Overcoming acquired resistance to anticancer therapy: focus on the PI3K/AKT/mTOR pathway

Hallmarks of cancer resistance

This review explores the hallmarks of cancer resistance, including drug efflux mediated by ATP-binding cassette (ABC) transporters, metabolic reprogramming characterized by the Warburg effect, and the dynamic interplay between cancer cells and mitochondria. The role of cancer stem cells (CSCs) in treatment resistance and the regulatory influence of non-coding RNAs, such as long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are studied. The chapter emphasizes future directions, encompassing advancements in immunotherapy, strategies to counter adaptive resistance, integration of artificial intelligence for predictive modeling, and the identification of biomarkers for personalized treatment. The comprehensive exploration of these hallmarks provides a foundation for innovative therapeutic approaches, aiming to navigate the complex landscape of cancer resistance and enhance patient outcomes.

An updated review of the pharmacological effects and potential mechanisms of hederagenin and its derivatives

Hederagenin (HG) is a natural pentacyclic triterpenoid that can be isolated from various medicinal herbs. By modifying the structure of HG, multiple derivatives with superior biological activities and safety profiles have been designed and synthesized. Accumulating evidence has demonstrated that HG and its derivatives display multiple pharmacological activities against cancers, inflammatory diseases, infectious diseases, metabolic diseases, fibrotic diseases, cerebrovascular and neurodegenerative diseases, and depression. Previous studies have confirmed that HG and its derivatives combat cancer by exerting cytotoxicity, inhibiting proliferation, inducing apoptosis, modulating autophagy, and reversing chemotherapy resistance in cancer cells, and the action targets involved mainly include STAT3, Aurora B, KIF7, PI3K/AKT, NF-κB, Nrf2/ARE, Drp1, and P-gp. In addition, HG and its derivatives antagonize inflammation through inhibiting the production and release of pro-inflammatory cytokines and inflammatory mediators by regulating inflammation-related pathways and targets, such as NF-κB, MAPK, JAK2/STAT3, Keap1-Nrf2/HO-1, and LncRNA A33/Axin2/β-catenin. Moreover, anti-pathogen, anti-metabolic disorder, anti-fibrosis, neuroprotection, and anti-depression mechanisms of HG and its derivatives have been partially elucidated. The diverse pharmacological properties of HG and its derivatives hold significant implications for future research and development of new drugs derived from HG, which can lead to improved effectiveness and safety profiles.

Targeting PI3K/AKT/mTOR signaling to overcome drug resistance in cancer

This review comprehensively explores the challenge of drug resistance in cancer by focusing on the pivotal PI3K/AKT/mTOR pathway, elucidating its role in oncogenesis and resistance mechanisms across various cancer types. It meticulously examines the diverse mechanisms underlying resistance, including genetic mutations, feedback loops, and microenvironmental factors, while also discussing the associated resistance patterns. Evaluating current therapeutic strategies targeting this pathway, the article highlights the hurdles encountered in drug development and clinical trials. Innovative approaches to overcome resistance, such as combination therapies and precision medicine, are critically analyzed, alongside discussions on emerging therapies like immunotherapy and molecularly targeted agents. Overall, this comprehensive review not only sheds light on the complexities of resistance in cancer but also provides a roadmap for advancing cancer treatment.

ABCG2 Mediates Resistance to the Dual EGFR and PI3K Inhibitor MTX-211 in Cancer Cells

MTX-211 is a first-in-class dual inhibitor of epidermal growth factor receptor (EGFR) and phosphoinositide-3 kinase (PI3K) signaling pathways with a compelling pharmaceutical profile and could enhance the effectiveness of mitogen-activated protein kinase kinase (MEK) inhibitor therapy in colorectal tumors with KRAS mutations. However, the specific mechanisms contributing to the acquired resistance to MTX-211 in human cancers remain elusive. Here, we discovered that the overexpression of the ATP-binding cassette (ABC) drug transporter ABCG2, a prevalent mechanism associated with multidrug resistance (MDR), could diminish the effectiveness of MTX-211 in human cancer cells. We showed that the drug efflux activity of ABCG2 substantially decreased the intracellular accumulation of MTX-211 in cancer cells. As a result, the cytotoxicity and effectiveness of MTX-211 in suppressing the activation of the EGFR and PI3K pathways were significantly attenuated in cancer cells overexpressing ABCG2. Moreover, the enhancement of the MTX-211-stimulated ATPase activity of ABCG2 and the computational molecular docking analysis illustrating the binding of MTX-211 to the substrate-binding sites of ABCG2 offered a further indication for the interaction between MTX-211 and ABCG2. In summary, our findings indicate that MTX-211 acts as a substrate for ABCG2, underscoring the involvement of ABCG2 in the emergence of resistance to MTX-211. This finding carries clinical implications and merits further exploration.

A Phase Ib Expansion Cohort Evaluating Aurora A Kinase Inhibitor Alisertib and Dual TORC1/2 Inhibitor Sapanisertib in Patients with Advanced Solid Tumors

BACKGROUND

This study further evaluated the safety and efficacy of the combination of alisertib and sapanisertib in an expansion cohort of patients, including a subset of patients with refractory pancreatic adenocarcinoma, with further evaluation of the pharmacodynamic characteristics of combination therapy.

METHODS

Twenty patients with refractory solid tumors and 11 patients with pancreatic adenocarcinoma were treated at the recommended phase 2 dose of alisertib and sapanisertib. Adverse events and disease response were assessed. Patients in the expansion cohort were treated with a 7-day lead-in of either alisertib or sapanisertib prior to combination therapy, with tumor tissue biopsy and serial functional imaging performed for correlative analysis.

RESULTS

Toxicity across treatment groups was overall similar to prior studies. One partial response to treatment was observed in a patient with ER positive breast cancer, and a patient with pancreatic cancer experienced prolonged stable disease. In an additional cohort of pancreatic cancer patients, treatment response was modest. Correlative analysis revealed variability in markers of apoptosis and immune cell infiltrate according to lead-in therapy and response.

CONCLUSIONS

Dual targeting of Aurora A kinase and mTOR resulted in marginal clinical benefit in a population of patients with refractory solid tumors, including pancreatic adenocarcinoma, though individual patients experienced significant response to therapy. Correlatives indicate apoptotic response and tumor immune cell infiltrate may affect clinical outcomes.

Transcriptome analysis of an AKT inhibitor-resistant endometrial cancer cell line

BACKGROUND

Drug resistance in endometrial cancer (EC) is a serious problem and a barrier to improving prognosis. The PI3K/AKT/mTOR pathway is highly activated in EC and can serve as a potential therapeutic target. Inhibitors against AKT have been developed, but resistance to these inhibitors is a concern. This study aimed to establish AKT inhibitor resistant cell lines and identify differentially expressed genes (DEGs) between parental and AKT inhibitor resistant cell lines to understand the mechanism of drug resistance to AKT inhibitors in EC.

METHODS

The sensitivity of eight EC cell lines to AKT inhibitor was analyzed. One of them was used to establish a drug-resistant cell line. DEGs were examined using RNA sequencing (RNA-seq). Furthermore, DEGs were comprehensively analyzed to identify hub genes. Hub genes were evaluated using quantitative real-time polymerase chain reaction.

RESULTS

RNA-seq identified 617 DEGs. Hub genes were selected using bioinformatics analysis. The top 10 hub genes were TNF, CDH1, CCND1, COL1A1, CDH2, ICAM1, CAV1, THBS1, NCAM1, and CDKN2A. Relative mRNA expression was significantly upregulated for TNF, CDH1, CCND1, THBS1, p16INK4a, and p14ARF and significantly downregulated for CDH2, ICAM1, and NCAM1 in borussertib-resistant EC cell line.

CONCLUSIONS

Drug resistance to AKT inhibitors may depend on genes related to cell adhesion-mediated resistance and transforming growth factor β signaling.

