CDKN2B is critical for verapamil-mediated reversal of doxorubicin resistance in hepatocellular carcinoma

A CDKN2B-Associated Immune Prognostic Model for Predicting Immune Cell Infiltration and Prognosis in Esophageal Carcinoma

Objective

Studies have indicated that cyclin dependent protein kinase inhibitor 2B (CDKN2B) deletion is one of the most common changes in esophageal cancer (EC) which affects its progression and prognosis. This study explored the association between CDKN2B deletion, immunophenotype, and the prognosis of EC.

Methods

We investigated CDKN2B status and RNA expression, identified differentially expressed immune-associated genes between wild-type CDKN2B (CDKN2BWT) and deleted CDKN2B (CDKN2Bdeletion) in Cancer Genome Atlas (TCGA) EC samples. We also a constructed an immune prognostic model (IPM) based on these genes. Thereafter, the effects of IPM on the immune microenvironment of EC were analyzed. Finally, we established a nomogram by integrating the IPM and other clinical factors.

Results

CDKN2B deletion leads to downregulation of the immune response in EC. A total of 136 immune-associated genes were identified based on the CDKN2B deletion status, and three genes with remarkable potential as individual targets were selected for model construction. An IPM was developed and validated, it showed good performance in differentiating patients with a low or high risk of poor prognosis, and its predictive ability was independent of traditional clinical features. High-risk patients with EC had increased T follicular helper cells (Tfh) and M0 macrophages, and lower infiltration levels of resting CD4 memory T cells resting, and naive B cells. The nomogram developed for clinical application showed good predictive performance.

Conclusions

Our results suggested that CDKN2B deletion was associated with the survival and immune microenvironment in EC. IPM is not only an effective indicator of the immune response and prognosis, but also suggest potential targets for immunotherapy in patients with EC.

Chemosensitizer Loaded NIR-Responsive Nanostructured Lipid Carriers: A Tool for Drug-Resistant Breast Cancer Synergistic Therapy

Although numerous technical advances have been made in cancer treatment, chemotherapy is still a viable treatment option. However, it is more effective when used in combination with photothermal therapy for resistant breast cancer cells. This study introduces a smart drug delivery system, (DOX-OA+VERA+AuNRs)@NLC, which is designed for dual chemo/photothermal therapy of multiple-drug-resistant breast cancer. Type-III nanostructured lipid carriers (NLCs) were used as drug delivery systems, where nano-in-nano structures offer several advantages. Doxorubicin (DOX) was used as the antitumor agent by ion-pairing it with oleic acid (OA) to increase the DOX loading capacity, as well as to reduce the burst release of the drug. Verapamil (VERA), which was used as a chemosensitizer to overcome the multiple-drug resistance, was co-loaded with DOX-OA. Gold nanorods (AuNRs) were exploited as the photothermal therapy agent in photothermal therapy (PTT) application, which would have a synergistic relation with chemotherapy. The release of DOX-OA and VERA from NLCs was studied in vitro by triggering with NIR laser irradiation. Thus, an all-in-one drug delivery system was designed to release the active pharmaceutical ingredients (APIs) at higher concentrations in the desired region and provide both chemo/PTT. Besides, the application of a folic acid-chitosan (FA-CS) coating to NLCs has facilitated the development of systems capable of targeting and specifically releasing their cargo within cancerous tissues while preserving their surrounding environment.

Targeting Hepatic Cancer Stem Cells (CSCs) and Related Drug Resistance by Small Interfering RNA (siRNA)

Tumor recurrence after curative therapy and hepatocellular carcinoma (HCC) cells' resistance to conventional therapies is the reasons for the worse clinical results of HCC patients. A tiny population of cancer cells with a strong potential for self-renewal, differentiation, and tumorigenesis has been identified as cancer stem cells (CSCs). The discovery of CSC surface markers and the separation of CSC subpopulations from HCC cells have been made possible by recent developments in the study of hepatic (liver) CSCs. Hepatic CSC surface markers include epithelial cell adhesion molecules (EpCAM), CD133, CD90, CD13, CD44, OV-6, ALDH, and K19. CSCs have a significant influence on the development of cancer, invasiveness, self-renewal, metastasis, and drug resistance in HCC, and thus provide a therapeutic chance to treat HCC and avoid its recurrence. Therefore, it is essential to develop treatment approaches that specifically and effectively target hepatic stem cells. Given this, one potential treatment approach is to use particular small interfering RNA (siRNA) to target CSC, disrupting their behavior and microenvironment as well as changing their epigenetic state. The characteristics of CSCs in HCC are outlined in this study, along with new treatment approaches based on siRNA that may be used to target hepatic CSCs and overcome HCC resistance to traditional therapies.

