Enhancing the Anti-Tumor Efficacy of NK Cells on Canine Mammary Tumors through Resveratrol Activation.

In order to explore the therapeutic effect of Resveratrol (Res)-activated Natural Killer (NK) cells on canine mammary tumors, this study employed a range of assays, including wound healing, colony formation, Transwell, flow cytometry, and Western blot experiments, to investigate the impact of Res-pretreated NK cells on canine mammary tumor cells in vitro. Additionally, a tumor-bearing mouse model was utilized to further analyze the therapeutic effects of Res-pretreated NK cells in vivo. The results showed that Res enhances the capacity of NK cells to induce apoptosis, pyroptosis, and ferroptosis in canine breast tumor cells, while also augmenting their influence on the migration, invasion, and epithelial-mesenchymal transition of these cells. Furthermore, pretreatment of NK cells with Res significantly amplified their inhibitory effect on breast tumor growth in vivo and promoted tumor tissue apoptosis. Additionally, Res enhanced the recruitment of NK cells to other immune cells in the body. In summary, Res has been shown to enhance the anti-breast-tumor effect of NK cells both in vitro and in vivo, offering a new avenue for optimizing immunotherapy for canine breast tumors.

Establishment and characterization of cisplatin-resistant cell lines from canine mammary gland tumors.

The development of cisplatin resistance is one of the major causes of mammary cancer treatment failure, and is associated with changes in Sox4 gene expression. To investigate the characteristic changes that occur in canine mammary gland tumor (CMGT) cells following the development of acquired cisplatin resistance, along with the relationship between these changes and the Sox4 gene. We constructed cisplatin-resistant cell line, CHMpCIS, from the cell line CHMp, which was isolated from the primary lesion of a malignant CMGT. The biological characteristics of these cells were examined by Western blot analysis, Transwell assays, and mammosphere formation assays. Compared to CHMp cells, CHMpCIS cells exhibited elevated cisplatin resistance, apoptotic escape ability, enhanced epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) features, in addition to over-activation of the Wnt/ß-catenin signaling pathway and increased Sox4 protein. In CMGT cases, CMGT tissues (CMGTT) expressed higher levels of Sox4 protein and mRNA compared to adjacent tissues (CAMGTT). We found that these changes were inhibited by silencing of Sox4 expression in CHMpCIS cells. Furthermore, activation of the Wnt/ß-catenin signaling pathway increased Sox4 expression levels through a positive feedback loop. These results suggested that CHMpCIS cells circumvented the damage caused by cisplatin through altering the expression of the Sox4 gene and activating the Wnt/ß-catenin pathway, thereby changing the cellular biological characteristics.

Aspirin alleviates cisplatin-induced acute kidney injury through the AMPK-PGC-1α signaling pathway.

Cisplatin (CIS) is a widely used clinical chemotherapeutic agent for solid malignancies such as lung, testicular and ovarian cancers, but the development of nephrotoxicity has limited the use of this class of drugs. Some studies have shown that aspirin can reduce cisplatin-induced nephrotoxicity, but the mechanism of protection is not yet clear. By establishing a mouse model of cisplatin-induced acute kidney injury and a mouse model of aspirin combination, we observed a reduction in creatinine, blood urea nitrogen, and tissue damage, thus verifying that aspirin can alleviate cisplatin-induced acute kidney injury in mice. Aspirin was found to have a significant protective effect against cisplatin-induced acute kidney injury, as evidenced by the reduction in levels of ROS, NO, and MDA and the increase in T-AOC, CAT, SOD, and GSH. Furthermore, aspirin was observed to down-regulate the expression of pro-inflammatory factors TNF-α, NF-κB, IL-1ß, and IL-6 mRNA and proteins, increase the expression of BAX and Caspase3 as indicators of apoptosis, decrease the expression of Bcl-2, and improve the reduced expression of mtDNA, ATP content, ATPase activity and mitochondrial respiratory chain complex enzyme-related genes ND1, Atp5b, and SDHD. These findings suggest that the protective effects of aspirin are associated with its anti-inflammatory, antioxidant, anti-apoptotic properties, and its ability to maintain mitochondrial function, as demonstrated by the detection of AMPK-PGC-1α pathway-related genes. The results showed that the reduced expression of p-AMPK and mitochondrial production-related mRNA PGC-1α, NRF1, and TFAM in the kidney tissue of mice in the cisplatin group was alleviated by the effect of aspirin, indicating that aspirin could activate the p-AMPK, regulate mitochondrial production and alleviate cisplatin acute kidney injury through the AMPK-PGC-1α pathway. In summary, certain doses of aspirin protect the body from acute kidney injury by alleviating the cisplatin-induced inflammatory response oxidative stress, mitochondrial dysfunction, and apoptosis. Further studies have shown that the protective effect of aspirin is associated with AMPK-PGC-1α pathway activation.