Genetic loss of Nrf1 and Nrf2 leads to distinct metabolism reprogramming of HepG2 cells by opposing regulation of the PI3K-AKT-mTOR signalling pathway

As a vital hallmarker of cancer, the metabolic reprogramming has been shown to play a pivotal role in tumour occurrence, metastasis and drug resistance. Amongst a vast variety of signalling molecules and metabolic enzymes involved in the regulation of cancer metabolism, two key transcription factors Nrf1 and Nrf2 are required for redox signal transduction and metabolic homeostasis. However, the regulatory effects of Nrf1 and Nrf2 (both encoded by Nfe2l1 and Nfe2l2, respectively) on the metabolic reprogramming of hepatocellular carcinoma cells have been not well understood to date. Here, we found that the genetic deletion of Nrf1 and Nrf2 from HepG2 cells resulted in distinct metabolic reprogramming. Loss of Nrf1α led to enhanced glycolysis, reduced mitochondrial oxygen consumption, enhanced gluconeogenesis and activation of the pentose phosphate pathway in the hepatocellular carcinoma cells. By striking contrast, loss of Nrf2 attenuated the glycolysis and gluconeogenesis pathways, but with not any significant effects on the pentose phosphate pathway. Moreover, knockout of Nrf1α also caused fat deposition and increased amino acid synthesis and transport, especially serine synthesis, whilst Nrf2 deficiency did not cause fat deposition, but attenuated amino acid synthesis and transport. Further experiments revealed that such distinctive metabolic programming of between Nrf1α-/- and Nrf2-/- resulted from substantial activation of the PI3K-AKT-mTOR signalling pathway upon the loss of Nrf1, leading to increased expression of critical genes for the glucose uptake, glycolysis, the pentose phosphate pathway, and the de novo lipid synthesis, whereas deficiency of Nrf2 resulted in the opposite phenomenon by inhibiting the PI3K-AKT-mTOR pathway. Altogether, these provide a novel insight into the cancer metabolic reprogramming and guide the exploration of a new strategy for targeted cancer therapy.

Mutant PIK3CA as a negative predictive biomarker for treatment with a highly selective PIM1 inhibitor in human colon cancer

Significant improvement in targeted therapy for colorectal cancer (CRC) has occurred over the past few decades since the approval of the EGFR inhibitor cetuximab. However, cetuximab is used only for patients possessing the wild-type oncogene KRAS, NRAS, and BRAF, and even most of these eventually acquire therapeutic resistance, via activation of parallel oncogenic pathways such as RAS-MAPK or PI3K/Akt/mTOR. The two aforementioned pathways also contribute to the development of therapeutic resistance in CRC patients, due to compensatory and feedback mechanisms. Therefore, combination drug therapies (versus monotherapy) targeting these multiple pathways may be necessary for further efficacy against CRC. In this study, we identified PIK3CA mutant (PIK3CA MT) as a determinant of resistance to SMI-4a, a highly selective PIM1 kinase inhibitor, in CRC cell lines. In CRC cell lines, SMI-4a showed its effect only in PIK3CA wild type (PIK3CA WT) cell lines, while PIK3CA MT cells did not respond to SMI-4a in cell death assays. In vivo xenograft and PDX experiments confirmed that PIK3CA MT is responsible for the resistance to SMI-4a. Inhibition of PIK3CA MT by PI3K inhibitors restored SMI-4a sensitivity in PIK3CA MT CRC cell lines. Taken together, these results demonstrate that sensitivity to SMI-4a is determined by the PIK3CA genotype and that co-targeting of PI3K and PIM1 in PIK3CA MT CRC patients could be a promising and novel therapeutic approach for refractory CRC patients.

Gut microbiota and immunotherapy of renal cell carcinoma

The gut microbiome has recently been proposed as a key player in cancer development and progression. Several studies have reported that the composition of the gut microbiome plays a role in the response to immune checkpoint inhibitors (ICIs). The gut microbiome modulation has been investigated as a potential therapeutic strategy for cancer, mainly in patients undergoing therapy with ICIs. In particular, modulation through probiotics, FMT or other microbiome-related approaches have proven effective to improve the response to ICIs. In this review, we examine the role of the gut microbiome in enhancing clinical responses to ICIs in the treatment of renal cancer.

New Thiazolyl-Pyrazoline Derivatives as Potential Dual EGFR/HER2 Inhibitors: Design, Synthesis, Anticancer Activity Evaluation and In Silico Study

A new series of thiazolyl-pyrazoline derivatives (4a-d, 5a-d 6a, b, 7a-d, 8a, b, and 10a, b) have been designed and synthesized through the combination of thiazole and pyrazoline moieties, starting from the key building blocks pyrazoline carbothioamides (1a-b). These eighteen derivatives have been designed as anticipated EGFR/HER2 dual inhibitors. The efficacy of the developed compounds in inhibiting cell proliferation was assessed using the breast cancer MCF-7 cell line. Among the new synthesized thiazolyl-pyrazolines, compounds 6a, 6b, 10a, and 10b displayed potent anticancer activity toward MCF-7 with IC50 = 4.08, 5.64, 3.37, and 3.54 µM, respectively, when compared with lapatinib (IC50 = 5.88 µM). In addition, enzymatic assays were also run for the most cytotoxic compounds (6a and 6b) toward EGFR and HER2 to demonstrate their dual inhibitory activity. They revealed promising inhibition potency against EGFR with IC50 = 0.024, and 0.005 µM, respectively, whereas their IC50 = 0.047 and 0.022 µM toward HER2, respectively, compared with lapatinib (IC50 = 0.007 and 0.018 µM). Both compounds 6a and 10a induced apoptosis by arresting the cell cycle of the MCF-7 cell line at the G1 and G1/S phases, respectively. Molecular modeling studies for the promising candidates 6a and 10a showed that they formed the essential binding with the crucial amino acids for EGFR and HER2 inhibition, supporting the in vitro assay results. Furthermore, ADMET study predictions were carried out for the compounds in the study.

Prognostic impact of molecular profiles and molecular signatures in clear cell ovarian cancer

OBJECTIVE

Ovarian Clear cell carcinomas (OCCC) are characterized by low response to chemotherapy and a poor prognosis in advanced stages. Several studies have demonstrated that OCCC are heterogenous entities. We have earlier identified four molecular profiles based on the mutational status of ARID1A and PIK3CA. In this study we aimed to examine the association between molecular profiles, Tumor Mutational Burden (TMB), and molecular signatures with the clinical outcome in OCCC METHODS: We identified 55 OCCC cases with corresponding data and biological tissue samples in the Danish Gynecological Cancer Database during 2005-2016. Mutational profiling and TMB were performed using the Oncomine Tumor Mutational Load Assay. Chi-square and Cox regression analyses were used. P-values < 0.05 were considered statistically significant.

RESULTS

Mutations in the PIK3CA gene (p=0.04) and low TMB (p=0.05) were associated with disease progression. In multivariate analyses adjusted for stage, patients with tumor mutations in the ARID1A and/or PIK3CA genes had a significantly impaired Progression Free Survival (PFS) and Overall Survival (OS) compared to patients who were wildtype ARID1A and PIK3CA (undetermined subgroup) (HR= 5.42 and HR= 2.77, respectively). High TMB status was associated with an improved PFS (HR= 0.36) and OS (HR= 0.46). A trend towards an improved PFS in patients with APOBEC enrichment was observed (HR 0.45).

CONCLUSION

TMB-High was associated with decreased risk of progression and with an improved PFS and OS. Furthermore, OCCC with mutations in either ARID1A and/or PIK3CA genes had a significantly impaired prognosis compared to the undetermined subgroup in stage adjusted analyses.

Model-based prediction of effective target exposure for MEN1611 in combination with trastuzumab in HER2-positive advanced or metastatic breast cancer patients

MEN1611 is a novel orally bioavailable PI3K inhibitor currently in clinical development for patients with HER2-positive (HER2+) PI3KCA mutated advanced/metastatic breast cancer (BC) in combination with trastuzumab (TZB). In this work, a translational model-based approach to determine the minimum target exposure of MEN1611 in combination with TZB was applied. First, pharmacokinetic (PK) models for MEN1611 and TZB in mice were developed. Then, in vivo tumor growth inhibition (TGI) data from seven combination studies in mice xenograft models representative of the human HER2+ BC non-responsive to TZB (alterations of the PI3K/AkT/mTOR pathway) were analyzed using a PK-pharmacodynamic (PD) TGI model for co-administration of MEN1611 and TZB. The established PK-PD relationship was used to quantify the minimum effective MEN1611 concentration, as a function of TZB concentration, needed for tumor eradication in xenograft mice. Finally, a range of minimum effective exposures for MEN1611 were extrapolated to patients with BC, considering the typical steady-state TZB plasma levels in patients with BC following three alternative regimens (i.v. 4 mg/kg loading dose +2 mg/kg q1w, i.v. 8 mg/kg loading dose +6 mg/kg q3w or s.c. 600 mg q3w). A threshold of about 2000 ng·h/ml for MEN1611 exposure associated with a high likelihood of effective antitumor activity in a large majority of patients was identified for the 3-weekly and the weekly i.v. schedule for TZB. A slightly lower exposure (i.e., 25% lower) was found for the 3-weekly s.c. schedule. This important outcome confirmed the adequacy of the therapeutic dose administered in the ongoing phase 1b B-PRECISE-01 study in patients with HER2+ PI3KCA mutated advanced/metastatic BC.

