The effects of chemotherapeutic drugs on PD-L1 gene expression in breast cancer cell lines

Characterization and Evaluation of Nano-niosomes Encapsulating Docetaxel against Human Breast, Pancreatic, and Pulmonary Adenocarcinoma Cancer Cell Lines

Background

Docetaxel (DXL) is an antineoplastic agent for cancer treatment, the therapeutic efficiency of which is limited due to low solubility, hydrophobicity, and tissue specificity.

Objective

In this study, nano-niosomes were introduced for improving therapeutic index of DXL.

Material and Methods

In this experimental study, two nano-niosomes were synthesized using Span 20® and Span 80® and a thin film hydration method with DXL loading (DXL-Span20 and DXL-Span80). Characterization, in-vitro cytotoxicity and bioavailability of the nano-niosomes was also evaluated via in-vivo experiments.

Results

DXL-Span20 and DXL-Span80 have vesicles size in a range of 84-90 nm and negative zeta potentials. DXL entrapment efficiencies were obtained as 69.6 and 74.0% for DXL-Span20 and DXL-Span80, respectively; with an in-vitro sustained release patterns. Cytotoxicity assays were performed against MDA-MB-231, Calu-6, and AsPC-1 cell lines, and the results indicated that DXL loading into nano-niosomes led to decrement in values of half-maximal inhibitory concentration (IC50) at least 2.5 times and at most 6.5 times, compared to free DXL. Moreover, the rat blood bioavailability of DXL after intraperitoneal administration and the pharmacokinetic parameters indicated higher DXL plasma level and the higher effectiveness of DXL-Span80 compared to DXL-Span20.

Conclusion

Carrying DXL by the nano-niosomes led to enhanced cytotoxicity (and lower IC50 values) and higher efficacy with enhanced pharmacokinetic parameters.

Construction of a prognostic model for lung adenocarcinoma based on m6A/m5C/m1A genes

BACKGROUND

Developing a prognostic model for lung adenocarcinoma (LUAD) that utilizes m6A/m5C/m1A genes holds immense importance in providing precise prognosis predictions for individuals.

METHODS

This study mined m6A/m5C/m1A-related differential genes in LUAD based on public databases, identified LUAD tumor subtypes based on these genes, and further built a risk prognostic model grounded in differential genes between subtypes. The immune status between high- and low-risk groups was investigated, and the distribution of feature genes in tumor immune cells was analyzed using single-cell analysis. Based on the expression levels of feature genes, a projection of chemotherapeutic and targeted drugs was made for individuals identified as high-risk. Ultimately, cell experiments were further verified.

RESULTS

The 6-gene risk prognosis model based on differential genes between tumor subtypes had good predictive performance. Individuals classified as low-risk exhibited a higher (P < 0.05) abundance of infiltrating immune cells. Feature genes were mainly distributed in tumor immune cells like CD4+T cells, CD8+T cells, and regulatory T cells. Four drugs with relatively low IC50 values were found in the high-risk group: Elesclomol, Pyrimethamine, Saracatinib, and Temsirolimus. In addition, four drugs with significant positive correlation (P < 0.001) between IC50 values and feature gene expression were found, including Alectinib, Estramustine, Brigatinib, and Elesclomol. The low expression of key gene NTSR1 reduced the IC50 value of irinotecan.

CONCLUSION

Based on the m6A/m5C/m1A-related genes in LUAD, LUAD patients were divided into 2 subtypes, and a m6A/m5C/m1A-related LUAD prognostic model was constructed to provide a reference for the prognosis prediction of LUAD.

Destabilizing the genome as a therapeutic strategy to enhance response to immune checkpoint blockade: a systematic review of clinical trials evidence from solid and hematological tumors

Background: Genomic instability is increased alterations in the genome during cell division and is common among most cancer cells. Genome instability enhances the risk of initial carcinogenic transformation, generating new clones of tumor cells, and increases tumor heterogeneity. Although genome instability contributes to malignancy, it is also an "Achilles' heel" that constitutes a therapeutically-exploitable weakness-when sufficiently advanced, it can intrinsically reduce tumor cell survival by creating DNA damage and mutation events that overwhelm the capacity of cancer cells to repair those lesions. Furthermore, it can contribute to extrinsic survival-reducing events by generating mutations that encode new immunogenic antigens capable of being recognized by the immune system, particularly when anti-tumor immunity is boosted by immunotherapy drugs. Here, we describe how genome-destabilization can induce immune activation in cancer patients and systematically review the induction of genome instability exploited clinically, in combination with immune checkpoint blockade. Methods: We performed a systematic review of clinical trials that exploited the combination approach to successfully treat cancers patients. We systematically searched PubMed, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and publication from the reference list of related articles. The most relevant inclusion criteria were peer-reviewed clinical trials published in English. Results: We identified 1,490 studies, among those 164 were clinical trials. A total of 37 clinical trials satisfied the inclusion criteria and were included in the study. The main outcome measurements were overall survival and progression-free survival. The majority of the clinical trials (30 out of 37) showed a significant improvement in patient outcome. Conclusion: The majority of the included clinical trials reported the efficacy of the concept of targeting DNA repair pathway, in combination with immune checkpoint inhibitors, to create a "ring of synergy" to treat cancer with rational combinations.