Investigating the combinatory effect of Sclerocarya birrea with doxorubicin against selected colorectal cancer cell lines

Introduction

Colorectal cancer incidences continue to increase annually, worldwide. Herbal plants with antiproliferative properties received research interest as agents that can be adjuvant therapies with chemotherapy drugs to enhance their efficacy and reverse drug resistance.

Methods

Sclerocarya birrea ethanolic (SBE) and aqueous (SBW) extracts combined with doxorubicin (DOX) against drug-sensitive and drug-resistant colorectal cancer cells were investigated for their potential adjuvant and drug resistance reversal. The extracts were assessed for their potential anticancer activities on HCT15 and HT29 cell lines as well as their doxorubicin potentiating and drug resistance reversal effects respectively. The extracts were assessed for their cytotoxicity on normal 3T3-L1 fibroblast cells.

Results

Both SBE and SBW extracts exhibited no toxicity against normal 3T3 cells and showed low activity on the HT29 cell line. Contrarily, resistant HCT15 cells showed moderate to low activity with significantly higher inhibitory concentration (IC)50 values. The combination of SBE with DOX and SBW with DOX resulted in antagonistic interactions, causing an increase in IC50 values for HT29 and HCT15 cells. In contrast, the combination of DOX and verapamil (VER) produced an additive effect, with no change in their IC50 values.

Conclusion

Based on the findings from the combination treatment, the SBE and SBW extracts demonstrated higher efficacy and synergistic effects combined with DOX at IC75 compared to the combination of DOX and VER, suggesting their potential as anticancer agents. However, further research on both the SBE and SBW extracts' mechanisms of action and in vivo effects is warranted.

Construction of a Novel Oxidative Stress Response-Related Gene Signature for Predicting the Prognosis and Therapeutic Responses in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy with poor outcomes, and the assessment of its prognosis as well as its response to therapy is still challenging. In this study, we aimed to construct an oxidative stress response-related genes-(OSRGs-) based gene signature for predicting prognosis and estimating treatment response in patients with HCC. We integrated the transcriptomic data and clinicopathological information of HCC patients from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) databases. LASSO Cox regression analysis was utilized to establish an integrated multigene signature in the TCGA cohort, and its prediction performance was validated in the ICGC cohort. The CIBERSORT algorithm was employed to evaluate immune cell infiltration. The response rate to immune checkpoint inhibition (ICI) therapy was assessed using a TIDE platform. Drug activity data from the Cancer Genome Project and NCI-60 human cancer cell lines were used to predict sensitivity to chemotherapy. We successfully established a gene signature comprising G6PD, MT3, CBX2, CDKN2B, CCNA2, MAPT, EZH2, and SLC7A11. The risk score of each patient, which was determined by the multigene signature, was identified as an independent prognostic marker. The immune cell infiltration patterns, response rates to ICI therapy, and the estimated sensitivity of 89 chemotherapeutic drugs were associated with risk scores. Individual prognostic genes were also associated with susceptibility to various FDA-approved drugs. Our study indicates that a comprehensive transcriptomic analysis of OSRGs can provide a reliable molecular model to predict prognosis and therapeutic response in patients with HCC.

The Cancer Stem Cell in Hepatocellular Carcinoma

The recognition of intra-tumoral cellular heterogeneity has given way to the concept of the cancer stem cell (CSC). According to this concept, CSCs are able to self-renew and differentiate into all of the cancer cell lineages present within the tumor, placing the CSC at the top of a hierarchical tree. The observation that these cells—in contrast to bulk tumor cells—are able to exclusively initiate new tumors, initiate metastatic spread and resist chemotherapy implies that CSCs are solely responsible for tumor recurrence and should be therapeutically targeted. Toward this end, dissecting and understanding the biology of CSCs should translate into new clinical therapeutic approaches. In this article, we review the CSC concept in cancer, with a special focus on hepatocellular carcinoma.

