment. All 12 pts achieved major partial response (MPR) evaluated by diffusion-weighted magnetic resonance imaging (DW-MRI), and 8 pts (8/12,76.6%) achieved pCR. During neoadjuvant treatment period, 20 pts (20/21, 95.2%) presented with treatment-related AEs (TRAEs) of any grade, 18 pts (18/21, 85.7%) had grade 1-2 and one each pts had grade 3 and 4 thrombocytopenia (2/21, 9.5%). The most common TRAEs were sensation of rectal tenesmus. Conclusions: Neoadjuvant preoperative short-course radiation followed by envafolimab plus CAPEOX in MSS/pMMR locally advanced rectal cancer achieved a promising pathologic response. Meanwhile, this combination neoadjuvant therapy is safe and worthy of application to clinical practice. (Funded by Sir Run Run Shaw Hospital Zhejiang University School of Medicine.) Clinical trial information: NCT05216653 .

Rectal leiomyosarcoma is a rare neoplasm, and no standard therapeutic strategy has been established, other than surgical resection. The prognosis of advanced leiomyosarcoma in the rectum is poor. We describe a case of a 47-year-old man with a locally advanced rectal leiomyosarcoma who presented with anal bleeding and lower abdominal pain. After discussions by a multidisciplinary team (MDT), the patient received preoperative pelvic short-course radiotherapy followed by laparoscopic-assisted abdominoperineal resection. Adjuvant chemotherapy with doxorubicin and ifosfamide was administered postoperatively. Local recurrence was detected 13 months after the resection. The patient received chemotherapy with gemcitabine and docetaxel followed by radioactive particle implantation. Thereafter, apatinib was administered to gain systemic control. The patient died 24 months after the diagnosis. This case report draws attention to treatment with multidisciplinary therapy, as discussed by MDT, for rare locally advanced rectal leiomyosarcoma.

Clear cell renal cell carcinoma (ccRCC) is a major histological subtype of renal cell carcinoma and can be clinically divided into four stages according to the TNM criteria. Identifying clinical stage-related genes is beneficial for improving the early diagnosis and prognosis of ccRCC. By using bioinformatics analysis, we aim to identify clinical stage-relevant genes that are significantly associated with the development of ccRCC. First, we analyzed the gene expression microarray data sets: GSE53757 and GSE73731. We divided these data into five groups by staging information—normal tissue and ccRCC stages I, II, III, and IV—and eventually identified 500 differentially expressed genes (DEGs). To obtain precise stage-relevant genes, we subsequently applied weighted gene coexpression network analysis (WGCNA) to the GSE73731 dataset and KIRC data from The Cancer Genome Atlas (TCGA). Two modules from each dataset were identified to be related to the tumor TNM stage. Several genes with high inner connection inside the modules were considered hub genes. The intersection results between hub genes of key modules and 500 DEGs revealed UBE2C, BUB1B, RRM2, and TPX2 as highly associated with the stage of ccRCC. In addition, the candidate genes were validated at both the RNA expression level and the protein level. Survival analysis also showed that 4 genes were significantly correlated with overall survival. In conclusion, our study affords a deeper understanding of the molecular mechanisms associated with the development of ccRCC and provides potential biomarkers for early diagnosis and individualized treatment for patients at different stages of ccRCC.

Background Carcinoembryonic antigen (CEA) is a cancer biomarker used in colorectal cancer (CRC) for tumor screening and outcome prediction. However it is still lack of sensitivity and specificity in general population. The present study aimed to investigate the clinical significance of CEA in patients with normal preoperative CEA levels. Methods Ninety-four patients were included who received surgery and developed an elevated CEA level postoperatively. They were divided into group A1 and A2 according to the peak CEA level (whether more than 10 ng/mL); group B1 and B2 according to CEA variation (whether reached a normal level at least once). The association between postoperative CEA and overall survival (OS), and disease-free survival (DFS) were analyzed using Kaplan-Meier method and Cox’s proportional hazards regression model. Results The median follow-up time was 38 months. Patients in Group A2 and Group B2 had greater opportunities for recurrence and metastasis (P