Current progress in chimeric antigen receptor-modified T cells for the treatment of metastatic breast cancer

Breast cancer is the leading cancer in women. Around 20-30% breast cancer patients undergo invasion or metastasis after radical surgical resection and eventually die. Number of breast cancer patients show poor sensitivity toward treatments despite the advances in chemotherapy, endocrine therapy, and molecular targeted treatments. Therapeutic resistance and tumor recurrence or metastasis develop with the ongoing treatments. Conducive treatment strategies are thus required. Chimeric antigen receptor (CAR)-modified T-cell therapy has progressed as a part of tumor immunotherapy. However, CAR-T treatment has not been effective in solid tumors because of tumor microenvironment complexity, inhibitory effects of extracellular matrix, and lacking ideal tumor antigens. Herein, the prospects of CAR-T cell therapy for metastatic breast cancer are discussed, and the targets for CAR-T therapy in breast cancer (HER-2, C-MET, MSLN, CEA, MUC1, ROR1, EGFR) at clinical level are reviewed. Moreover, solutions are proposed for the challenges of breast cancer CAR-T therapy regarding off-target effects, heterogeneous antigen expression by tumor cells and immunosuppressive tumor microenvironment. Ideas for improving the therapeutics of CAR-T cell therapy in metastatic breast cancer are suggested.

Exosomal PD-L1 confers chemoresistance and promotes tumorigenic properties in esophageal cancer cells via upregulating STAT3/miR-21

Chemotherapy resistance remains a major obstacle in the treatment of esophageal cancer. Previous researches have shown that an increase in exosomal PD-L1 expression was positively associated with a more advanced clinical stage, a poorer prognosis as well as drug resistance in patients with esophageal squamous cell carcinoma (ESCC). To explore the role of exosomal PD-L1 in ESCC, we performed bioinformatics analysis as well as several in vitro/in vivo functional experiments in a parental sensitive cell line EC-9706 and its derivative, a paclitaxel-resistant subline EC-9706R, and found that the exosomal PD-L1 from EC-9706R was higher than that from EC-9706. Moreover, exosomes from EC-9706R significantly increased invasion, migration and chemoresistance of EC-9706. Anti-PD-L1 treatment in combination with chemotherapy also led to reduced tumor burden in vivo. Inhibition of the release of exosomes by GW4869 or inhibition of STAT3 phosphorylation by stattic could effectively reverse the resistance to paclitaxel mediated by exosomal PD-L1. Furthermore, we found that PD-L1, miR-21, and multidrug resistance (MDR1) gene are involved in the process of exosomal transfer. Moreover, PD-L1 could enhance miR-21 expression by increasing the enrichment of STAT3 on miR-21 promoter. Our results suggested that exosomal PD-L1 may contribute to drug resistance to paclitaxel by regulating the STAT3/miR-21/PTEN/Akt axis and promote tumorigenic phenotype. This study provides a novel potential therapeutic approach to reverse chemoresistance and tumor progression through exosomal PD-L1 in ESCC patients.

Long survival after immunotherapy plus paclitaxel in advanced intrahepatic cholangiocarcinoma: A case report and review of literature

BACKGROUND

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary hepatic malignancy worldwide. However, currently available systemic therapies are of limited effectiveness, and the median overall survival of patients treated with first-line standard chemotherapy is less than one year. Immune checkpoint inhibitors have been used to treat solid tumors. Clinical studies recently explored the combination of chemotherapy and immunotherapy for CCA. However, the clinical significance of predictive biomarkers for chemo-immunotherapy in CCA remains unclear. It is also worth exploring whether a combination of chemotherapeutic agents can increase the sensitivity of CCA immunotherapy.

CASE SUMMARY

This study reports a case of advanced iCCA in which clinical complete remission had been achieved using a programmed death 1 (PD-1) inhibitor and paclitaxel without known predictive biomarkers, but with BRCA1, KRAS, and NTRK3 mutations after rapid progression to first-line chemotherapy, and has remained in clinical complete remission for more than two years. This case suggests that chemo-immunotherapy is a potential therapeutic option for patients with iCCA and few known predictive biomarkers for immunotherapies as well as synergistic effect of the combination of paclitaxel and PD-1 monoclonal antibody.

CONCLUSION

The combination of paclitaxel and PD-1 monoclonal antibodyr can be explored in patients with advanced iCCA.

Inhibition of CCCTC Binding Factor-Programmed Cell Death Ligand 1 Axis Suppresses Emergence of Chemoresistance Induced by Gastric Cancer-Derived Mesenchymal Stem Cells

Background

Gastric cancer (GC) is the third leading cause of cancer-associated deaths worldwide. Stromal cells, especially mesenchymal stem cells (MSCs), play significant roles in the development of therapy resistance depending on their paracrine function. The PD-1/PD-L1 crosstalk between cancer and immune cells has been well studied. Emerging evidence suggests that PD-L1 also contributes to tumor resistance to therapy.

Methods

Cell survival and apoptosis were assessed using CCK-8, colony formation, and flow cytometry assays. Protein alterations were analyzed via Western blot. Gene knockdown and overexpression were achieved with siRNA/shRNA and lentiviral infection, respectively. Drug effects on tumors in vivo were assessed with xenografts in nude mice. In addition, GC patient samples after chemotherapy treatment were collected to observe the relationship between chemotherapy effect and CTCF or PD-L1.

Results

In response to 5-fluorouracil or paclitaxel treatment, GCMSC-CM enhanced the cell viability and decreased the apoptosis rate. Furthermore, blocking PD-L1 or CTCF in GC cells prevented GCMSC-induced drug resistance accompanied by a decline in cell stemness. Consistent with these in vitro observations, mice treated with GCMSC-CM showed a lower sensitivity to 5-fluorouracil. In addition, high expression of CTCF and PD-L1 was associated with poor chemotherapy progression in the clinic.

Conclusion

Study results demonstrate a mechanism where GCMSC-CM promotes GC chemoresistance by upregulating CTCF-PD-L1 and provide strong evidence in support of targeting CTCF-PD-L1 signaling as a strategy to prevent resistance in the clinic.