Drug Resistance Pathways Research Articles

TLR-9 agonist CpG activates macrophages and modulates expression of microRNAs involved in cancer drug resistance and various signaling pathways

Abstract TLR-9 agonist, CpG induces pro-inflammatory immune response. We studied the immune response elicited in C57Bl/6 female mice by repeated stimulation of TLR-9 through multiple doses of CpG administration. Complete blood count analysis after CpG treatment revealed peripheral pancytopenia and the spleen showed splenomegaly. Flow cytometry analyses of spleen and liver mononuclear cells disclosed macrophage activation, evidenced by substantial increase in F4/80+ cells in the treatment group compared to control. Analysis of serum by ELISA demonstrated enhanced levels of pro-inflammatory cytokines, IL12/23, IL6 and TNFα in the CpG-treated group whereas no significant change was observed in the amount of anti-inflammatory cytokine, IL10. The spleen cells were further subjected to microarray analysis in order to examine the modulation of microRNA expression pattern following CpG treatment. Investigation of miRNA-mRNA relationships using the ingenuity pathway analysis (IPA) revealed differential expression of miRNAs associated with cancer drug resistance, HOTAIR and BAG signaling pathways along with microRNAs involved in immunomodulation. The major microRNAs altered with CpG treatment included mir27a, mir181, mir130a, mir487a, mir29b1, mir130a, mir3473b, mir21a, mir142 and mir144 targeting genes involved in drug resistance, apoptosis, cell cycle, angiogenesis and major histocompatibility complex-related proteins. Together, our studies demonstrate that chronic macrophage activation may lead to uncontrolled activation and proliferation of immune cells. (Supported by NIH grants P01AT003961, P20GM103641, R01AI129788, R01ES030144, R01AI160896 and R01AI123947). Supported by NIH grants P01AT003961, P20GM103641, R01AI129788, R01ES030144, R01AI160896 and R01AI123947

Role of the Bone Marrow Microenvironment in Drug Resistance of Hematological Malignances.

The unique features of the tumor microenvironment (TME) govern the biological properties of many cancers, including hematological malignancies. TME factors can trigger an invasion and protect against drug cytotoxicity by inhibiting apoptosis and activating specific signaling pathways (e.g. NF-ΚB). TME remodeling is facilitated due to the high self-renewal ability of the bone marrow. Progressing tumor cells can alter some extracellular matrix (ECM) components which act as a barrier to drug penetration in the TME. The initial progression of the cell cycle is controlled by the MAPK pathway (Raf/MEK/ERK) and Hippo pathway, while the final phase is regulated by the PI3K/Akt /mTOR and WNT pathways. This review summarizes the main signaling pathways involved in drug resistance (DR) and some mechanisms by which DR can occur in the bone marrow. The relationship between autophagy, endoplasmic reticulum stress, and cellular signaling pathways in DR and apoptosis is covered in the TME.

Abstract P2-03-03: The comparison of genomic alteration characteristics of young women with breast cancer between Chinese and Western population