From signalling pathways to targeted therapies: unravelling glioblastoma's secrets and harnessing two decades of progress

Glioblastoma, a rare, and highly lethal form of brain cancer, poses significant challenges in terms of therapeutic resistance, and poor survival rates for both adult and paediatric patients alike. Despite advancements in brain cancer research driven by a technological revolution, translating our understanding of glioblastoma pathogenesis into improved clinical outcomes remains a critical unmet need. This review emphasises the intricate role of receptor tyrosine kinase signalling pathways, epigenetic mechanisms, and metabolic functions in glioblastoma tumourigenesis and therapeutic resistance. We also discuss the extensive efforts over the past two decades that have explored targeted therapies against these pathways. Emerging therapeutic approaches, such as antibody-toxin conjugates or CAR T cell therapies, offer potential by specifically targeting proteins on the glioblastoma cell surface. Combination strategies incorporating protein-targeted therapy and immune-based therapies demonstrate great promise for future clinical research. Moreover, gaining insights into the role of cell-of-origin in glioblastoma treatment response holds the potential to advance precision medicine approaches. Addressing these challenges is crucial to improving outcomes for glioblastoma patients and moving towards more effective precision therapies.

NQO1 drives glioblastoma cell aggressiveness through EMT induction via the PI3K/Akt/mTOR/Snail pathway

Glioblastoma multiforme (GBM) is the most frequent and lethal cancer derived from the central nervous system, of which the mesenchymal (MES) subtype seriously influences the survival and prognosis of patients. NAD(P)H: quinone acceptor oxidoreductase 1 (NQO1) serves an important role in the carcinogenesis and progression of various types of cancer; however, the specific mechanism underlying the regulatory effects of NQO1 on GBM is unclear. Thus, the present study aimed to explore the role and mechanism of NQO1 in GBM progression. The results of bioinformatics analysis and immunohistochemistry showed that high expression of NQO1 was significantly related to the MES phenotype of GBM and shorter survival. In addition, MTT, colony formation, immunofluorescence and western blot analyses, and lung metastasis model experiments suggested that silencing NQO1 inhibited the proliferation and metastasis of GBM cells in vitro and in vivo. Furthermore, western blotting showed that the activity of the PI3K/Akt/mTOR signaling pathway was revealed to be inhibited by downregulation of NQO1 expression, whereas it was enhanced by overexpression of NQO1. Notably, co‑immunoprecipitation and ubiquitination experiments suggested that Snail was considered an important downstream target of NQO1 in GBM cells. Snail knockdown could eliminate the promoting effect of ectopic NQO1 on the proliferation and invasion of GBM cells, and reduce its effects on the activity of PI3K/Akt/mTOR signaling pathway. These results indicated that NQO1 could promote GBM aggressiveness by activating the PI3K/Akt/mTOR signaling pathway in a Snail‑dependent manner, and NQO1 and its relevant pathways may be considered novel targets for GBM therapy.

Antiproliferative effect of Potentilla fulgens on glioblastoma cancer cells through downregulation of Akt/mTOR signaling pathway

BACKGROUND

Glioblastoma multiforme (GBM) is the most aggressive brain tumor that is common among adults. This aggression is due to increased invasion, migration, proliferation, angiogenesis, and decreased apoptosis. Plant-based compounds have a high potential to be used as an anticancer agent due to their various mechanisms and less undesirable side effects. Potentilla fulgens is a medicinal plant, and methanolic root extract of P. fulgens (PRE) has anti-inflammatory and anticancer properties.

OBJECTIVE

In this study, we aimed to investigate antiproliferative effect of PRE on U118 and T98G glioblastoma cancer cells and to reveal which molecular signaling pathways regulate this mechanism of action.

MATERIALS AND METHODS

The effect of PRE on cell viability of GBM cells was investigated by MTT assay. Involvement of PRE with cell growth and survival signaling pathways, phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR and c-Src/signal transducer and activator of transcription 3 (STAT3), was examined using Western Blot.

RESULTS

PRE reduced cell viability of GBM and human dermal fibroblast (HDF) cells in a dose-and time-independent manner. PI3K expression/phosphorylation level remained unchanged in both GBM and HDF cells after PRE treatment, but Akt/mTOR signaling pathway was downregulated in PRE-treated cells. PRE treatment did not affect c-Src expression/phosphorylation level in GBM cells; however, expression of c-Src was suppressed in HDF cells. Similar results were observed for STAT3 expression and phosphorylation status.

CONCLUSION

PRE has the ability to suppress cell viability in GBM cells, by targeting the Akt/mTOR signaling pathway.

Resistance to hormone therapy in breast cancer cells promotes autophagy and EGFR signaling pathway

Breast cancer is the leading cause of cancer deaths for women worldwide. Endocrine therapies represent the cornerstone for hormone-dependent breast cancer treatment. However, in many cases, endocrine resistance is induced with poor prognosis for patients. In the current study, we have developed MCF-7 cell lines resistant to fulvestrant (MCF-7Fulv) and tamoxifen (MCF-7Tam) aiming at investigating mechanisms underlying resistance. Both resistant cell lines exerted lower proliferation capacity in two-dimensional (2-D) cultures but retain estrogen receptor α (ERα) expression and proliferate independent of the presence of estrogens. The established cell lines tend to be more aggressive exhibiting advanced capacity to form colonies, increased expression of epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and heterodimerization of ERBB family receptors and activation of EGFR downstream pathways like MEK/ERK1/2 and PI3K/AKT. Tyrosine kinase inhibitors tested against resistant MCF-7Fulv and MCF-7Tam cells showed moderate efficacy to inhibit cell proliferation, except for lapatinib, which concomitantly inhibits both EGFR and HER2 receptors and strongly reduced cell proliferation. Furthermore, increased autophagy was observed in resistant MCF-7Fulv and MCF-7Tam cells as shown by the presence of autophagosomes and increased Beclin-1 levels. The increased autophagy in resistant cells is not associated with increased apoptosis, suggesting a cytoprotective role for autophagy that may favor cells' survival and aggressiveness. Thus, by exploiting those underlying mechanisms, new targets could be established to overcome endocrine resistance.NEW & NOTEWORTHY The development of resistance to hormone therapy caused by both fulvestrant and tamoxifen promotes autophagy with concomitant apoptosis evasion, rendering cells capable of surviving and growing. The fact that resistance also triggers ERBB family signaling pathways, which are poorly inhibited by tyrosine kinase inhibitors might attribute to cells' aggressiveness. It is obvious that the development of endocrine therapy resistance involves a complex interplay between deregulated ERBB signaling and autophagy that may be considered in clinical practice.

miRNome expression analysis in canine diffuse large B-cell lymphoma

Introduction

Lymphoma is a common canine cancer with translational relevance to human disease. Diffuse large B-cell lymphoma (DLBCL) is the most frequent subtype, contributing to almost fifty percent of clinically recognized lymphoma cases. Identifying new biomarkers capable of early diagnosis and monitoring DLBCL is crucial for enhancing remission rates. This research seeks to advance our knowledge of the molecular biology of DLBCL by analyzing the expression of microRNAs, which regulate gene expression by negatively impacting gene expression via targeted RNA degradation or translational repression. The stability and accessibility of microRNAs make them appropriate biomarkers for the diagnosis, prognosis, and monitoring of diseases.

Methods

We extracted and sequenced microRNAs from ten fresh-frozen lymph node tissue samples (six DLBCL and four non-neoplastic).

Results

Small RNA sequencing data analysis revealed 35 differently expressed miRNAs (DEMs) compared to controls. RT-qPCR confirmed that 23/35 DEMs in DLBCL were significantly upregulated (n = 14) or downregulated (n = 9). Statistical significance was determined by comparing each miRNA's average expression fold-change (2-Cq) between the DLCBL and healthy groups by applying the unpaired parametric Welch's 2-sample t-test and false discovery rate (FDR). The predicted target genes of the DEMs were mainly enriched in the PI3K-Akt-MAPK pathway.

Discussion

Our data point to the potential value of miRNA signatures as diagnostic biomarkers and serve as a guideline for subsequent experimental studies to determine the targets and functions of these altered miRNAs in canine DLBCL.

Genomic signatures and prognosis of advanced stage Chinese pediatric T cell lymphoblastic lymphoma by whole exome sequencing

Objective

To investigate the genomic signatures and prognosis of advanced-stage T cell lymphoblastic lymphoma (T-LBL) and to examine the relationship between T-LBL and T cell acute lymphoblastic leukemia (T-ALL).

Methods

35 Chinese T-LBL children with stage III or IV disease were recruited for this study. They were treated with combination chemotherapy and whole exome sequencing. The relationship of the clinical features, prognosis and specific gene mutations was researched. Gene chips of T-LBL and T-ALL were downloaded from a database, and differential gene expression was analyzed.