In our previous study, it was reported that 2[[3-(2,3-dichlorophenoxy)propyl]amino]ethanol (2,3-DCPE) induces apoptosis and cell cycle arrest. The current study aimed to investigate the molecular mechanism involved in 2,3-DCPE-induced S phase arrest. The results demonstrated that 2,3-DCPE upregulated phosphorylated (p-)H2A histone family member X, a biomarker of DNA damage, in the DLD-1 colon cancer cell line. Western blotting revealed that 2,3-DCPE increased the checkpoint kinase (Chk)1 (Ser317 and Ser345) level and decreased the expression of M-phase inducer phosphatase 1 (Cdc25A) in a time-dependent manner. Subsequently, the results demonstrated that the ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia and Rad3-related (ATR) inhibitors wortmannin and caffeine had no effect on the cell cycle; however, the inhibitors partially abrogated 2,3-DCPE-induced S phase arrest. Flow cytometry assays revealed that caffeine (2 mM) reduced the proportion of S phase cells from 83 to 39.6% and that wortmannin (500 nM) reduced the proportion of S phase cells from 83 to 48.2%. Furthermore, wortmannin and caffeine inhibited the 2,3-DCPE-mediated phosphorylation of Chk1 and the degradation of Cdc25A. However, these ATM/ATR inhibitors had limited effect on 2,3-DCPE-induced apoptosis. Taken together, the data of the current study indicated that 2,3-DCPE caused DNA damage in colon cancer cells and that 2,3-DCPE-induced S phase arrest was associated with the activation of the ATM/ATR-Chk1-Cdc25A pathway.

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An enhanced anti-apoptotic capacity of tumor cells plays an important role in the process of breakpoint cluster region/Abelson tyrosine kinase gene (BCR/ABL)-independent imatinib resistance. We have previously demonstrated that brain expressed X-linked 1 (BEX1) was silenced in secondary imatinib-resistant K562 cells and that re-expression of BEX1 can restore imatinib sensitivity resulting in the induction of apoptosis. However, the mechanism by which BEX1 executes its pro-apoptotic function remains unknown. We identified B-cell lymphoma 2 (BCL-2) as a BEX1-interacting protein using a yeast two-hybrid screen. The interaction between BEX1 and BCL-2 was subsequently confirmed by co-immunoprecipitation assays. Like BCL-2, BEX1 was localized to the mitochondria. The region between 33K and 64Q on BEX1 is important for its localization to the mitochondria and its ability to interact with BCL-2. Additionally, we found that this region is essential for BEX1-regulated imatinib-induced apoptosis. Furthermore, we demonstrated that the interaction between BCL-2 and BEX1 promotes imatinib-induced apoptosis by suppressing the formation of anti-apoptotic BCL-2/BCL-2-associated X protein (BAX) heterodimers. Our results revealed an interaction between BEX1 and BCL-2 and a novel mechanism of imatinib resistance mediated by the BEX1/BCL-2 pathway.

To construct a recombinant lentiviral vector that stably express hepatocyte nuclear factor 6 (HNF6) in colorectal cancer cell line and examine its effects on the invasive ability of SW620 cells.The lentiviral vector pLeno-DCE-HA-HNF6 was constructed and transfected into 293T cells. The supernatant containing the lentivirus particles was harvested to determine the virus titer. A stable cell line was established by infecting SW620 cells with the lentivirus particles, and the transfection efficiency was examined by fluorescence microscopy and flow cytometry. The invasion ability of the transfected SW620-HNF6 cells was assessed by wound healing and transwell assays.The recombinant lentiviral vector was correctly constructed and verified by sequencing. SW620-HNF6 cell line with stable HNF6 expression was established successfully, and the transfection efficiency reached 82.3%. Western blotting and quantitative PCR demonstrated significantly upregulated HNF6 expression in SW620-HNF6 cells, which showed obviously suppressed invasive ability in wound healing and transwell assays.We have successfully established a colorectal cancer cell line SW620-HNF6 stably expressing HNF6, which shows a lowered migration activity in vitro.