Synergistic antitumor effects of dasatinib and oxaliplatin in gastric cancer cells

Neutrophil extracellular traps-related lncRNAs prognostic signature for gastric cancer and immune infiltration: potential biomarkers for predicting overall survival and clinical therapy

Gastric cancer (GC) is one of the most common digestive tract malignant tumors in the world. At the time of initial diagnosis, it frequently presents with local or distant metastasis, contributing to poor prognosis in patients. Neutrophil extracellular traps (NETs) constitute a mechanism employed by neutrophils that is intricately associated with tumor progression, prognosis, and response to immunotherapy and chemotherapy. Despite this, the specific involvement of NETs-related long non-coding RNAs (lncRNAs) in gastric cancer remains unclear. A prognostic model for NETs-related lncRNAs was constructed through correlation analysis, COX regression analysis, and least absolute shrinkage and selection operator regression (LASSO) analysis. The predictive performance of the model was assessed using Kaplan-Meier survival curves, receiver operating characteristic (ROC) curves, facilitating the exploration of the relationship between disease onset and prognosis in gastric cancer. Additionally, differences in the tumor microenvironment and response to immunotherapy among gastric cancer patients across high- and low-risk groups were analyzed. Furthermore, a prognostic nomogram integrating the risk score with relevant clinicopathological parameters was developed. The prognostic prediction model for gastric cancer, derived from NETs-related lncRNAs in this study, demonstrates robust prognostic capabilities, serving as a valuable adjunct to traditional tumor staging. This model holds promise in offering novel guidelines for the precise treatment of gastric cancer, thereby potentially improving patient outcomes.

Multiaction Pt(IV) Prodrugs Releasing Cisplatin and Dasatinib Are Potent Anticancer and Anti-Invasive Agents Displaying Synergism between the Two Drugs

Herein, we describe the general design, synthesis, characterization, and biological activity of new multitargeting Pt(IV) prodrugs that combine antitumor cisplatin and dasatinib, a potent inhibitor of Src kinase. These prodrugs exhibit impressive antiproliferative and anti-invasive activities in tumor cell lines in both two-dimensional (2D) monolayers of cell cultures and three-dimensional (3D) spheroids. We show that the cisplatin moiety and dasatinib in the investigated Pt(IV) complexes are both involved in the mechanism of action in MCF7 breast cancer cells and act synergistically. Thus, combining dasatinib and cisplatin into one molecule, compared to using individual components in a mix, may bring several advantages, such as significantly higher activity in cancer cell lines and higher selectivity for tumor cells. Most importantly, Pt(IV)-dasatinib complexes hold significant promise for potential anticancer therapies by targeting epithelial-mesenchymal transition, thus preventing the spread and metastasis of tumors, a value unachievable by a simple combination of both individual components.

Development and validation of a novel prognostic lncRNA signature based on the APOBEC3 family genes in gastric cancer

Introduction

Gastric Cancer (GC) refers to a prevalent malignant cancer accompanied by a weak prognosis. The APOBEC3 family genes and lncRNAs are linked with cancer progression. Nevertheless, there is still a scarcity of data concerning the prognostic value of APOBEC3-related lncRNAs in GC.

Methods

We extracted the data from GC samples, including transcriptome as well as clinical data, obtained from the TCGA database. Then, we screened for lncRNAs that were correlated with the APOBEC3 family genes and constructed an APOBEC3-related lncRNA prognostic signature (LPS) by utilizing univariate Cox and lasso regression analysis. Furthermore, we validated our constructed signature and evaluated it thoroughly, including analysis of its function, immunity, mutations, and clinical applications via multiple methods, including Metascape, GSEA, and analyses including TIC and TME, immune checkpoints, CNV and SNPs, Kaplan-Meier survival curves, nomogram, decision tree and drug prediction analysis. Finally, we overexpressed LINC01094 to evaluate the impacts on the proliferation as well as migration with regards to KATO-2 cells.

Results

We selected eight lncRNAs for our APOBEC3-related LPS, which is demonstrated as a valuable tool in predicting the individual GC patients' prognosis. Subsequently, we segregated the samples into subgroups of high-as well as low-risk relying on the risk score with regards to APOBEC3-related LPS. By performing functional analysis, we have shown that immune-as well as tumor-related pathways were enriched in high- and low-risk GC patients. Furthermore, immune analysis revealed a robust correlation between the APOBEC3-related LPS and immunity. We found that immune checkpoints were significantly associated with the APOBEC3-related LPS and were greatly exhibited in GC tumor and high-risk samples. Mutational analysis suggested that the mutational rate was greater in low-risk samples. Furthermore, we predicted small molecular drugs displayed greater sensitivity in patients categorized as high-risk. Moreover, the immune response was also better in high-risk patients. Of these drugs, dasatinib was significant in both methods and might be considered a potential novel drug for treating high-risk GC patients. Finally, we found that LINC01094 has the potential to enhance the migration, proliferation as well as inhibit apoptosis of KATO-2 in GC cells. And Dasatinib has an inhibitory effect on the migration as well as proliferation in GC cells.