Results

Germline causal gene mutations (CARS or MAP2K2) were detected in 2 patients; 3.06 ± 2.21 somatic causal gene mutations were identified in the 35 patients, and somatic mutations were observed in the NOTCH1, FBXW7, PHF6 and JAK3 genes. NOTCH1 mutations were significantly associated with FBXW7 mutations, and the age at diagnosis of patients with NOTCH1-FBXW7 mutations was less than that of patients without such mutations (P < 0.05). 32 patients achieved complete remission (CR), and 14 and 18 patients were classified into the intermediate risk (IR) group and high risk (HR) group. During a median follow-up of 44 months, 3 patients relapsed. Three-year prospective event free survival (pEFS) was 82.286%, and no significant differences of pEFS were found for different sexes, ages, or statuses of NOTCH1-FBXW7 mutations, (P > 0.05); however, the mean survival time of the IR group was longer than that of the HR group (P < 0.05). Differential expression of genes in the T-LBL and/or T-ALL datasets was analyzed using the R package limma, and 1/3 of the differentially expressed genes were found in both the T-ALL and T-LBL datasets. High expression of PI3K-Akt signal pathway genes and the USP34 gene was found in the T-LBL dataset.

Conclusion

Although T-ALL and T-LBL both originate from precursor T-cells and are considered different manifestations of the same disease and the outcome of T-LBL is favorable when using T-ALL-based chemotherapy, there are differences in the gene distribution between T-LBL and T-ALL. It seems that the PI3K-Akt signaling pathway and the USP34 gene play important roles in T-LBL, but medicines targeting the USP34 gene or the PI3K-Akt pathway may be invalid.

The PI3K-Akt-mTOR and Associated Signaling Pathways as Molecular Drivers of Immune-Mediated Inflammatory Skin Diseases: Update on Therapeutic Strategy Using Natural and Synthetic Compounds

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders.

MiR-17- 5p/RRM2 regulated gemcitabine resistance in lung cancer A549 cells

The main objective of this study is to investigate the regulatory roles of the miR-17-5p/RRM2 axis in A549/G+ cells' gemcitabine resistance. The cell viability was determined using CCK8 and clonogenic assays. Gene expression level analysis by RT-qPCR and Western blotting. Cell cycle analysis by flow cytometry. The dual luciferase activity assay was used to verify the target gene of miR-17-5p. In gemcitabine-resistant cell line A549G+, the drug resistance decreased after up-regulation of MiR-17-5p expression. The proportion of cell cycle G1 phase increased, and the S phase decreased. The expression level of cell cycle-related proteins CCNE1, CCNA2, and P21 decreased. The opposite results emerged after the down-regulation of MiR-17-5p expression in gemcitabine-sensitive cell line A549G-. The expression levels of PTEN and PIK3 in A549G+ cells were higher than in A549G-cells, but p-PTEN was lower than that in A549G-. After up-regulating the expression of MiR-17-5p in A549G+, the expression levels of p-PTEN increased, and the expression level of p-AKT decreased. After down-regulating miR-17-5p expression, the opposite results emerged. The dual-luciferase reporter assay and restorative experiments proved that RRM2 is one of the target genes for MiR-17-5p. Our results suggested that the miR-17-5p/RRM2 axis could adjust gemcitabine resistance in A549 cells, and the p-PTEN/PI3K/AKT signal pathway might be involved in this regulatory mechanism.

Bufalin serves as a pharmaceutic that mitigates drug resistance

Intrinsic or acquired drug resistance of tumor cells is the main cause of tumor chemotherapy failure and tumor-related death. Bufalin (BF) is the main active monomer component extracted from the Traditional Chinese Medicine Toad venom (secretions of glands behind the ears and epidermis of bufo gargarizans and Bufo Melanostictus Schneider). It is a cardiotonic steroid with broad-spectrum anti-cancer effects and has been widely used against various malignant tumors in clinical practice. Pharmacological studies also found that BF has the effect of reversing drug resistance, which provides a new perspective for the application of Traditional Chinese Medicine as a chemosensitizer in cancer therapy. This article provides an extensive search and summary of published research on mitigating drug resistance to BF and reviews its potential mechanisms.

ABCB1 and ABCG2 Overexpression Mediates Resistance to the Phosphatidylinositol 3-Kinase Inhibitor HS-173 in Cancer Cell Lines

Constitutive activation of the phosphoinositide-3-kinase (PI3K)/Akt signaling pathway is crucial for tumor growth and progression. As such, this pathway has been an enticing target for drug discovery. Although HS-173 is a potent PI3K inhibitor that halts cancer cell proliferation via G2/M cell cycle arrest, the resistance mechanisms to HS-173 have not been investigated. In this study, we investigated the susceptibility of HS-173 to efflux mediated by the multidrug efflux transporters ABCB1 and ABCG2, which are two of the most well-known ATP-binding cassette (ABC) transporters associated with the development of cancer multidrug resistance (MDR). We found that the overexpression of ABCB1 or ABCG2 significantly reduced the efficacy of HS-173 in human cancer cells. Our data show that the intracellular accumulation of HS-173 was substantially reduced by ABCB1 and ABCG2, affecting G2/M arrest and apoptosis induced by HS-173. More importantly, the efficacy of HS-173 in multidrug-resistant cancer cells could be recovered by inhibiting the drug-efflux function of ABCB1 and ABCG2. Taken together, our study has demonstrated that HS-173 is a substrate for both ABCB1 and ABCG2, resulting in decreased intracellular concentration of this drug, which may have implications for its clinical use.

Investigation of the Underlying Mechanism of Huangqi-Dangshen for Myasthenia Gravis Treatment via Molecular Docking and Network Pharmacology

The herbal pairing of Huangqi and Dangshen (HD) is traditional Chinese herbal medicine and has been widely used in China, especially to treat myasthenia gravis (MG). However, the mechanism of HD on MG is unclear. Aim of the Study. This study aims to investigate HD's possible role in MG treatment. Materials and Methods. The TCMSP database was used to identify the active chemicals and their targets. The GeneCards, DisGeNET, and OMIM databases were used to search for MG-related targets. The STRING database was employed in order to identify the common PPI network targets. We next utilised Cytoscape 3.8.2 for target identification and the DAVID database for gene ontology (GO) function analysis as well as Encyclopaedia of Genomes (KEGG) pathway enrichment analysis on the selected targets. The AutoDock Vina software was used to test the affinity of essential components with the hub gene before concluding that the primary targets were corrected through molecular docking. Results. 41 active compounds were screened from HD, and the number of putative-identified target genes screened from HD was 112. There were 21 target genes that overlapped with the targets of MG, which were postulated to be potential treatment targets. Through further analysis, the results showed that the active compounds from HD (such as 7-methoxy-2-methylisoflavone, quercetin, luteolin, Kaempferol, and isorhamnetin) may achieve the purpose of treating MG by acting on some core targets and related pathways (such as EGFR, FOS, ESR2, MYC, ESR1, CASP3, and IL-6). Molecular docking findings demonstrated that these active molecules have a near-perfect ability to attach to the primary targets. Conclusion. Through network pharmacology, the findings in this study provide light on the coordinated action of several HD formula components, targets, and pathways. It provided a theoretical basis for further study of HD pharmacological action.

Effect of Opioid Receptor Activation and Blockage on the Progression and Response to Treatment of Head and Neck Squamous Cell Carcinoma

Recent studies suggest that opioids have a role in the progression of HNSCC mediated by mu opioid receptors (MOR), however, the effects of their activation or blockage remains unclear. Expression of MOR-1 was explored in seven HNSCC cell lines using Western blotting (WB). XTT cell proliferation and cell migration assays were performed on four selected cell lines (Cal-33, FaDu, HSC-2, and HSC-3), treated with opiate receptor agonist (morphine), antagonist (naloxone), alone and combined with cisplatin. All four selected cell lines display an increased cell proliferation and upregulation of MOR-1 when exposed to morphine. Furthermore, morphine promotes cell migration, while naloxone inhibits it. The effects on cell signaling pathways were analyzed using WB, demonstrating morphine activation of AKT and S6, key proteins in the PI3K/AKT/mTOR axis. A significant synergistic cytotoxic effect between cisplatin and naloxone in all cell lines is observed. In vivo studies of nude mice harboring HSC3 tumor treated with naloxone demonstrate a decrease in tumor volume. The synergistic cytotoxic effect between cisplatin and naloxone is observed in the in vivo studies as well. Our findings suggest that opioids may increase HNSCC cell proliferation via the activation of the PI3K/Akt/mTOR signaling pathway. Moreover, MOR blockage may chemo-sensitize HNSCC to cisplatin.

Purvalanol A induces apoptosis and reverses cisplatin resistance in ovarian cancer

Cisplatin (DDP) resistance limits therapeutic efficacy in patients diagnosed with ovarian cancer. Purvalanol A (Pur) is a novel cyclin-dependent kinase (CDK) inhibitor that has been demonstrated to induce apoptosis in various cancer cells. The present study investigated the effect of the combination treatment of Pur and DDP, and the potential anticancer mechanisms in epithelial ovarian cancer (EOC) cells in vitro and in vivo . We found that Pur enhanced the anti-tumor efficacy of cisplatin in EOC cells. The combination of Pur and DDP had more significant effects on apoptosis induction in EOC cells compared with the individual-treatment groups and the control group. We further demonstrated that the combination of Pur and DDP may trigger apoptosis and autophagy in EOC cells by inducing reactive oxygen species (ROS). And the ROS/Akt/mammalian target of rapamycin signaling pathway as a potential mechanism for the initiation of autophagy induced by combination therapy. Similar results were observed in vivo . These results demonstrated that Pur sensitized the response of EOC cells to cisplatin in vitro and in vivo , reversing the resistance to cisplatin in ovarian cancer.