Abstract Background: With the increase in incidence rate of breast cancer, the number of young women with breast cancer (YWBC) is rapidly augmented. As YWBC have practical needs for breast conservation and fertility, they are deserved special attention. Previous study indicated that the proportion of YWBC in China patients with breast cancer was higher than that in Western patients with breast cancer. Objective: The purpose of this study was to evaluate the genomic alteration characteristics in Chinese YWBC when compared to Western YWBC. Methods: Genomic alternations were assessed by targeted next-generation sequencing (tNGS, a 450-gene panel) using breast cancer samples collected from 71 Chinese YWBC (≤35 years old). The data of genomic alternations in Chinese YWBC was compared with that in 200 Western YWBC (≤35 years old) from Memorial Sloan-Kettering Cancer Center (MSKCC) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC). Results: The median age of the enrolled Chinese YWBC was 31 (20-35) years old. Among them, 42.2% (30/71) were at I-II stages, 46.5% (33/71) were at III-IV stage, and the stage of 11.3% (8/71) patients was unknown. Thirty-one cases were HR+/HER2-, 14 cases were HER2+, 13 cases were triple-negative (TNBC), and the remaining 13 cases were unknown. As for the Western cohort, the median age was 32 (21- 35) years old. Half of the patients (53.0%, 106/200) were I-II stage and 35.5% (71/200) were III-IV stage. Ninety-nine cases were HR+/HER2-, 27 cases were HER2+, 46 cases were TNBC. Top 8 genes with high mutation frequencies in Chinese YWBC were TP53 (60.6%), PIK3CA (39.4%), GATA3 (22.5%), ERBB2 (21.1%), CDK12 (18.3%), MYC (16.9%), FGF19 (15.5%) and FGFR1 (15.5%). Substitution/indel and gene amplification were the common alternation types. In the Western YWBC, TP53 (53.5%), PIK3CA (23.5%), and GATA3 (18.5%) were equally the top 3 mutated genes, whereas ARID1A (7.5%), ESR1 (7.5%), MUC16 (7.0%), PTEN (6.0%), ERBB2 (5.5%) were top 4th to 8th mutated genes, which were different to that in Chinese YWBC. Moreover, 20 mutated genes with significantly different mutation frequencies were screened out in Chinese YWBC when compared to Western patients (P<0.05), including CDK12 (16.9% vs 1.0%, P<0.0001, respectively), MYC (16.9% vs 1.1%, P<0.0001, respectively), FGFR1 (15.5% vs 1.5%, P<0.0001, respectively), FGF4 (11.3% vs 0.50%, P=0.0001, respectively), KMT2C (15.5% vs 2.0%, P=0.0001, respectively). These differentially mutated genes were mainly enriched in longevity pathway, drug resistance pathway and cell cycle related pathway. With further combining with molecular typing analysis, 13 (65.0%) different mutation genes were found to be significantly different in Chinese and Western populations, namely, FGF4, FGFR1, KMT2C, SPEN, CDKN2A, GNAS, NCOR1, NF1, BAP1, NBN, PIK3CA and EGFR. In addition, 13 (18.3%) of Chinese YWBC possessed germline mutations, and 1 of them was present in each patient. Among the 13 germline mutations, 5 were pathogenic and 8 were pathogenic-like. Germline mutations mainly occurred in homologous recombination pathway, including four mutations in BRCA1, two in RAD51D; BRCA2, PALB2, FANCA, FANCC and NBN harboring one mutation each. Germline mutations were unavailable in Western populations. Conclusion: The present study demonstrated that the gene mutation profile was significantly different between Chinese YWBC and Western YWBC, suggesting that different diagnostic and/or therapeutic strategy should be considered in Chinese YWBC when compared to Western YWBC. Citation Format: Hong Liu, Jinpu Yu, Zanmei Xu, Fei Wang, Yang Li, Siyue Zhang, Bin Wang, Beibei Yang, Xuesong Li. The comparison of genomic alteration characteristics of young women with breast cancer between Chinese and Western population [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-03-03.

2‑Cl‑IB‑MECA regulates the proliferative and drug resistance pathways, and facilitates chemosensitivity in pancreatic and liver cancer cell lines.

