Phosphoinositide 3-kinase (PI3K) pathway alterations are associated with histologic subtypes and are predictive of sensitivity to PI3K inhibitors in lung cancer preclinical models

Targeting the PI3K/AKT/mTOR pathway in lung cancer: mechanisms and therapeutic targeting

Owing to its high mortality rate, lung cancer (LC) remains the most common cancer worldwide, with the highest malignancy diagnosis rate. The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling (PAM) pathway is a critical intracellular pathway involved in various cellular functions and regulates numerous cellular processes, including growth, survival, proliferation, metabolism, apoptosis, invasion, and angiogenesis. This review aims to highlight preclinical and clinical studies focusing on the PAM signaling pathway in LC and underscore the potential of natural products targeting it. Additionally, this review synthesizes the existing literature and discusses combination therapy and future directions for LC treatment while acknowledging the ongoing challenges in the field. Continuous development of novel therapeutic agents, technologies, and precision medicine offers an increasingly optimistic outlook for the treatment of LC.

Orthotopic Models Using New, Murine Lung Adenocarcinoma Cell Lines Simulate Human Non-Small Cell Lung Cancer Treated with Immunotherapy

Understanding tumor-host immune interactions and the mechanisms of lung cancer response to immunotherapy is crucial. Current preclinical models used to study this often fall short of capturing the complexities of human lung cancer and lead to inconclusive results. To bridge the gap, we introduce two new murine monoclonal lung cancer cell lines for use in immunocompetent orthotopic models. We demonstrate how our cell lines exhibit immunohistochemical protein expression (TTF-1, NapA, PD-L1) and common driver mutations (KRAS, p53, and p110α) seen in human lung adenocarcinoma patients, and how our orthotopic models respond to combination immunotherapy in vivo in a way that closely mirrors current clinical outcomes. These new lung adenocarcinoma cell lines provide an invaluable, clinically relevant platform for investigating the intricate dynamics between tumor and the immune system, and thus potentially contributes to a deeper understanding of immunotherapeutic approaches to lung cancer treatment.

Understanding PI3K/Akt/mTOR signaling in squamous cell carcinoma: mutated PIK3CA as an example

Compared with those in adenocarcinoma, PIK3CA mutations are more common in squamous cell carcinoma (SCC), which arises from stratified squamous epithelia that are usually exposed to adverse environmental factors. Although hotspot mutations in exons 9 and 20 of PIK3CA, including E542K, E545K, H1047L and H1047R, are frequently encountered in the clinic, their clinicopathological meaning remains to be determined in the context of SCC. Considering that few reviews on PIK3CA mutations in SCC are available in the literature, we undertook this review to shed light on the clinical significance of PIK3CA mutations, mainly regarding the implications and ramifications of PIK3CA mutations in malignant cell behavior, prognosis, relapse or recurrence and chemo- or radioresistance of SCC. It should be noted that only those studies regarding SCC in which PIK3CA was mutated were cherry-picked, which fell within the scope of this review. However, the role of mutated PIK3CA in adenocarcinoma has not been discussed. In addition, mutations occurring in other main members of the PI3K-AKT-mTOR signaling pathway other than PIK3CA were also excluded.

mTOR hyperactivity and RICTOR amplification as targets for personalized treatments in malignancies

The increasing knowledge of molecular alterations in malignancies, including mutations and regulatory failures in the mTOR (mechanistic target of rapamycin) signaling pathway, highlights the importance of mTOR hyperactivity as a validated target in common and rare malignancies. This review summarises recent findings on the characterization and prognostic role of mTOR kinase complexes (mTORC1 and mTORC2) activity regarding differences in their function, structure, regulatory mechanisms, and inhibitor sensitivity. We have recently identified new tumor types with RICTOR (rapamycin-insensitive companion of mTOR) amplification and associated mTORC2 hyperactivity as useful potential targets for developing targeted therapies in lung cancer and other newly described malignancies. The activity of mTOR complexes is recommended to be assessed and considered in cancers before mTOR inhibitor therapy, as current first-generation mTOR inhibitors (rapamycin and analogs) can be ineffective in the presence of mTORC2 hyperactivity. We have introduced and proposed a marker panel to determine tissue characteristics of mTOR activity in biopsy specimens, patient materials, and cell lines. Ongoing phase trials of new inhibitors and combination therapies are promising in advanced-stage patients selected by genetic alterations, molecular markers, and/or protein expression changes in the mTOR signaling pathway. Hopefully, the summarized results, our findings, and the suggested characterization of mTOR activity will support therapeutic decisions.