Epigenetic regulation of autophagy by non-coding RNAs in gastrointestinal tumors: Biological functions and therapeutic perspectives

Cancer is the manifestation of changes and mutations in genetic and epigenetic levels. Non-coding RNAs (ncRNAs) are commonly dysregulated in disease pathogenesis, and their role in cancer has been well-documented. The ncRNAs regulate various molecular pathways and mechanisms in cancer that can lead to induction/inhibition of carcinogenesis. Autophagy is a molecular "self-digestion" mechanism its function can be pro-survival or pro-death in tumor cells. The aim of the present review is to evaluate the role of ncRNAs in regulating autophagy in gastrointestinal tumors. The role of the ncRNA/autophagy axis in affecting the progression of gastric, liver, colorectal, pancreatic, esophageal, and gallbladder cancers is investigated. Both ncRNAs and autophagy mechanisms can function as oncogenic or onco-suppressor and this interaction can determine the growth, invasion, and therapy response of gastrointestinal tumors. ncRNA/autophagy axis can reduce/increase the proliferation of gastrointestinal tumors via the glycolysis mechanism. Furthermore, related molecular pathways of metastasis, such as EMT and MMPs, are affected by the ncRNA/autophagy axis. The response of gastrointestinal tumors to chemotherapy and radiotherapy can be suppressed by pro-survival autophagy, and ncRNAs are essential regulators of this mechanism. miRNAs can regulate related genes and proteins of autophagy, such as ATGs and Beclin-1. Furthermore, lncRNAs and circRNAs down-regulate miRNA expression via sponging to modulate the autophagy mechanism. Moreover, anti-cancer agents can affect the expression level of ncRNAs regulating autophagy in gastrointestinal tumors. Therefore, translating these findings into clinics can improve the prognosis of patients.

Discovery of novel thiazolyl-pyrazolines as dual EGFR and VEGFR-2 inhibitors endowed with in vitro antitumor activity towards non-small lung cancer

New series of thiazolyl-pyrazoline derivatives (7a–7d, 10a–10d and 13a–13f) have been synthesised and assessed for their potential EGFR and VEGFR-2 inhibitory activities. Compounds 10b and 10d exerted potent and selective inhibitory activity towards the two receptor tyrosine kinases; EGFR (IC₅₀ = 40.7 ± 1.0 and 32.5 ± 2.2 nM, respectively) and VEGFR-2 (IC₅₀ = 78.4 ± 1.5 and 43.0 ± 2.4 nM, respectively). The best anti-proliferative activity for the examined thiazolyl-pyrazolines was observed against the non-small lung cancer cells (NSCLC). Compounds 10b and 10d displayed pronounced efficacy against A549 (IC₅₀ = 4.2 and 2.9 µM, respectively) and H441 cell lines (IC₅₀ = 4.8 and 3.8 µM, respectively). Moreover, our results indicated that 10b and 10d were much more effective towards EGFR-mutated NSCLC cell lines (NCI-H1650 and NCI-H1975 cells) than gefitinib. Finally, compounds 10b and 10d induce G2/M cell cycle arrest and apoptosis and inhibit migration in A549 cancerous cells.

Modulation of Genes and MicroRNAs in the Neurospheres of Glioblastoma Cell Lines U343 and T98G Induced by Ionizing Radiation and Temozolomide Therapy

INTRODUCTION

Glioblastoma is the most prevalent primary malignant neoplasm of the central nervous system. It has increased its incidence, while the overall survival remains over 14 months.

PURPOSE

The purpose is to evaluate the expression of the genes EGFR, PTEN, MGMT, and IDH1/2, and microRNAs miR-181b, miR-145, miR-149, and miR-128a in adhered cells (AC) and neurospheres (NS) from cell lines (T98G and U343) submitted to temozolomide (TMZ) and ionizing radiation (IR).

METHODS

T98G and U343 were treated with TMZ, IR, and TMZ+IR. The analysis of gene expression and miRNAs was performed using real-time PCR.

RESULTS

This study demonstrated: a) an improvement in the expression of IDH1 after IR and TMZ + IR in the NS (T98G); b) an increase in the expression of MGMT in NS (T98G) in IR groups and TMZ + IR. The expression of miRNAs results as a) AC (U343) expressed more miR-181b after TMZ, IR, and TMZ + IR; and miR-128a improved after TMZ, IR, and TMZ + IR; b) NS (T98G) after TMZ + IR expressed: miR-181b; miR-149; miR-145 and miR-128a; c) NS (U343) after IR huge expressed miR-149 and miR-145.

CONCLUSION

IR was an independent and determining radioresistance factor in NS. However, we observed no complementarity action of oncomiRs regulation.

Biomarkers in the management of lung cancer: changing the practice of thoracic oncology

Lung cancer currently represents a leading cause of cancer death. Substantial progress achieved in the medical therapy of lung cancer during the last decade has been associated with the advent of targeted therapy, including immunotherapy. The targeted therapy has gradually shifted from drugs suppressing general mechanisms of tumor growth and progression to agents aiming at transforming mechanisms like driver mutations in a particular tumor. Knowledge of the molecular characteristics of a tumor has become an essential component of the more targeted therapeutic approach. There are specific challenges for biomarker determination in lung cancer, in particular a commonly limited size of tumor sample. Liquid biopsy is therefore of particular importance in the management of lung cancer. Laboratory medicine is an indispensable part of multidisciplinary management of lung cancer. Clinical Chemistry and Laboratory Medicine (CCLM) has played and will continue playing a major role in updating and spreading the knowledge in the field.

The Molecular and Cellular Strategies of Glioblastoma and Non-Small-Cell Lung Cancer Cells Conferring Radioresistance

Ionizing radiation (IR) has been shown to play a crucial role in the treatment of glioblastoma (GBM; grade IV) and non-small-cell lung cancer (NSCLC). Nevertheless, recent studies have indicated that radiotherapy can offer only palliation owing to the radioresistance of GBM and NSCLC. Therefore, delineating the major radioresistance mechanisms may provide novel therapeutic approaches to sensitize these diseases to IR and improve patient outcomes. This review provides insights into the molecular and cellular mechanisms underlying GBM and NSCLC radioresistance, where it sheds light on the role played by cancer stem cells (CSCs), as well as discusses comprehensively how the cellular dormancy/non-proliferating state and polyploidy impact on their survival and relapse post-IR exposure.

Signaling pathways and targeted therapies in lung squamous cell carcinoma: mechanisms and clinical trials

Lung cancer is the leading cause of cancer-related death across the world. Unlike lung adenocarcinoma, patients with lung squamous cell carcinoma (LSCC) have not benefitted from targeted therapies. Although immunotherapy has significantly improved cancer patients' outcomes, the relatively low response rate and severe adverse events hinder the clinical application of this promising treatment in LSCC. Therefore, it is of vital importance to have a better understanding of the mechanisms underlying the pathogenesis of LSCC as well as the inner connection among different signaling pathways, which will surely provide opportunities for more effective therapeutic interventions for LSCC. In this review, new insights were given about classical signaling pathways which have been proved in other cancer types but not in LSCC, including PI3K signaling pathway, VEGF/VEGFR signaling, and CDK4/6 pathway. Other signaling pathways which may have therapeutic potentials in LSCC were also discussed, including the FGFR1 pathway, EGFR pathway, and KEAP1/NRF2 pathway. Next, chromosome 3q, which harbors two key squamous differentiation markers SOX2 and TP63 is discussed as well as its related potential therapeutic targets. We also provided some progress of LSCC in epigenetic therapies and immune checkpoints blockade (ICB) therapies. Subsequently, we outlined some combination strategies of ICB therapies and other targeted therapies. Finally, prospects and challenges were given related to the exploration and application of novel therapeutic strategies for LSCC.

Circular RNAs play roles in regulatory networks of cell signaling pathways in human cancers

AIMS

Circular RNAs (circRNAs) are endogenous covalently closed non-coding RNAs produced by reverse splicing of linear RNA. These molecules are highly expressed in mammalian cells and show cell/tissue-specific expression patterns. They are also significantly dysregulated in various cancers and function as oncogenes or tumor suppressors. Emerging evidence reveals that circRNAs contribute to cancer progression via modulating different cell signaling pathways. Nevertheless, the functional significance of circRNAs in cell signaling pathways regulation is still largely elusive. Considering this, shedding light on the multi-pathway effects of circRNAs may improve our understanding of targeted cancer therapy. Here, we discuss how circRNAs regulate the major cell signaling pathways in human cancers.