Specific A3 adenosine receptor (A3AR) agonist, 2-chloro-N6-(3-iodobenzyl)-5′-N-methylcarboxamidoadenosine (2-Cl-IB-MECA), demonstrates anti-proliferative effects on various types of tumor. In the present study, the cytotoxicity of 2-Cl-IB-MECA was analyzed in a panel of tumor and non-tumor cell lines and its anticancer mechanisms in JoPaca-1 pancreatic and Hep-3B hepatocellular carcinoma cell lines were also investigated. Initially, decreased tumor cell proliferation, cell accumulation in the G1 phase and inhibition of DNA and RNA synthesis was found. Furthermore, western blot analysis showed decreased protein expression level of β-catenin, patched1 (Ptch1) and glioma-associated oncogene homolog zinc finger protein 1 (Gli1), which are components of the Wnt/β-catenin and Sonic hedgehog/Ptch/Gli transduction pathways. In concordance with these findings, the protein expression levels of cyclin D1 and c-Myc were reduced. Using a luciferase assay, it was revealed for the first time a decrease in β-catenin transcriptional activity, as an early event following 2-Cl-IB-MECA treatment. In addition, the protein expression levels of multidrug resistance-associated protein 1 and P-glycoprotein (P-gp) were reduced and the P-gp xenobiotic efflux function was also reduced. Next, the enhancing effects of 2-Cl-IB-MECA on the cytotoxicity of conventional chemotherapy was investigated. It was found that 2-Cl-IB-MECA enhanced carboplatin and doxorubicin cytotoxic effects in the JoPaca-1 and Hep-3B cell lines, and a greater synergy was found in the highly tumorigenic JoPaca-1 cell line. This provides a novel in vitro rationale for the utiliza- tion of 2-Cl-IB-MECA in combination with chemotherapeutic agents, not only for hepatocellular carcinoma, but also for pancreatic cancer. Other currently used conventional chemo- therapeutics, fluorouracil and gemcitabine, showed synergy only when combined with high doses of 2-Cl-IB-MECA. Notably, experiments with A3AR-specific antagonist, N-[9-Chloro-2-(2-furanyl)(1,2,4)-triazolo(1,5-c)quinazolin-5-yl] benzene acetamide, revealed that 2-Cl-IB-MECA had antitumor effects via both A3AR-dependent and -independent pathways. In conclusion, the present study identified novel antitumor mechanisms of 2-Cl-IB-MECA in pancreatic and hepatocellular carcinoma in vitro that further underscores the importance of A3AR agonists in cancer therapy.

Sunitinib induced resistance of endothelial cells by up-regulating P-glycoprotein and PI3K/Akt pathway

Drug resistance is a crucial obstacle to achieve satisfactory chemotherapeutic effects. Numerous studies have shown that the PI3K/Akt signaling pathway plays a significant role in various processes of cellular events and tumor progression, while few studies have focused on the PI3K/Akt signaling pathway in drug resistance of endothelial cells. The present study aims to explore the relationship of PI3K/Akt signaling and cellular resistance to anticancer drugs in human microvessel endothelial cells (HMEC-1). We established stable sunitinib-resiatant human microvessel endothelial cells (HMEC-su) after long-term exposure to sunitinib (a small-molecule tyrosine kinase receptor inhibitor) for 12 months. HMEC-su showed significant alternations of cell morphology and exhibited a 2.32-fold higher IC50 of sunitinib than parental HMEC-1 cells. Expression of P-glycoprotein (P-gp) and breast cancer-resistance protein (ABCG2) which mediates drug efflux, increased significantly in HMEC-su lines compared with HMEC-1 cells by western blots assay. Our study further demonstrates that LY294002 (blocking the PI3K/Akt pathway) enhances the sensibility of HMEC-su to suntinib and inhibits the gene transcription and protein expression of P-gp, ABCG2 in HMEC-su cells. In conclusion, these results indicate that LY294002 could reverse P-gp and ABCG2 mediated-drug resistance to sunitinib in HMEC-su cells by inhibiting PI3K/Akt signaling.

Multicellular biomarkers of drug resistance as promising targets for glioma precision medicine and predictors of patient survival.