Tumor suppressor PTEN regulation by tobacco smoke in lung squamous-cell carcinoma based on bioinformatics analysis

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN), is a tumor suppressor inactivated in a variety of human cancers. PTEN alteration correlates with lung squamous-cell carcinoma (LUSC) histology. However, it is still unclear how tobacco smoke regulates PTEN in LUSC tissues. In this study, we used free online databases and online tools to analyze PTEN expression and the role of smoking on PTEN alteration in patients with LUSC. We validated bioinformatics data by performing RT-PCR analysis using LUSC patient samples. Our results showed a correlation between the downregulation of PTEN in LUSC tissues compared to normal tissues and smoking exposure. In silico results using online platforms suggest that hsa-mir-301a down-regulates PTEN expression level in smoking patients with LUSC. RT-PCR analysis demonstrated that the PTEN expression was significantly decreased, whereas expression of hsa-mir-301a was up-regulated in the smoker cohort of LUSC tissue compared to adjacent non-cancerous tissues. A significant negative correlation between PTEN and hsa-mir-301a levels was observed in tumour tissues in our cohort of LUSC patients. Our results suggest that the downregulation PTEN gene caused by tobacco smoke-mediated increase of hsa-mir-301a may play an important role in LUSC tumorigenesis.

Syntheses and antitumor activities of neorautenol and shinpterocarpin analogs

The natural products neorautenol and shinpterocarpin and their structural analogs were investigated as novel anticancer agents. Twenty-four analogs, including analogs containing a polar chain and simplified analogs, were synthesized efficiently by a modified method from previous reports. The antitumor screening of synthesized compounds toward six cancer cell lines indicated that compounds 37, 42 and 43 with a dialkylaminoethyl-type side chain exhibited more promising activity than neorautenol and shinpterocarpin against lung and colon cancer lines with a range of 4-9 μM. They showed selective toxicity in normal cells.

Molecular Biology and Therapeutic Targets of Primitive Tracheal Tumors: Focus on Tumors Derived by Salivary Glands and Squamous Cell Carcinoma

Primary tracheal tumors are rare, constituting approximately 0.1-0.4% of malignant diseases. Squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC) account for about two-thirds of these tumors. Despite most primary tracheal cancers being eligible for surgery and/or radiotherapy, unresectable, recurrent and metastatic tumors may require systemic treatments. Unfortunately, the poor response to available chemotherapy as well as the lack of other real therapeutic alternatives affects the quality of life and outcome of patients suffering from more advanced disease. In this condition, target therapy against driver mutations could constitute an alternative to chemotherapy, and may help in disease control. The past two decades have seen extraordinary progress in developing novel target treatment options, shifting the treatment paradigm for several cancers such as lung cancer. The improvement of knowledge regarding the genetic and biological alterations, of major primary tracheal tumors, has opened up new treatment perspectives, suggesting the possible role of biological targeted therapies for the treatment of these rare tumors. The purpose of this review is to outline the state of knowledge regarding the molecular biology, and the preliminary data on target treatments of the main primary tracheal tumors, focusing on salivary-gland-derived cancers and squamous cell carcinoma.

The Case of an Endometrial Cancer Patient with Breast Cancer Who Has Achieved Long-Term Survival via Letrozole Monotherapy

Herein, we present the successful treatment of a 92-year-old woman who experienced recurrent EC in the vaginal stump and para-aortic lymph nodes. The patient was first treated with paclitaxel and carboplatin for recurrent EC, which was abandoned after two cycles of chemotherapy because of G4 hematologic toxicity. Later, the patient was treated with letrozole for early-stage breast cancer, which was diagnosed simultaneously with EC recurrence. After four months of hormonal therapy, a partial response was observed not only in the lesions in the breast, but also those in the vaginal stump and para-aortic lymph nodes. She had no recurrence of breast cancer or EC, even after six years of treatment with letrozole-based hormonal therapy. Subsequent whole-exome sequencing using the genomic DNA isolated from the surgical specimen in the uterine tumor identified several genetic variants, including actionable mutations, such as CTNNB1 (p.S37F), PIK3R1 (p.M582Is_10), and TP53 c.375 + 5G>T. These data suggest that the efficacy of letrozole is mediated by blocking the mammalian target of the rapamycin pathway. The findings of this study, substantiated via genetic analysis, suggest the possibility of long-term disease-free survival, even in elderly patients with recurrent EC, which was thought to be difficult to cure completely.