MATERIALS AND METHODS

We adopted a systematic search in PubMed using the following MeSH terms: circRNAs, non-coding RNAs, lncRNAs, exosomal circRNAs, cancer, and cell signaling.

KEY FINDINGS

We discussed different roles of circRNAs during tumorigenesis in which circRNAs affect tumor development through activating or inactivating certain cell signaling pathways via molecular interactions using various signaling pathways. We also discussed how crosstalk between circRNAs and lncRNAs modulate tumorigenesis and provides a resource for the identification of cancer therapeutic targets.

SIGNIFICANCE

We here elucidated how circRNAs can modulate different cell signaling pathways and play roles in cancer. This can broaden our horizons toward introducing promising prognostic, diagnostic, and therapeutic targets.

The cytotoxicity of karanjin toward breast cancer cells is involved in the PI3K/Akt signaling pathway

Karanjin is a bioactive furanoflavonoid with various pharmacological activities including anticancer activities. However, the effect and the related mechanism of karanjin in breast cancer (BC) have not been revealed. The potential targets of karanjin and BC were predicted using SwissTargetPrediction and GeneCards databases, respectively. The overlapping targets between karanjin and BC were identified using the Venn diagram. DAVID database was used for the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway analysis. Cell viability, proliferation, and apoptosis were examined by MTT (3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-tetrazolium bromide), EdU (5-ethynyl-2'-deoxyuridine) incorporation, and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP digoxigenin nick-end labeling) assays, respectively. The protein levels were measured by western blot analysis. We screened out 28 overlapping targets between karanjin and BC. KEGG analysis showed that the targets of karanjin in BC were associated with the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. Karanjin inhibited cell viability and impeded the proliferative ability of BC cells. Moreover, karanjin treatment induced apoptosis in BC cells. Additionally, karanjin treatment blocked the PI3K/Akt signaling pathway and activation of the PI3K/Akt pathway reversed the antitumor effect of karanjin on BC cells. In conclusion, karanjin exerted antitumor activity in BC cells by regulating the PI3K/Akt signaling pathway.

Network Pharmacology Analysis, Molecular Docking, and In Vitro Verification Reveal the Action Mechanism of Prunella vulgaris L. in Treating Breast Cancer

Background

Prunella vulgaris L. is effective in the treatment of breast cancer (BRCA); however, the underlying mechanism is still unclear. The aim of this study was to elucidate the mechanism of treatment of BRCA by P. vulgaris using network pharmacology and molecular docking technology, and to verify the experimental results using human BRCA MDA-MB-231 cells.

Methods

Active components and action targets of P. vulgaris were determined using the TCMSP™, SwissTarget Prediction™, and TargetNet™ databases. GeneCards™ and OMIM™ provided BRCA targets. After obtaining common targets, a protein-protein interaction (PPI) network was constructed using the STRING™ database, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted using the Xiantao™ academic database. Cytoscape™ was used to construct “single drug-disease-component-target” and “single drug-disease-component-target-pathway” networks. The Human Protein Atlas™ was used to determine protein expression levels in BRCA cell lines. AutoDock tools™ were used to carry out molecular docking for the first 10 targets of quercetin and the PPI network. Finally, the abovementioned results were verified using cell experiments.

Results

We obtained 11 active components, 198 targets, and 179 common targets, including DUOX2, MET, TOP2A, and ERBB3. The results of KEGG pathway analysis screened 188 related signaling pathways and indicated the potential key role of PI3K-Akt and MAPK signaling pathways in the antibreast cancer process of P. vulgaris. The results of molecular docking showed that the first 10 targets of quercetin interacted well with the protein network. Cell experiments showed that quercetin effectively inhibited the proliferation of MDA-MB-231 cells by regulating apoptosis and cell cycle, which may be partly related to the MAPK signaling pathway.

Conclusion

Synergistic effects of multiple components, targets, and pathways on the anti-BRCA activity of P. vulgaris could provide a theoretical basis for further study on its complex anti-BRCA mechanism.

Prospects of targeting PI3K/AKT/mTOR pathway in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has one of the worst prognoses among all malignancies. PI3K/AKT/mTOR signaling pathway, a main downstream effector of KRAS is involved in the regulation of key hallmarks of cancer. We here report that whole-genome analyses demonstrate the frequent involvement of aberrant activations of PI3K/AKT/mTOR pathway components in PDAC patients and critically evaluate preclinical and clinical evidence on the application of PI3K/AKT/mTOR pathway targeting agents. Combinations of these agents with chemotherapeutics or other targeted therapies, including the modulators of cyclin-dependent kinases, receptor tyrosine kinases and RAF/MEK/ERK pathway are also examined. Although human genetic studies and preclinical pharmacological investigations have provided strong evidence on the role of PI3K/AKT/mTOR pathway in PDAC, clinical studies in general have not been as promising. Patient stratification seems to be the key missing point and with the advent of biomarker-guided clinical trials, targeting PI3K/AKT/mTOR pathway could provide valuable assets for treatment of pancreatic cancer patients.

Molecular Pathways and Genomic Landscape of Glioblastoma Stem Cells: Opportunities for Targeted Therapy

Glioblastoma (GBM) is an aggressive tumor of the central nervous system categorized by the World Health Organization as a Grade 4 astrocytoma. Despite treatment with surgical resection, adjuvant chemotherapy, and radiation therapy, outcomes remain poor, with a median survival of only 14-16 months. Although tumor regression is often observed initially after treatment, long-term recurrence or progression invariably occurs. Tumor growth, invasion, and recurrence is mediated by a unique population of glioblastoma stem cells (GSCs). Their high mutation rate and dysregulated transcriptional landscape augment their resistance to conventional chemotherapy and radiation therapy, explaining the poor outcomes observed in patients. Consequently, GSCs have emerged as targets of interest in new treatment paradigms. Here, we review the unique properties of GSCs, including their interactions with the hypoxic microenvironment that drives their proliferation. We discuss vital signaling pathways in GSCs that mediate stemness, self-renewal, proliferation, and invasion, including the Notch, epidermal growth factor receptor, phosphatidylinositol 3-kinase/Akt, sonic hedgehog, transforming growth factor beta, Wnt, signal transducer and activator of transcription 3, and inhibitors of differentiation pathways. We also review epigenomic changes in GSCs that influence their transcriptional state, including DNA methylation, histone methylation and acetylation, and miRNA expression. The constituent molecular components of the signaling pathways and epigenomic regulators represent potential sites for targeted therapy, and representative examples of inhibitory molecules and pharmaceuticals are discussed. Continued investigation into the molecular pathways of GSCs and candidate therapeutics is needed to discover new effective treatments for GBM and improve survival.

Applications of Circulating Tumor Cells and Circulating Tumor DNA in Precision Oncology for Breast Cancers

Liquid biopsies allow for the detection of cancer biomarkers such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). Elevated levels of these biomarkers during cancer treatment could potentially serve as indicators of cancer progression and shed light on the mechanisms of metastasis and therapy resistance. Thus, liquid biopsies serve as tools for cancer detection and monitoring through a simple, non-invasive blood draw, allowing multiple longitudinal sampling. These circulating markers have significant prospects for use in assessing patients’ prognosis, monitoring response to therapy, and developing precision medicine. In addition, single-cell omics of these liquid biopsy markers can be potential tools for identifying tumor heterogeneity and plasticity as well as novel therapeutic targets. In this review, we focus on our current understanding of circulating tumor biomarkers, especially in breast cancer, and the scope of novel sequencing technologies and diagnostic methods for better prognostication and patient stratification to improve patient outcomes.

Treating non-small cell lung cancer by targeting the PI3K signaling pathway

ABSTRACT

The phosphosphatidylinositol-3-kinase (PI3K) signaling pathway is one of the most important intracellular signal transduction pathways affecting cell functions, such as apoptosis, translation, metabolism, and angiogenesis. Lung cancer is a malignant tumor with the highest morbidity and mortality rates in the world. It can be divided into two groups, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC accounts for >85% of all lung cancers. There are currently many clinical treatment options for NSCLC; however, traditional methods such as surgery, chemotherapy, and radiotherapy have not been able to provide patients with good survival benefits. The emergence of molecular target therapy has improved the survival and prognosis of patients with NSCLC. In recent years, there have been an increasing number of studies on NSCLC and PI3K signaling pathways. Inhibitors of various parts of the PI3K pathway have appeared in various phases of clinical trials with NSCLC as an indication. This article focuses on the role of the PI3K signaling pathway in the occurrence and development of NSCLC and summarizes the current clinical research progress and possible development strategies.