Aim: This study aimed to translate a known drug-resistance mechanism of long-term CSF1R inhibition into multicellular biomarkers that can serve as potential therapeutic targets as well as predictive markers for the survival of glioma patients.Methods: Using existing data from a published mouse study of drug resistance in immunotherapy for glioma, we identified multicellular differentially expressed genes (DEGs) between drug-sensitive and drug-resistant mice and translated the DEGs in mouse genome to human homolog. We constructed correlation gene networks for drug resistance in mice and glioma patients and selected candidate genes via concordance analysis of human with mouse gene networks. Markers of drug resistance and an associated predictive signature for patient survival were developed using regularized Cox models with data of glioma patients from The Cancer Genome Atlas (TCGA) database. Predictive performance of the identified predictive signature was evaluated using an independent human dataset from the Chinese Glioma Genome Atlas (CGGA) database.Results: Fourteen genes (CCL22, ADCY2, PDK1, ZFP36, CP, CD2, PLAUR, ACAP1, COL5A1, FAM83D, PBK, FANCA, ANXA7, and TACC3) were identified as genetic biomarkers that were all associated with pathways in glioma progression and drug resistance. Five of the 14 genes (CCL22, ADCY2, PDK1, CD2, and COL5A1) were used to construct a signature that is predictive of patient survival in the proneural subtype GBM patients with an AUC under the time-dependent receiver operating characteristic (ROC) of 2-year survival equal to 0.89. This signature also shows promising predictive accuracy for the survival of LGG patients but not for non-proneural type GBMs.Conclusion: Our translational approach can utilize gene correlation networks from multiple types of cells in the tumor microenvironment of animals. The identified biomarkers of drug resistance have good power to predict patient survival in some major subtypes of gliomas (the proneural subtype of GBM and LGG). The expression levels of the biomarkers of drug resistance may be modified for the development of personalized immunotherapies to prolong survival for a large portion of glioma patients.

Targeting the complement system in pancreatic cancer drug resistance: a novel therapeutic approach.

Pancreatic cancer is ranked as the fourth leading cause of cancer-related mortality and is predicted to become the second leading cause of cancer-related death by 2030. The cause of this high mortality rate is due to pancreatic ductal adenocarcinoma’s rapid progression and metastasis, and development of drug resistance. Today, cancer immunotherapy is becoming a strong candidate to not only treat various cancers but also to combat against chemoresistance. Studies have suggested that complement system pathways play an important role in cancer progression and chemoresistance, especially in pancreatic cancer. A recent report also suggested that several signaling pathways play an important role in causing chemoresistance in pancreatic cancer, major ones including nuclear factor kappa B, signal transducer and activator of transcription 3, c-mesenchymal-epithelial transition factor, and phosphoinositide-3-kinase/protein kinase B. In addition, it has also been proven that the complement system has a very active role in establishing the tumor microenvironment, which would aid in promoting tumorigenesis, progression, metastasis, and recurrence. Interestingly, it has been shown that the downstream products of the complement system directly upregulate inflammatory mediators, which in turn activate these chemo-resistant pathways. Therefore, targeting complement pathways could be an innovative approach to combat against pancreatic cancer drugs resistance. In this review, we have discussed the role of complement system pathways in pancreatic cancer drug resistance and a special focus on the complement as a therapeutic target in pancreatic cancer.

Cholesterol Depletion Modulates Drug Resistance Pathways to Sensitize Resistant Breast Cancer Cells to Tamoxifen

Cancer drug resistance poses a significant risk of relapse and mortality. Adjuvant tamoxifen use has significantly reduced breast cancer mortality; however, many patients relapse due to acquired resistance. We aim to assess the potential of a cholesterol depletor (acetyl plumbagin) combined with tamoxifen to reduce cholesterol accumulation and cancer drug resistance. Cell viability, apoptosis and cholesterol staining was assessed following combination treatment. Gene and protein expression in cancer drug resistance and lipoprotein signalling pathways were assessed using RT2 Profiler™ PCR arrays and STRING networks. Combined treatment led to an increase in apoptosis and reduced intracellular cholesterol in MCF-7 and long-term estrogen deprived (LTED) cells compared to single compound treatments. Furthermore, the combination treatment perturbed several cholesterol-related and cancer-drug resistance pathways. The present study demonstrates the efficacy of tamoxifen combined with acetyl plumbagin in potentially disrupting the PI3K/Akt/PKB and Akt/mTORC1 signalling pathways in MCF-7 cells, reducing breast cancer cell proliferation and resistance.

Network pharmacology reveals the potential mechanism of Baiying Qinghou decoction in treating laryngeal squamous cell carcinoma.