Conclusion

We created a novel APOBEC3-related LPS in predicting the prognosis with regards to individual GC patients. Importantly, this APOBEC3-related LPS was closely associated with immunity and might guide clinical treatment.

Study on the role and pharmacology of cuproptosis in gastric cancer

Objective

Gastric cancer has a poor prognosis and high mortality. Cuproptosis, a novel programmed cell death, is rarely studied in gastric cancer. Studying the mechanism of cuproptosis in gastric cancer is conducive to the development of new drugs, improving the prognosis of patients and reducing the burden of disease.

Methods

The TCGA database was used to obtain transcriptome data from gastric cancer tissues and adjacent tissues. GSE66229 was used for external verification. Overlapping genes were obtained by crossing the genes obtained by differential analysis with those related to copper death. Eight characteristic genes were obtained by three dimensionality reduction methods: lasso, SVM, and random forest. ROC and nomogram were used to estimate the diagnostic efficacy of characteristic genes. The CIBERSORT method was used to assess immune infiltration. ConsensusClusterPlus was used for subtype classification. Discovery Studio software conducts molecular docking between drugs and target proteins.

Results

We have established the early diagnosis model of eight characteristic genes (ENTPD3, PDZD4, CNN1, GTPBP4, FPGS, UTP25, CENPW, and FAM111A) for gastric cancer. The results are validated by internal and external data, and the predictive power is good. The subtype classification and immune type analysis of gastric cancer samples were performed based on the consensus clustering method. We identified C2 as an immune subtype and C1 as a non-immune subtype. Small molecule drug targeting based on genes associated with cuproptosis predicts potential therapeutics for gastric cancer. Molecular docking revealed multiple forces between Dasatinib and CNN1.

Conclusion

The candidate drug Dasatinib may be effective in treating gastric cancer by affecting the expression of the cuproptosis signature gene.

Inhibition of BRD4 enhanced the tumor suppression effect of dasatinib in gastric cancer

BRD4, a member of the bromodomain and extraterminal (BET) family, is elevated in multiple cancer tissues, including gastric cancer (GC). Targeted therapy with BRD4 may help improve the overall survival of patients with GC. Meanwhile, the approved multi-target kinase inhibitor, dasatinib, was recently reported to show varied tumor-suppressive effects in GC cells. This study investigated BRD4 expression in vivo and in vitro using immunohistochemistry and western blotting, respectively. We discussed the relationship between BRD4 expression and patient prognosis. Next, the antitumor efficacy of dasatinib was measured in BRD4-knockdown GC cells to determine the role of BRD4 blockage in dasatinib treatment. Finally, molibresib, a BET inhibitor, was used to measure the cooperative function of BRD4 inhibition and dasatinib treatment in three GC cell lines. Epithelial BRD4 expression was higher in tumoral and metastatic tissues and was strongly associated with unfavorable tumor, node, and metastasis stages and survival. BRD4 expression was heterogeneous in the three GC cell lines tested in vitro. In SGC7901, a BRD4-high GC cell line, knockdown of BRD4 using specific siRNAs suppressed cell growth individually and cooperatively with dasatinib. Moreover, molibresib and dasatinib showed a cooperative effect in suppressing the proliferation of BRD4-high GC cells. In conclusion, we confirmed that increased epithelial BRD4 expression is associated with poor disease stage and prognosis in GC and BRD4 blockage might be a valuable strategy to improve the sensitivity of dasatinib and other drugs in the chemotherapy of advanced GC.

pH-responsive nanoprodrugs combining a Src inhibitor and chemotherapy to potentiate antitumor immunity via pyroptosis in head and neck cancer