Paeonol triggers apoptosis in HeLa cervical cancer cells: the role of mitochondria-related caspase pathway

Paeonol is a biologically active component purified from the root bark of Cortex Moutan that exerts pharmacological effects on the cervical cancer. In this study, we aim to evaluate the anti-cervical cancer capacity of paeonol and to investigate the mechanism driving its anti-cervical cancer effect. Paeonol administration markedly restrained the proliferation and caused apoptosis in HeLa cells. Furthermore, paeonol treatment resulted in a mitochondrial dysfunction in HeLa cells, including the inducing of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) production, and the release of cytochrome c. Moreover, the Bcl-2/Bax proportion was obviously downregulated and cleaved caspase-3 expression was evaluated through paeonol treatment. Additionally, the expression of p-PI3K and p-Akt was noticeably reduced in response to paeonol treatment in HeLa cells. Our findings indicated that paeonol exerts an anticancer potential in HeLa cells, at least in a manner, via triggering the mitochondrial pathway of cellular apoptosis by inhibiting PI3K/Akt signaling. Thus, paeonol has great potential as a promising therapeutic compound to resist human cervical cancer.

Small Molecule Inhibitors in Adult High-Grade Glioma: From the Past to the Future

Glioblastoma is the most common primary malignant tumor in the brain and has a dismal prognosis despite patients accepting standard therapies. Alternation of genes and deregulation of proteins, such as receptor tyrosine kinase, PI3K/Akt, PKC, Ras/Raf/MEK, histone deacetylases, poly (ADP-ribose) polymerase (PARP), CDK4/6, branched-chain amino acid transaminase 1 (BCAT1), and Isocitrate dehydrogenase (IDH), play pivotal roles in the pathogenesis and progression of glioma. Simultaneously, the abnormalities change the cellular biological behavior and microenvironment of tumor cells. The differences between tumor cells and normal tissue become the vulnerability of tumor, which can be taken advantage of using targeted therapies. Small molecule inhibitors, as an important part of modern treatment for cancers, have shown significant efficacy in hematologic cancers and some solid tumors. To date, in glioblastoma, there have been more than 200 clinical trials completed or ongoing in which trial designers used small molecules as monotherapy or combination regimens to correct the abnormalities. In this review, we summarize the dysfunctional molecular mechanisms and highlight the outcomes of relevant clinical trials associated with small-molecule targeted therapies. Based on the outcomes, the main findings were that small-molecule inhibitors did not bring more benefit to newly diagnosed glioblastoma, but the clinical studies involving progressive glioblastoma usually claimed “noninferiority” compared with historical results. However, as to the clinical inferiority trial, similar dosing regimens should be avoided in future clinical trials.

Expert consensus on the clinical application of PI3K/AKT/mTOR inhibitors in the treatment of advanced breast cancer

Phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB or AKT)/mammalian target of rapamycin (mTOR) signaling pathway (PAM pathway) plays an important role in the development of breast cancer and are closely associated with the resistance to endocrine therapy in advanced breast cancer. Therefore, anticancer treatment targeting key molecules in this signaling pathway has become a research hotspot in recent years. Randomized clinical trials have demonstrated that PI3K/AKT/mTOR inhibitors bring significant clinical benefit to patients with advanced breast cancer, especially to those with hormone receptor (HR)-positive, human epidermal growth factor receptor (HER) 2-negative advanced breast cancer. Alpelisib, a PI3K inhibitor, and everolimus, an mTOR inhibitor, have been approved by FDA. Based on their high efficacy and relatively good safety profile, an expanded indication of everolimus in breast cancer has been approved by National Medical Products Administration (NMPA). Alpelisib is expected to be approved in China in the near future. The members of the consensus expert panel reached this consensus to comprehensively define the role of PI3K/AKT/mTOR signaling pathway in breast cancer, efficacy and clinical applications of PI3K/AKT/mTOR inhibitors, management of adverse reactions, and PIK3CA mutation detection, to promote the understanding of PI3K/AKT/mTOR inhibitors for Chinese oncologists, improve clinical decision-making, and prolong the survival of target patient population.

The MYCN inhibitor BGA002 restores the retinoic acid response leading to differentiation or apoptosis by the mTOR block in MYCN-amplified neuroblastoma

BACKGROUND

Neuroblastoma is a deadly childhood cancer, and MYCN-amplified neuroblastoma (MNA-NB) patients have the worst prognoses and are therapy-resistant. While retinoic acid (RA) is beneficial for some neuroblastoma patients, the cause of RA resistance is unknown. Thus, there remains a need for new therapies to treat neuroblastoma. Here we explored the possibility of combining a MYCN-specific antigene oligonucleotide BGA002 and RA as therapeutic approach to restore sensitivity to RA in NB.

METHODS

By molecular and cellular biology techniques, we assessed the combined effect of the two compounds in NB cell lines and in a xenograft mouse model MNA-NB.

RESULTS

We found that MYCN-specific inhibition by BGA002 in combination with RA (BGA002-RA) act synergistically and overcame resistance in NB cell lines. BGA002-RA also reactivated neuron differentiation (or led to apoptosis) and inhibited invasiveness capacity in MNA-NB. Moreover, we found that neuroblastoma had the highest level of mRNA expression of mTOR pathway genes, and that BGA002 led to mTOR pathway inhibition followed by autophagy reactivation in MNA-NB cells, which was strengthened by BGA002-RA. BGA002-RA in vivo treatment also eliminated tumor vascularization in a MNA-NB mouse model and significantly increased survival.

CONCLUSION

Taken together, MYCN modulation mediates the therapeutic efficacy of RA and the development of RA resistance in MNA-NB. Furthermore, by targeting MYCN, a cancer-specific mTOR pathway inhibition occurs only in MNA-NB, thus avoiding the side effects of targeting mTOR in normal cells. These findings warrant clinical testing of BGA002-RA as a strategy for overcoming RA resistance in MNA-NB.

Fakhr Eldeen R, Helwa AA. Pyrimidine-5-carbonitrile based potential anticancer agents as apoptosis inducers through PI3K/AKT axis inhibition in leukaemia K562

A novel series of 4-(4-Methoxyphenyl)-2-(methylthio)pyrimidine-5-carbonitrile was developed linked to an aromatic moiety via N-containing bridge and then evaluated for their cytotoxic activity against MCF-7 and K562 cell lines. Seven compounds exhibited the highest activity against both cell lines where compounds 4d and 7f were the most active against K562 cell line. Exploring their molecular mechanisms by enzyme inhibition assay on PI3Kδ/γ and AKT-1 showed that compound 7f was promising more than 4d with IC₅₀ = 6.99 ± 0.36, 4.01 ± 0.55, and 3.36 ± 0.17 uM, respectively. Also, flowcytometric analysis revealed that 7f caused cell cycle arrest at S-phase followed by caspase 3 dependent apoptosis induction. Mechanistically, compound 7f proved to modulate the expression of PI3K, p-PI3K, AKT, p-AKT, Cyclin D1, and NFΚβ. Furthermore, in-vivo toxicity study indicated good safety profile for 7f. These findings suggest that the trimethoxy derivative 7f has strong potential as a multi-acting inhibitor on PI3K/AKT axis targeting breast cancer and leukaemia.

Natural Compounds as Promising Adjuvant Agents in The Treatment of Gliomas

In humans, glioblastoma is the most prevalent primary malignant brain tumor. Usually, glioblastoma has specific characteristics, such as aggressive cell proliferation and rapid invasion of surrounding brain tissue, leading to a poor patient prognosis. The current therapy-which provides a multidisciplinary approach with surgery followed by radiotherapy and chemotherapy with temozolomide-is not very efficient since it faces clinical challenges such as tumor heterogeneity, invasiveness, and chemoresistance. In this respect, natural substances in the diet, integral components in the lifestyle medicine approach, can be seen as potential chemotherapeutics. There are several epidemiological studies that have shown the chemopreventive role of natural dietary compounds in cancer progression and development. These heterogeneous compounds can produce anti-glioblastoma effects through upregulation of apoptosis and autophagy; allowing the promotion of cell cycle arrest; interfering with tumor metabolism; and permitting proliferation, neuroinflammation, chemoresistance, angiogenesis, and metastasis inhibition. Although these beneficial effects are promising, the efficacy of natural compounds in glioblastoma is limited due to their bioavailability and blood-brain barrier permeability. Thereby, further clinical trials are necessary to confirm the in vitro and in vivo anticancer properties of natural compounds. In this article, we overview the role of several natural substances in the treatment of glioblastoma by considering the challenges to be overcome and future prospects.