Context: Baiying Qinghou as a traditional Chinese medicine decoction shows anticancer property on laryngeal squamous cell carcinoma. However, little is known about the precise mechanism of Baiying Qinghou detection against laryngeal squamous cell carcinoma.Objective: This study was aimed to explore potential mechanism of therapeutic actions of Baiying Qinghou decoction on laryngeal squamous cell carcinoma.Materials and Methods: The active chemical components of Baiying Qinghou decoction were predicted, followed by integrated analysis of network pharmacology and molecular docking approach. The network pharmacology approach included target protein prediction, protein-protein interaction network construction and functional enrichment analysis.Results: Sitosterol and quercetin were predicted to be the overlapped active ingredients among three Chinese herbs of Baiying Qinghou decoction. The target proteins were closely associated with response to chemical, response to drug related biological process and cancer related pathways such as PI3K-Akt signaling, HIF-1 signaling and Estrogen signaling pathway. The target proteins of TP53, EGFR, PTGS2, NOS3 and IL1B as the key nodes in PPI network were cross-validated, among which EGFR, IL1B, NOS3 and TP53 were significantly correlated with the prognosis of patients with laryngeal squamous cell carcinoma. Finally, the binding modes of EGFR, IL1B, NOS3 and TP53 with quercetin were visualized.Discussion and Conclusion: Quercetin of Baiying Qinghou decoction showed therapeutic effect against laryngeal squamous cell carcinoma by regulating TP53, EGFR, NOS3 and IL1B involved with drug resistance and PI3K-AKT signaling pathway. TP53, EGFR, NOS3 and IL1B may be the candidate targets for the treatment of laryngeal squamous cell carcinoma.

Increased expression of Rho-associated protein kinase 2 confers astroglial Stat3 pathway activation during epileptogenesis

Patients with TLE are prone to tolerance to antiepileptic drugs. Based on the perspective of molecular targets for drug resistance, it is necessary to explore effective drug resistant genes and signaling pathways for the treatment of TLE. We performed gene expression profiles in hippocampus of patients with drug-resistant TLE and identified ROCK2 as one of the 20 most significantly increased genes in hippocampus. In vitro and in vivo experiments were performed to identify the potential role of ROCK2 in epileptogenesis. In addition, the activity of Stat3 pathway was tested in rat hippocampal tissues and primary cultured astrocytes. The expression levels of ROCK2 in the hippocampus of TLE patients were significantly increased compared with the control group, which was due to the hypomethylation of ROCK2 promoter. Fasudil, a specific Rho-kinase inhibitor, alleviated epileptic seizures in the pilocarpine rat model of TLE. Furthermore, ROCK2 activated the Stat3 pathway in pilocarpine-treated epilepsy rats, and the spearman correlation method confirmed that ROCK2 is associated with Stat3 activation in TLE patients. In addition, ROCK2 was predominantly expressed in astrocytes during epileptogenesis, and induced epileptogenesis by activating astrocyte cell cycle progression via Stat3 pathway. The overexpressed ROCK2 plays an important role in the pathogenesis of drug-resistant epilepsy. ROCK2 accelerates astrocytes cell cycle progression via the activation of Stat3 pathway likely provides the key to explaining the process of epileptogenesis.

Circumventing Drug Resistance Pathways with a Nanoparticle-Based Photodynamic Method.

Drug resistance remains the dominant impediment for cancer therapy, not only because compensatory drug resistance pathways are always activated, but also because of the cross-resistance of cancer cells to unrelated therapeutics. Herein, chemodrug-sensitive cancer cells, intrinsic drug-resistant cells, and acquired resistant cells were employed to uncover their biological response to a nanoparticle-based photodynamic method in tumoral, cellular, and molecular levels. We observed that nanoparticle-based photodynamic process with high therapeutic efficiency, intracellular delivery, and tumor penetration effect resulted in the indiscriminate and significant therapeutic outcome, in contrast to the diversiform effect of first-line chemo-drug, Temozolomide (TMZ). By real-time quantitative PCR array technique, we revealed that signals in classical resistance pathways were unaffected or downregulated, and photodynamic effect initiates cell apoptosis via downstream genes. The discovery that nanoparticulate photodynamic therapy bypasses the signals in multiple resistant pathways may imply an alternative route for combating drug resistance of cancer.