As the prominent feature of the development and progression of head and neck squamous cell carcinoma (HNSCC) is immunosuppression, therapeutic strategies to restore antitumor immunity have shown promising prospects. The efficacy of chemotherapy, a mainstay in HNSCC treatment, is exemplified by cytotoxic effects as well as immunostimulation, whereas compensatory activation of prosurvival signals in tumor tissues may compromise its efficacy. Aberrant activation of Src is present in many human malignancies including HNSCC, and is implicated in chemotherapy resistance. In this regard, tumor-microenvironment-responsive prodrug nanomicelles (PDO NPs) are rationally designed to combine chemotherapy (oxaliplatin, OXA) and Src inhibitors (dasatinib, DAS) for HNSCC therapy. PDO NPs are constructed by chemically modifying small-molecule prodrugs (DAS-OXA) loaded in block copolymer iPDPA with pH-triggered transforming capability. PDO NPs can controllably release drugs in response to tumor acidity, thus increasing tumor accumulation and therapeutic efficacy. Moreover, PDO NPs can elicit pyroptosis of tumor cells and induce T-cell-mediated antitumor immunity in murine HNSCC models. In summary, nanoprodrugs integrating Src inhibitors enhance the immunological effects of chemotherapy and provide insight into promising approaches for augmenting immunochemotherapy for HNSCC. STATEMENT OF SIGNIFICANCE: In this study, pH-responsive nanomicelles (PDO NPs) were constructed by loading a small molecular prodrug synthesized by the Src inhibitor dasatinib and the chemotherapy drug oxaliplatin into the amphiphilic block copolymer iPDPA to improve the immunological effects of chemotherapy for HNSCC. These nanomicelles can efficiently accumulate in tumor cells and achieve pH-responsive drug release. The PDO NPs can induce pyroptosis of tumor cells and potentiate antitumor immunity in subcutaneous and syngenetic orthotopic HNSCC mouse models, which may present a promising strategy to enhance immunochemotherapy for HNSCC.

Combinatorial Antitumor Activity of Oxaliplatin with Epigenetic Modifying Agents, 5-Aza-CdR and FK228, in Human Gastric Cancer Cells

Epigenetic silencing is considered to be a major mechanism for loss of activity in tumor suppressors. Reversal of epigenetic silencing by using inhibitors of DNA methyltransferase (DNMT) or histone deacetylases (HDACs) such as 5-Aza-CdR and FK228 has shown to enhance cytotoxic activities of several anticancer agents. This study aims to assess the combinatorial effects of gene-silencing reversal agents (5-Aza-CdR and FK228) and oxaliplatin in gastric cancer cells, i.e., Epstein-Barr virus (EBV)-negative SNU-638 and EBV-positive SNU-719 cells. The doublet combinatorial treatment of 5-Aza-CdR and FK228 exhibited synergistic effects in both cell lines, and this was further corroborated by Zta expression induction in SNU-719 cells. Three drug combinations as 5-Aza-CdR/FK228 followed by oxaliplatin, however, resulted in antagonistic effects in both cell lines. Simultaneous treatment with FK228 and oxaliplatin induced synergistic and additive effects in SNU-638 and SNU-719 cells, respectively. Three drug combinations as 5-Aza-CdR prior to FK228/oxaliplatin, however, again resulted in antagonistic effects in both cell lines. This work demonstrated that efficacy of doublet synergistic combination using DNMT or HDACs inhibitors can be compromised by adding the third drug in pre- or post-treatment approach in gastric cancer cells. This implies that the development of clinical trial protocols for triplet combinations using gene-silencing reversal agents should be carefully evaluated in light of their potential antagonistic effects.

Cigarette smoke extract exposure induces EGFR-TKI resistance in EGFR-mutated NSCLC via mediating Src activation and EMT

OBJECTIVES

The study aims to explore the molecular basis for the poor response of epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in EGFR mutated non-small cell lung cancer (NSCLC) patients with smoking history. Novel agent overcoming EGFR-TKI resistance had also been investigated.

METHODS

The impact of cigarette smoke extract (CSE) on gefitinib sensitive PC-9 cells was evaluated using quantitative real-time PCR (qRT-PCR), western blot, CCK-8 assays, immunofluorescence staining, matrigel invasion assays and wound healing assays.

RESULTS

Western blot and qRT-PCR presented that CSE stimulated the up-regulation of Vimentin and down-regulation of E-cadherin in PC-9 cells in concentration-and time-dependent manners through modulating Src phosphorylation. N-acetylcysteine (NAC) was capable of decreasing Src phosphorylation, abrogating changes of epithelial to mesenchymal transition (EMT) markers instigated by CSE. Immunofluorescence staining found that PC-9 cells displayed features of mesenchymal cells after CSE exposure, while PP2 and NAC could recover these changes. CCK-8 assays showed that CSE could increase the IC50 of PC-9 cells, while PP2 and NAC could abort the elevation of IC50 caused by CSE. Matrigel invasion assays and wound healing assays showed that CSE could increase the invasion and migration ability of PC-9 cells, which could be suppressed by NAC and PP2.