Cyclin-dependent kinase inhibitor 2B gene is associated with the sensitivity of hepatoma cells to Sorafenib

Purpose: The sensitivity of advanced hepatocellular carcinoma (HCC) to Sorafenib is low. The purpose of this study was to investigate the effects of cyclin-dependent kinase inhibitor 2B (CDKN2B) gene on the prognosis of HCC and the sensitivity of HCC cells to Sorafenib. Patients and methods: Streptavidin-perosidase (SP) staining was performed to determine the expression of CDKN2B in HCC tissues and adjacent tissues. The cell counting kit-8 (CCK-8) assay was carried out to determine cell viability. CDKN2B mRNA and protein were tested by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot, respectively. CDKN2B gene was silenced or over-expressed in the cells by plasmid transfection technique. Flow cytometry was carried out to detect cell cycle and apoptosis. Results: SP staining results showed that CDKN2B was positive in adjacent tissues and in HCC tissues from partial response (PR) patients, CDKN2B was slightly positive in stable disease (SD) patients, but negative in progression disease (PD) patients. The survival rate of patients with low expression of CDKN2B was low. Up-regulation of CDKN2B expression could promote the pro-apoptotic effect of Sorafenib and cell arrest in G1 phase. When the CDKN2B gene expression was down-regulated, the cell apoptosis rate and the proportion of cells treated with Sorafenib in G1 phase decreased. Silencing CDKN2B reversed CDKN2B overexpression caused by Sorafenib. Conclusion: CDKN2B genes were lowly expressed in tumor tissues from HCC patients who were treated with Sorafenib and had a poor prognosis. Up-regulation of CDKN2B promoted sensitivity of HCC to Sorafenib, and similarly down-regulation of CDKN2B reduced the sensitivity.

Synergistic effect of paclitaxel and verapamil to overcome multi-drug resistance in breast cancer cells

BACKGROUND

The aim of this study was to investigate the synergistic effect of paclitaxel (PTX) and verapamil (VERA) on adriamycin (ADR)-resistant breast cancer (MCF-7/ADR) cells.

METHODS

ATP-PCA was applied to determine the inhibitory effects of PTX combined with VERA on MCF-7/ADR cells. Edu, CCK-8 and Flow cytometry (FCM), Annexin V-FITC binding and Western blot were used to analyze the effects of combination therapy with PTX and VERA on cell proliferation, progression of cell cycle and cell apoptosis.

RESULTS

PTX-based treatments with VERA enhanced killing effect on MCF-7/ADR cells. IC₅₀ value of cell was significantly decreased in combination treatment compared with PTX administrated. VERA enhanced the efficacy and sensitivity of PTX to MCF-7/ADR cells. Combination of PTX and VERA could inhibit cell proliferation via arresting progression of cell cycle and promote cell apoptosis.

CONCLUSION

PTX, along with VERA, had a synergistic action in anti-tumor response and may be proposed as a novel treatment strategy for chemo-resistant breast cancer.

Upregulation of Ubiquitin Carboxyl-Terminal Hydrolase L1 (UCHL1) Mediates the Reversal Effect of Verapamil on Chemo-Resistance to Adriamycin of Hepatocellular Carcinoma

BACKGROUND The aim of this study was to investigate the role of ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) in the reversal effect of verapamil (VER) on chemo-resistance to Adriamycin (ADM) in treatment of hepatocellular carcinoma (HCC). MATERIAL AND METHODS HCC cell lines SMMC-7721 and BEL-7402 were used as model cell lines. High-throughput transcriptome sequencing based on Illumina technology was used to screen whether UCHL1 mediated the reversal effect of VER on chemo-resistance. Quantitative real-time PCR (qRT-PCR) was performed to determine the expression level of UCHL1 mRNA in HCC cells, and western blot analysis was performed to examine the protein expression of UCHL1 protein in HCC cells. Immunohistochemistry assay was performed to determine the protein expression of UCHL1 in tissue samples from patients presenting with either positive or negative responses to the reversal therapeutic regimen of VER. Moreover, cell models with UCHL1 knockdown and overexpression were established to examine the reversal effect of VER on chemo-resistance to ADM in HCC cells. Cell apoptosis was determined by flow cytometry following Annexin V-PI staining. RESULTS The expression levels of UCHL1 genes correlated with the level of apoptosis induced by ADM+VER. Overexpression of UCHL1 genes promoted apoptosis in cells treated with VER+ADM. UCHL1 knockdown using siRNA weakened the effect of ADM+VER, indicating that ADM+VER promotes HCC cell apoptosis and that UCHL1 genes participate in VER-mediated promotion in tumor cell apoptosis. CONCLUSIONS Upregulation of UCHL1 enhanced the reversal effect of VER on chemo-resistance to ADM and promoted cell apoptosis. The underlying mechanism of the function of UCHL1 and the signaling pathway involved in its effect are to be investigated in our future research.