Bacterial minicells to the rescue: cyto-Immunotherapy for the treatment of late stage cancers with minimal to no toxicity.

Bacterial minicells to the rescue: cyto-Immunotherapy for the treatment of late stage cancers with minimal to no toxicity.

Targeting Glioblastoma: The Current State of Different Therapeutic Approaches.

BackgroundGlioma is the primary cancer of the central nervous system in adults. Among gliomas, glioblastoma is the most deadly and aggressive form, with an average life span of 1 to 2 years. Despite implementing the rigorous standard care involving maximal surgical removal followed by concomitant radiation and chemotherapy, the patient prognosis remains poor. Due to the infiltrative nature of glioblastoma, chemo- and radio-resistance behavior of these tumors and lack of potent chemotherapeutic drugs, treatment of glioblastoma is still a big challenge.ObjectiveThe goal of the present review is to shed some light on the present state of novel strategies, including molecular therapies, immunotherapies, nanotechnology and combination therapies for patients with glioblastoma.MethodsPeer-reviewed literature was retrieved via Embase, Ovid, PubMed and Google Scholar till the year 2020.ConclusionInsufficient effect of chemotherapies for glioblastoma is more likely because of different drug resistance mechanisms and intrinsically complex pathological characteristics. Therefore, more advancement in various therapeutic approaches such as antitumor immune response, targeting growth regulatory and drug resistance pathways, enhancing drug delivery and drug carrier systems are required in order to establish an effective treatment approach for patients with glioblastoma.

Short Communication: Update in Natural Antiretroviral Resistance-Associated Mutations Among HIV Type 2 Variants and Discrepancies Across HIV Type 2 Resistance Interpretation Tools.

HIV variants carry natural polymorphisms related to drug resistance (R-markers) fixed during viral evolution in the absence of antiretroviral therapy (ART) that may impact on drug susceptibility and resistance pathways. We aimed to identify the HIV type 2 (HIV-2) variant-specific R-markers at Pol in all available sequences from ART-naive subjects deposited in Los Alamos database according to reported HIV-2 drug resistance-associated mutations (DRMs) and report the performance of two online HIV-2 resistance interpretation tools (HIV2EU Tool and Stanford HIVdb Program for HIV-2) to detect them. From a total of 587 sequences, we found 23 R-markers in low frequency, in groups A, B, and G. Four were present in >10% of the sequences with no direct impact on antiretroviral susceptibility. HIV2EU Tool detected one, whereas Stanford program all four. Stanford new tool, although still under development, seems effective in detecting HIV-2 DRMs and may prove a useful tool for HIV-2 resistance interpretation when fully developed.

The Candida glabrata Upc2A transcription factor is a global regulator of antifungal drug resistance pathways.

The most commonly used antifungal drugs are the azole compounds, which interfere with biosynthesis of the fungal-specific sterol: ergosterol. The pathogenic yeast Candida glabrata commonly acquires resistance to azole drugs like fluconazole via mutations in a gene encoding a transcription factor called PDR1. These PDR1 mutations lead to overproduction of drug transporter proteins like the ATP-binding cassette transporter Cdr1. In other Candida species, mutant forms of a transcription factor called Upc2 are associated with azole resistance, owing to the important role of this protein in control of expression of genes encoding enzymes involved in the ergosterol biosynthetic pathway. Recently, the C. glabrata Upc2A factor was demonstrated to be required for normal azole resistance, even in the presence of a hyperactive mutant form of PDR1. Using genome-scale approaches, we define the network of genes bound and regulated by Upc2A. By analogy to a previously described hyperactive UPC2 mutation found in Saccharomyces cerevisiae, we generated a similar form of Upc2A in C. glabrata called G898D Upc2A. Analysis of Upc2A genomic binding sites demonstrated that wild-type Upc2A binding to target genes was strongly induced by fluconazole while G898D Upc2A bound similarly, irrespective of drug treatment. Transcriptomic analyses revealed that, in addition to the well-described ERG genes, a large group of genes encoding components of the translational apparatus along with membrane proteins were responsive to Upc2A. These Upc2A-regulated membrane protein-encoding genes are often targets of the Pdr1 transcription factor, demonstrating the high degree of overlap between these two regulatory networks. Finally, we provide evidence that Upc2A impacts the Pdr1-Cdr1 system and also modulates resistance to caspofungin. These studies provide a new perspective of Upc2A as a master regulator of lipid and membrane protein biosynthesis.