CONCLUSION

CSE exposure induced EGFR-TKI resistance via mediating Src activation and EMT in NSCLC. NAC may alleviate smoking induced EGFR-TKI resistance through inhibiting Src activation and EMT reversal. NAC may be a promising adjuvant to reinforce the effect of EGFR-TKI.

Capecitabine metronomic chemotherapy inhibits the proliferation of gastric cancer cells through anti-angiogenesis

To evaluate the inhibitory effect and mechanism of capecitabine metronomic chemotherapy on gastric cancer cells. In vitro, the effects of 5-fluorouracil (Fu) metronomic chemotherapy on proliferation, apoptosis, tube formation ability, and angiogenesis were detected. In vivo, Ki-67, CD34 and VEGF were detected by immunohistochemical staining (IHC). Flow cytometry was used to detect the percentage of circulating endothelial progenitors (CEPs), and VEGF and PDGF were detected by ELISA in the peripheral blood of nude mice. The proliferation of the SGC-7901 and AGS gastric cancer cell lines in the metronomic 5-Fu group was decreased compared with the control group in vitro. The total length of the small tubes and tubular junction numbers were significantly lower in the metronomic group than the control group. The VEGF and PDGF levels in the cell culture supernatants were lower in the metronomic group than the control group. Compared with the control group, the CEP percentage was decreased in the peripheral blood of tumor-bearing nude mice following treatment with metronomic 5-Fu or capecitabine chemotherapy. No significant changes were found in the conventional or control group. In the peripheral blood of tumor-bearing nude mice, the VEGF and PDGF levels were decreased in the metronomic groups. Metronomic 5-Fu inhibited the proliferation of gastric cancer cells in vitro and in vivo, and their antitumor effects were non-inferior to those of conventional dose chemotherapy, with mild side effects. Thus, tumor inhibition may be attributed to anti-angiogenesis.

Mechanisms of resistance to BCR-ABL TKIs and the therapeutic strategies: A review

BCR-ABL caused by the translocation of t(9,22) with elevated tyrosine-kinase activity could induce leukemia in mice, which established BCR-ABL as the molecular pathogenic event in CML (Chronic myeloid leukemia). In recent years, a variety of tyrosine kinase inhibitors (TKIs) targeting at BCR-ABL specifically and effectively have been developed, which has fundamentally promoted the treatment of CML. However, the efficacy of TKIs was limited by its resistance induced by the development of kinase domain mutations and other mechanisms illustrated. In this review, we summarized BCR-ABL inhibitors approved by Food and Drug Administration (FAD), with the same concerns focus on the resistant mechanisms of BCR-ABL inhibitors and therapeutic resistant strategies.

Suberoylanilide hydroxamic acid enhances the antitumor activity of oxaliplatin by reversing the oxaliplatin‑induced Src activation in gastric cancer cells

Oxaliplatin and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA), also known as vorinostat, are potent antitumor agents. The aim of this study was to investigate the effect of SAHA on the antitumor efficacy of oxaliplatin in gastric cancer and the interaction between oxaliplatin and SAHA. Cell growth inhibition was evaluated using Cell Counting Kit‑8 and colony formation assays. Xenografts established in nude mice were used to assess tumor growth in vivo. Western blot analysis was used to detect the expression of acetyl‑histone H3, phosphorylated histone H2AX (γH2AX), B‑cell lymphoma 2 (Bcl‑2), cleaved caspase‑3, cleaved poly (ADP‑ribose) polymerase (PARP), phosphorylated- (p-)Src, Src, Akt and p‑Akt in gastric cancer cells. The in vitro growth of SGC‑7901, Hs746T and MKN28 gastric cancer cells was found to be dose‑dependently inhibited by oxaliplatin and SAHA. Furthermore, combined treatment was observed to be more effective in inhibiting cancer cell growth and colony formation than monotherapy. Similar effects were found in the xenografts. A positive interaction was identified between oxaliplatin and SAHA (between‑subject effects of oxaliplatin and SAHA, P<0.001). In addition, combined exposure to oxaliplatin and SAHA increased γH2AX expression and decreased Bcl‑2 expression. The expression of cleaved caspase‑3 and PARP was also increased with combination treatment. Oxaliplatin‑induced Src phosphorylation was detected in gastric cancer cells, as we have previously reported. However, this effect was inhibited by SAHA. The oxaliplatin‑induced Src phosphorylation was not impaired with Akt inhibition. In conclusion, oxaliplatin and SAHA exhibited a positive interaction when used in combination and were found to suppress gastric cancer cell survival and growth. The reversal of oxaliplatin‑induced Src activation may be responsible for this positive interaction.