Shuyang Wang

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy worldwide. Despite significant advancements in CRC treatment, metastasis remains the primary determinant of CRC-related mortality. Mammalian unc-51 like autophagy activating kinase 1 and 2 (ULK1 and ULK2), which are serine/threonine protein kinases, serve as crucial regulators of autophagy initiation. While the role of ULK1 in tumor biology has been extensively studied, the functional significance of ULK2 in CRC progression remains unexplored. This study investigated ULK2 expression in CRC patient tissues by immunohistochemistry (IHC) and explored its functional and regulatory roles in transfected DLD-1 and SW480 CRC cell lines. ULK2 expression was elevated at the invasive front of CRC, and this elevation showed a positive association with tumor invasion. ULK2 overexpression was associated with EMT-like phenotypic alterations, including loss of membranous E-cadherin and β-catenin nuclear accumulation, which collectively promoted CRC invasion. Furthermore, ULK2 was found to upregulate MCT4 expression on the plasma membrane, resulting in increased extracellular lactate levels and enhanced invasive capacity in vitro. These findings identify ULK2 as a contributing factor to CRC invasion and highlight its therapeutic potential for suppressing tumor aggressiveness.

Objective To investigate the role and molecular mechanism of exosomal miR-224-5p in colorectal cancer (CRC). Methods The miR-224-5p expression in CRC patient tissues and cell -derived exosomes was measured by laser capture microdissection and qRT-PCR, respectively. Dual-luciferase reporter gene assay was used to determine the target gene of miR-224-5p. The protein expressions of p53 and unc-51 like kinase 2 (ULK2) in CRC cells were detected by western blot. Flow cytometry was used to detect cell cycle and apoptosis. Cell proliferation was measured by CCK8 and EdU assay. Results The miR-224-5p expression was upregulated in CRC tissues and increased progressively with the rise of CRC stage. CRC cells secreted extracellular miR-224-5p mainly in an exosome-dependent manner, and then miR-224-5p could be transferred to surrounding tumor cells to regulate cell proliferation in the form of autocrine or paracrine. Moreover, ULK2 was characterized as a direct target of miR-224-5p and was downregulated in CRC tissues. Interestingly, ULK2 inhibited CRC cell proliferation in a p53 -dependent manner. Furthermore, exosome-derived miR-224-5p partially reversed the proliferation regulation of ULK2 on CRC cells. Conclusion Our findings demonstrate that exosome-transmitted miR-224-5p promotes p53 -dependent cell proliferation by targeting ULK2 in CRC, which may offer promising targets for CRC prevention and therapy.

Background: Salmonella as an important food-borne zoonotic bacterial pathogen, infection in ducks is a recessive infection, however, it can also cause high mortality and threat to food safety. Preventing and controlling the infection and transmission of Salmonella in ducks critically require rapid and sensitive detection method. Full-length Salmonella-specific protein PagN was induced and expressed in E.coil BL21 and was purified as an antigen to establish an indirect enzyme-linked immunosorbent assays (iELSA) detection kit. Results: The recombinant PagN protein has a molecular weight of 43 kDa containing a His-tag, was recognized by an anti-Salmonella positive serum by Western blot assay. The optimal concentration of PagN as a coating antigen in the iELISA was 1 μg/mL, and the optimal dilution of enzyme-labeled secondary antibody was 1:4000 (0.025 μg/mL). The cutoff OD₄₅₀ value was established at 0.268. The iELISA kit showed high selectivity since no cross-reaction with E. coli, Staphylococcus aureus and Streptococcus was observed. iELISA method and Dot-blot test were performed on 100 clinical sera samples collected from duck farms, and the actual coincidence rate was 89% (89/100). 613 duck serum samples from 3 different farms were tested using established method and commercial ELISA kit. The concordance between the two methods was 94.1%. Conclusion: Anti-PagN based iELISA can serve as a useful tool for diagnosis of Salmonella infection.