Establishment and transcriptome characterization of tamoxifen-resistant canine mammary gland tumor cells.

Tamoxifen (TAM) currently is still the drug of choice for endocrine therapy in patients with estrogen receptor positive breast cancer. However, the development of drug resistance not only limits the drug utilization, but also greatly reduces the survival of patients. At the same time, TAM is poorly understood in canine mammary gland tumors. Therefore, it is crucial to find effective methods to reverse drug resistance and prevent the development of drug resistance so as to improve the efficacy of endocrine therapy for breast cancer. Firstly, we successfully established two TAM-resistant canine mammary gland tumor cells lines including TAMp,TAMm by drug concentration gradient plus drug maintenance, and then we confirmed that the resistant cells have stronger proliferation, migration, invasion and cloning ability by CCK8, Wound healing assay, Transwell invasion assay and Clone formation assay. Second, we performed sequencing analysis of TAMm and CHMm and detected a large number of different expression genes, including reported and novel drug-resistant genes, and genes involved in complex biological processes. Finally, we explored the role of the classical Wnt signaling pathway in drug-resistant cells, and immunofluorescence and western blot results showed increased expression of Wnt pathway related genes ß-catenin and P-GSK3ß in drug-resistant cells, indicating abnormal activation of the classical Wnt/ß-catenin pathway This study successfully established two TamR cell lines and assayed its resistance generation in many aspects, which provides a good experimental model and theoretical support for a more comprehensive understanding of the endocrine drug resistance mechanism.

LncRNA-42060 Regulates Tamoxifen Sensitivity and Tumor Development via Regulating the miR-204-5p/SOX4 Axis in Canine Mammary Gland Tumor Cells.

Tamoxifen is the drug of choice for endocrine therapy of breast cancer. Its clinical use is limited by the development of drug resistance. There is increasing evidence that long non-coding RNAs (lncRNAs) are associated with tumor drug resistance. Therefore, we established two TAM-resistant cell lines, CHMpTAM and CHMmTAM. The different expression levels of lncRNA and miRNA in CHMmTAM and CHMm were screened by RNA sequencing, and the lncRNA-miRNA interactions were analyzed. LncRNA ENSCAFG42060 (lnc-42060) was found to be significantly upregulated in drug-resistant cells and tumor tissues. Further functional validation revealed that the knockdown of lnc-42060 inhibited proliferation, migration, clone formation, restoration of TAM sensitivity, and reduction of stem cell formation in drug-resistant cells, whereas overexpression of lnc-4206 showed opposite results. Bioinformatics and dual-luciferase reporter gene assays confirmed that lnc-42060 could act as a sponge for miR-204-5p, further regulating SOX4 expression activity and thus influencing tumor cell progression. In conclusion, we screened lncRNAs and miRNAs associated with TAM resistance in canine mammary gland tumor cells for the first time. lnc-42060 served as a novel marker that may be used as an important biomarker for future diagnosis and treatment.