Controlled microwave-assisted reactions: A facile synthesis of polyfunctionally substituted phthalazines as dual EGFR and PI3K inhibitors in CNS SNB-75 cell line

Brain tumors are stubborn cancers with poor prognosis and disappointing survival rates. Targeted cancer therapeutics with higher efficacy and lower resistance are highly demanded. An efficient one-pot synthesis of polyfunctionalized phthalazines derivatives was developed by reacting ethyl 1-aryl-5-cyano-1,6-dihydro-4-methyl-6-oxo-3-pyridazine-carboxylates with cinnamonitrile derivatives and the cycloaddition reaction of thieno[3,4-d]pyridazines with activated double or triple bond systems under controlled microwave heating with high yields. The resultant synthesized phthalazines (5a-e, 9 and 13) were tested for their in vitro anti-cancer activities by using in vitro one dose assay at National Cancer institute, USA. Only phthalazine (5b) showed broad spectrum anti-tumor activity against most tested cancer cell lines from all subpanels with mean % GI = 22.61. Interestingly, all tested compounds showed varying growth inhibitory activity against a particular cell line, CNS SNB-75 cell line, but (5b) exhibited the highest growth inhibitory activity against CNS-SNB-75 cell line with (GI% = 108.81) and (IC₅₀ = 3.703 ± 0.2) compared to erlotinib; (IC₅₀ = 12.5 ± 0.68). It caused Pre-G1 apoptosis and growth arrest at S phase. It also increased percentage of the total apoptotic cells in CNS-SNB-75 cell line (39.26%) compared to control cells (2.17%) in the annexin V-FITC experiment. It revealed pronounced EGFR inhibitory activity (IC₅₀ = 47.27 ± 2.41 ng/mL) compared to erlotinib (IC₅₀ = 30.7 ± 1.56 ng/mL). It also inhibited the different PI3K isoforms α, β, γ and δ (with IC₅₀ of 4.39, 13.6, 12.5 and 3.11 μg/mL, respectively compared to LY294002 (with IC₅₀ of 12.7, 8.57, 6.89 and 5.7 μg/mL, respectively). It also caused significant lower protein expression levels of pPI3K, AKT, pAKT and Bcl2 and higher protein expression levels of BAX, Casp3 and Casp9 when compared to untreated cells. Conclusion: Phthalazine (5b) may be an effective, convenient and safe anti-cancer agent acting via proapoptotic and dual EGFR and PI3K kinase inhibitory actions in CNS SNB-75 cell line.

Functions of non-coding RNAs in regulating cancer drug targets

With the development of precision medicine, the efficiency of tumor treatment has been significantly improved. More attention has been paid to targeted therapy and immunotherapy as the key to precision treatment of cancer. Targeting epidermal growth factor receptor (EGFR) has become one of the most important targeted treatments for various cancers. Comparing with traditional chemotherapy drugs, targeting EGFR is highly selective in killing tumor cells with better safety, tolerability and less side effect. In addition, tumor immunotherapy has become the fourth largest tumor therapy after surgery, radiotherapy and chemotherapy, especially immune checkpoint inhibitors. However, these treatments still produce a certain degree of drug resistance. Non-coding RNAs (ncRNAs) were found to play a key role in carcinogenesis, treatment and regulation of the efficacy of anticancer drugs in the past few years. Therefore, in this review, we aim to summarize the targeted treatment of cancers and the functions of ncRNAs in cancer treatment.

Inhibition of FGFR2 enhances chemosensitivity to gemcitabine in cholangiocarcinoma through the AKT/mTOR and EMT signaling pathways

AIM

To investigate the oncogenic role of FGFR2 in carcinogenesis in cholangiocarcinoma (CCA) cells. In addition, the feasibility of using FGFR inhibitors in combination with standard chemotherapy was also explored for the chemosensitizing effect in CCA cells.

MAIN METHODS

Five CCA cell lines were used to screen FGFR2 expression by Western immunoblotting. Two CCA cell lines, KKU-100 and KKU-213A, were knocked down of the FGFR2 gene using siRNA. Cell viability was assessed by the MTS cell proliferation assay. Reproductive cell death was assessed by clonogenic assay. The effects on cell migration and invasion were analyzed by the Transwell chamber method. Cell cycle analysis was performed by flow cytometry. Cell angiogenesis was assessed by HUVEC tube formation and human angiogenesis antibody array analysis. Proteins associated with proliferative and metastatic properties were evaluated by Western blotting.

KEY FINDINGS

Knockdown of FGFR2 suppressed cell growth and colony formation in CCA cells in association with G2/M cell cycle arrest and downregulation of STAT3, cyclin A and cyclin B1. Silencing FGFR2 enhanced the suppressive effect of gemcitabine (Gem) on cell migration and invasion. The combination of infigratinib, an FGFR inhibitor, and Gem, interrupted cell growth, migration, and invasion via downregulation of FGFR/AKT/mTOR pathways and the EMT-associated proteins vimentin and slug. Moreover, the combination also suppressed tube formation together with decreased expression of the proangiogenic factor VEGF.

SIGNIFICANCE

Inhibition of FGFRs by infigratinib enhanced the antitumor effect of Gem in CCA cells through downregulation of the FGFR/AKT/mTOR, FGFR/STAT3 and EMT signaling pathways.

Exosome-liposome hybrid nanoparticle codelivery of TP and miR497 conspicuously overcomes chemoresistant ovarian cancer

Background

Although cisplatin-based chemotherapy has been used as the first-line treatment for ovarian cancer (OC), tumor cells develop resistance to cisplatin during treatment, causing poor prognosis in OC patients. Studies have demonstrated that overactivation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway is involved in tumor chemoresistance and that overexpression of microRNA-497 (miR497) may overcome OC chemotherapy resistance by inhibiting the mTOR pathway. However, the low transcriptional efficiency and unstable chemical properties of miR497 limit its clinical application. Additionally, triptolide (TP) was confirmed to possess a superior killing effect on cisplatin-resistant cell lines, partially through inhibiting the mTOR pathway. Even so, the clinical applications of TP are restricted by serious systemic toxicity and weak water solubility.

Results

Herein, whether the combined application of miR497 and TP could further overcome OC chemoresistance by synergically suppressing the mTOR signaling pathway was investigated. Bioinspired hybrid nanoparticles formed by the fusion of CD47-expressing tumor exosomes and cRGD-modified liposomes (miR497/TP-HENPs) were prepared to codeliver miR497 and TP. In vitro results indicated that the nanoparticles were efficiently taken up by tumor cells, thus significantly enhancing tumor cell apoptosis. Similarly, the hybrid nanoparticles were effectively enriched in the tumor areas and exerted significant anticancer activity without any negative effects in vivo. Mechanistically, they promoted dephosphorylation of the overactivated PI3K/AKT/mTOR signaling pathway, boosted reactive oxygen species (ROS) generation and upregulated the polarization of macrophages from M2 to M1 macrophages.

Conclusion

Overall, our findings may provide a translational strategy to overcome cisplatin-resistant OC and offer a potential solution for the treatment of other cisplatin-resistant tumors.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01264-5.

Limonoids From the Genus Melia (Meliaceae): Phytochemistry, Synthesis, Bioactivities, Pharmacokinetics, and Toxicology

Limonoids, as the vital bioactive chemical compounds in genus Melia plants, have attracted significant attention owing to their exclusive structural characteristics and remarkable biological activity. These compounds can be usually classified into two categories, including the ring-intact group and the ring-C-seco group. Benefiting from the development of separation and analysis technology, more than 200 limonoids have been isolated and identified from this genus. There is growing evidence that limonoids from genus Melia possess diverse pharmacological activities, especially anti-cancer effects, insecticidal activities, and anti-botulism effects. Toosendanin, one of the paramount limonoids, was considered as the pivotal bioactive marker in two medicinal herbs, including Melia toosendan Sieb. et Zucc and Melia azedarach L. In particular, limonoids are found to exhibit non-negligible toxic effects, a finding which needs further research. Besides this, the lack of clinical research data seriously hinders its further development and utilization, and necessary clinical trials should be taken into consideration. In this review, we systematically summarized the phytochemical compounds and their synthesis methods, pharmacological activities, and the structure–activity relationship, pharmacokinetics, and toxicology of genus Melia-derived limonoids. We believe that this up-to-date review could provide scientific evidence for the application of limonoids as agents beneficial to health in future clinical practice.

The Frontline Immunotherapy-Based Treatment of Advanced Clear Cell Renal Cell Carcinoma: Current Evidence and Clinical Perspective

Approximately 400,000 patients are diagnosed with kidney cancer annually worldwide, leading to approximately 170,000 deaths. Renal cell carcinoma (RCC) accounts for more than 90% of kidney cancers. The most common histological subtype is clear cell RCC, which is found in approximately 85% of metastatic RCC cases. The VHL-HIF-VEGF axis is well known; therefore, targeting VEGF has been the mainstay for managing advanced clear cell RCC. Recently, the treatment landscape for advanced clear cell RCC has changed extensively. In particular, immune checkpoint inhibitor-based treatment showed promising results in front-line treatment and became the standard of care. Herein, we review the current evidence on front-line treatment options and discuss the clinical and future perspective.