The baseline oral microbiota predicts the response of locally advanced oral squamous cell carcinoma patients to induction chemotherapy: A prospective longitudinal study

PurposeAmong oral squamous cell carcinoma (OSCC) patients who receive docetaxel, cisplatin, and 5-fluorouracil (TPF) induction chemotherapy, those with a favorable pathological response tend to obtain satisfactory clinical outcomes, while the total population exhibit no survival benefit. Thus, there is an urgent need to improve the therapeutic effect of TPF by applying personalized treatment according to distinct biomarkers. Methods and materialsIn the present study, we collected oral rinse samples from 44 OSCC patients enrolled in our prospective multicenter random phase II trial before TPF induction chemotherapy to conduct 16S rRNA gene sequencing and metagenomic analysis. Patients were administrated with two cycles of TPF induction chemotherapy (75 mg/m2 cisplatin and 75 mg/m2 docetaxel on day 1 and 750 mg/m2 fluorouracil from the first to the fifth day), and then divided into responsive and nonresponsive groups according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. ResultsIn the 16S rRNA gene sequence analysis, Fusobacterium and Mycoplasma were more enriched in the nonresponsive group, while Slackia was more enriched in the responder group at the genus level. In the metagenomic shotgun sequencing analysis, Fusobacterium nucleatum was more enriched in the nonresponsive group. Functional analysis showed that the platinum drug resistance pathway and microRNAs in cancer and RNA degradation pathways were remarkably associated with patient sensitivity to induction chemotherapy. ConclusionsOur data suggest that the oral microbiome may play an important role in the OSCC patient sensitivity to TPF induction chemotherapy and offer novel potential biomarkers for predicting the response to TPF induction chemotherapy.

Cation-Free siRNA Micelles as Effective Drug Delivery Platform and Potent RNAi Nanomedicines for Glioblastoma Therapy.

Nanoparticle-based small interfering RNA (siRNA) therapy shows great promise for glioblastoma (GBM). However, charge associated toxicity and limited blood-brain-barrier (BBB) penetration remain significant challenges for siRNA delivery for GBM therapy. Herein, novel cation-free siRNA micelles, prepared by the self-assembly of siRNA-disulfide-poly(N-isopropylacrylamide) (siRNA-SS-PNIPAM) diblock copolymers, are prepared. The siRNA micelles not only display enhanced blood circulation time, superior cell take-up, and effective at-site siRNA release, but also achieve potent BBB penetration. Moreover, due to being non-cationic, these siRNA micelles exert no charge-associated toxicity. Notably, these desirable properties of this novel RNA interfering (RNAi) nanomedicine result in outstanding growth inhibition of orthotopic U87MG xenografts without causing adverse effects, achieving remarkably improved survival benefits. Moreover, as a novel type of polymeric micelle, the siRNA micelle displays effective drug loading ability. When utilizing temozolomide (TMZ) as a model loading drug, the siRNA micelle realizes effective synergistic therapy effect via targeting the key gene (signal transducers and activators of transcription 3, STAT3) in TMZ drug resistant pathways. The authors' results show that this siRNA micelle nanoparticle can serve as a robust and versatile drug codelivery platform, and RNAi nanomedicine and for effective GBM treatment.

Epigenetic Alterations and Mechanisms That Drive Resistance to Targeted Cancer Therapies.