Exosomal contents have been recognized as candidate biomarkers for cancer screening and prognosis. The current study aimed to evaluate the potential of the expression levels of exosomal enabled homolog (ENAH), septin 9 (SEPT9), epidermal growth factor (EGF), matrix metalloproteinase‑9 (MMP‑9) and C‑X‑C motif chemokine ligand 8 (CXCL8) in the blood for the early screening of breast cancer. Therefore, exosomes were extracted and purified from the peripheral blood of 47 patients with breast cancer, 63 disease controls (DCs) and 33 healthy controls (HCs). Subsequently, the exosomal mRNA expression levels of ENAH, SEPT9, EGF, MMP‑9 and CXCL8 were detected by reverse transcription‑quantitative polymerase chain reaction. The results showed that the exosomal levels of ENAH and EGF were significantly higher in patients with breast cancer compared with DCs and HCs (both P<0.001). In addition, receiver operating characteristic curves revealed that exosomal ENAH was able to discriminate patients with breast cancer from DCs [area under the curve (AUC), 0.841] and HCs (AUC, 0.859). However, exosomal EGF was only able to discriminate patients with breast cancer from HCs (AUC, 0.776). Furthermore, the levels of exosomal SEPT9 were lower in patients with breast cancer compared with DCs and HCs (P=0.021), and exosomal SEPT9 expression levels exhibited good potential in the discrimination of patients with breast cancer from DCs (AUC, 0.717) and HCs (AUC, 0.830). However, no significant difference was detected in exosomal levels of MMP‑9 and CXCL8 among the three groups, and these RNAs showed no discriminative ability. In addition, in patients with breast cancer, the exosomal levels of ENAH were associated with molecular subtypes (P=0.010), while those of MMP‑9 were associated with a Ki‑67 index of ≥30% (P=0.011). In conclusion, the exosomal levels of ENAH, SEPT9 and EGF in blood samples were able to identify patients with breast cancer, thus providing a novel approach for the early screening of breast cancer.

Our study aims to investigate the impact of miR-224 on cell migration and invasion in colorectal cancer (CRC) as well as its molecular mechanisms. The results showed that miR-224 was significantly upregulated in CRC compared to normal tissues via the TCGA database. Overexpression of miR-224 promoted CRC cell migration and invasion, while inhibition of miR-224 demonstrated the opposite result via transwell assays. In addition, we found that BTRC was a target gene of miR-224 through the miRecords database and dual-luciferase assay, while western blot together with RT-qPCR showed that inhibition of miR-224 led to elevated BTRC expression in protein level but not in mRNA level, and also decreased the expression of β-catenin. In reference to the Human Protein Atlas, BTRC protein expression was higher in normal tissues than in CRC tissues. In conclusion, miR-224 regulates its target BTRC protein expression and its related Wnt/β-catenin pathway. Its impact on cell migration and invasion in CRC cells suggested that miR-224 could be a prospective therapeutic target for early-stage non-metastatic CRC.

MiR-650 represses high-risk non-metastatic colorectal cancer progression via inhibition of AKT2/GSK3β/E-cadherin pathway MiR-650 represses high-risk non-metastatic colorectal cancer progression via inhibition of AKT2/GSK3β/E-cadherin pathway

Due to emergence of resistant tumor populations, prognosis for metastatic colorectal cancer (CRC) patients remains poor and five-year survival rate is still very low. To guide clinicians in selecting treatment option for CRC patients, reliable markers predictive of poor clinical outcome are desirable. This study analyzed the correlation of NF-E2-related factor 2 (Nrf2), NAD(P)H quinine oxidoreductase 1 (NQO1), multidrug resistant protein 1 (MRP1), cmyc and p53 in CRC and their relationships to Duke's stage and clinical prognosis. 76 specimens of CRC tissues were immunohistochemically investigated using Nrf2, NQO1, MRP1, cmyc and p53 antibodies. IHC stain showed that Nrf2, NQO1, MRP1, cmyc and p53 were highly expressed in CRC tissues compared with adjacent non-tumor tissues. Significant positive correlations were found between the expression of Nrf2 and that of NQO1, MRP1, cmyc and p53. Moreover, there was significant correlation between the high level of Nrf2, NQO1, MRP1, p53 expression and Duke's stage, as well as poor clinical prognosis. We confirmed that Nrf2, NQO1, MRP1, and p53 expression exhibits considerable heterogeneity according to CRC clinical stage and prognosis. Nrf2 is the most promising biomarker in identifying a poor prognostic group of CRC.