Cancer is a complex disease and cancer cells typically harbor multiple genetic and epigenetic alterations. Large-scale sequencing of patient-derived cancer samples has identified several druggable driver oncogenes. Many of these oncogenes can be pharmacologically targeted to provide effective therapies for breast cancer, leukemia, lung cancer, melanoma, lymphoma, and other cancer types. Initial responses to these agents can be robust in many cancer types and some patients with cancer experience sustained tumor inhibition. However, resistance to these targeted therapeutics frequently emerges, either from intrinsic or acquired mechanisms, posing a major clinical hurdle for effective treatment. Several resistance mechanisms, both cell autonomous and cell nonautonomous, have been identified in different cancer types. Here we describe how alterations of the transcriptome, transcription factors, DNA, and chromatin regulatory proteins confer resistance to targeted therapeutic agents. We also elaborate on how these studies have identified underlying epigenetic factors that drive drug resistance and oncogenic pathways, with direct implications for the prevention and treatment of drug-resistant cancer.

The Pathogenic Role of PI3K/AKT Pathway in Cancer Onset and Drug Resistance: An Updated Review.

Simple SummaryDrug resistance remains one of the major problems in cancer therapy and is responsible for up to 90% of cancer-related deaths. It exists across all types of cancer and treatment; thus, determining how to overcome this problem is a goal that involves understanding biological mechanisms and also includes clinical trials to test new therapeutic strategies. In this review, we will highlight the emerging role of the PI3K/Akt pathway in drug resistance by discussing recent findings of a multi-level deregulation. Combinational and personalized therapies, which should take this pathway into consideration, might provide better treatment strategies and improved efficacy for fighting drug resistance in cancer.The PI3K/AKT pathway is one of the most frequently over-activated intracellular pathways in several human cancers. This pathway, acting on different downstream target proteins, contributes to the carcinogenesis, proliferation, invasion, and metastasis of tumour cells. A multi-level impairment, involving mutation and genetic alteration, aberrant regulation of miRNAs sequences, and abnormal phosphorylation of cascade factors, has been found in multiple cancer types. The deregulation of this pathway counteracts common therapeutic strategies and contributes to multidrug resistance. In this review, we underline the involvement of this pathway in patho-physiological cell survival mechanisms, emphasizing its key role in the development of drug resistance. We also provide an overview of the potential inhibition strategies currently available.

The Landscape of Genetic Alterations Stratified Prognosis in Oriental Pancreatic Cancer Patients.

BackgroundPancreatic cancer is a life-threatening malignant disease with significant diversity among geographic regions and races leading to distinct carcinogenesis and prognosis. Previous studies mainly focused on Western patients, while the genomic landscape of Oriental patients, especially Chinese, remained less investigated.MethodsA total of 408 pancreatic cancer patients were enrolled. A panel containing 436 cancer-related genes was used to detect genetic alterations in tumor samples.ResultsWe profiled the genomic alteration landscape of pancreatic duct adenocarcinoma (PDAC), intraductal papillary mucinous neoplasm (IPMN), periampullary carcinoma (PVC), and solid-pseudopapillary tumor (SPT). Comparison with a public database revealed specific gene mutations in Oriental PDAC patients including higher mutation rates of DNA damage repair-related genes. Analysis of mutational signatures showed potential heterogenous carcinogenic factors caused by diabetes mellitus. KRAS mutation, especially KRAS G12D mutation, was associated with poor survival, while patients not harboring the 17 significant copy number variations (CNVs) had a better prognosis. We further identified multiple correlations between clinicopathologic variables and genetic mutations, as well as CNVs. Finally, by network-based stratification, three classes of PDAC patients were robustly clustered. Among these, class 1 (characterized by the Fanconi anemia pathway) achieved the best outcome, while class 2 (involved in the platinum drug resistance pathway) suffered from the worst prognosis.ConclusionsIn this study, we reported for the first time the genetic alteration landscape of Oriental PDAC patients identifying many Oriental-specific alterations. The relationship between genetic alterations and clinicopathological factors as well as prognosis demonstrated important genomic impact on tumor biology. This study will help to optimize clinical treatment of Oriental PDAC patients and improve their survival.