Unraveling the Impact of Intratumoral Heterogeneity on EGFR Tyrosine Kinase Inhibitor Resistance in EGFR-Mutated NSCLC

The advent of tyrosine kinase inhibitors (TKIs) for treating epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) has been a game changer in lung cancer therapy. However, patients often develop resistance to the drugs within a few years. Despite numerous studies that have explored resistance mechanisms, particularly in regards to collateral signal pathway activation, the underlying biology of resistance remains largely unknown. This review focuses on the resistance mechanisms of EGFR-mutated NSCLC from the standpoint of intratumoral heterogeneity, as the biological mechanisms behind resistance are diverse and largely unclear. There exist various subclonal tumor populations in an individual tumor. For lung cancer patients, drug-tolerant persister (DTP) cell populations may have a pivotal role in accelerating the evolution of tumor resistance to treatment through neutral selection. Cancer cells undergo various changes to adapt to the new tumor microenvironment caused by drug exposure. DTP cells may play a crucial role in this adaptation and may be fundamental in mechanisms of resistance. Intratumoral heterogeneity may also be precipitated by DNA gains and losses through chromosomal instability, and the role of extrachromosomal DNA (ecDNA) may play an important role. Significantly, ecDNA can increase oncogene copy number alterations and enhance intratumoral heterogeneity more effectively than chromosomal instability. Additionally, advances in comprehensive genomic profiling have given us insights into various mutations and concurrent genetic alterations other than EGFR mutations, inducing primary resistance in the context of tumor heterogeneity. Understanding the mechanisms of resistance is clinically crucial since these molecular interlayers in cancer-resistance mechanisms may help to devise novel and individualized anticancer therapeutic approaches.

Pten and p53 Loss in the Mouse Lung Causes Adenocarcinoma and Sarcomatoid Carcinoma

Simple Summary

Lung cancer is the world leading cause of cancer death. Therefore, a better understanding of the disease is needed to improve patient survival. In this work, we have deleted the tumor suppressor genes Pten and Trp53 in adult mouse lungs to analyze its impact on tumor formation. Double mutant mice develop Adenocarcinoma and Pulmonary Sarcomatoid Carcinoma, two different types of Non-Small Cell Carcinoma whose biological relationships are a matter of debate. The former is very common, with various models described and some therapeutic options. The latter is very rare with very poor prognosis, no effective treatment and lack of models reported so far. Interestingly, this study reports the first mouse model of pulmonary sarcomatoid carcinoma available for preclinical research.

Abstract

Lung cancer remains the leading cause of cancer deaths worldwide. Among the Non-Small Cell Carcinoma (NSCLC) category, Adenocarcinoma (ADC) represents the most common type, with different reported driver mutations, a bunch of models described and therapeutic options. Meanwhile, Pulmonary Sarcomatoid Carcinoma (PSC) is one of the rarest, with very poor outcomes, scarce availability of patient material, no effective therapies and no models available for preclinical research. Here, we describe that the combined deletion of Pten and Trp53 in the lungs of adult conditional mice leads to the development of both ADC and PSC irrespective of the lung targeted cell type after naphthalene induced airway epithelial regeneration. Although this model shows long latency periods and incomplete penetrance for tumor development, it is the first PSC mouse model reported so far, and sheds light on the relationships between ADC and PSC and their cells of origin. Moreover, human ADC show strong transcriptomic similarities to the mouse PSC, providing a link between both tumor types and the human ADC.

Individualized Prediction of Drug Response and Rational Combination Therapy in NSCLC Using Artificial Intelligence-Enabled Studies of Acute Phosphoproteomic Changes

We hypothesize that the study of acute protein perturbation in signal transduction by targeted anticancer drugs can predict drug sensitivity of these agents used as single agents and rational combination therapy. We assayed dynamic changes in 52 phosphoproteins caused by an acute exposure (1 hour) to clinically relevant concentrations of seven targeted anticancer drugs in 35 non-small cell lung cancer (NSCLC) cell lines and 16 samples of NSCLC cells isolated from pleural effusions. We studied drug sensitivities across 35 cell lines and synergy of combinations of all drugs in six cell lines (252 combinations). We developed orthogonal machine-learning approaches to predict drug response and rational combination therapy. Our methods predicted the most and least sensitive quartiles of drug sensitivity with an AUC of 0.79 and 0.78, respectively, whereas predictions based on mutations in three genes commonly known to predict response to the drug studied, for example, EGFR, PIK3CA, and KRAS, did not predict sensitivity (AUC of 0.5 across all quartiles). The machine-learning predictions of combinations that were compared with experimentally generated data showed a bias to the highest quartile of Bliss synergy scores (P = 0.0243). We confirmed feasibility of running such assays on 16 patient samples of freshly isolated NSCLC cells from pleural effusions. We have provided proof of concept for novel methods of using acute ex vivo exposure of cancer cells to targeted anticancer drugs to predict response as single agents or combinations. These approaches could complement current approaches using gene mutations/amplifications/rearrangements as biomarkers and demonstrate the utility of proteomics data to inform treatment selection in the clinic.

The PI3K/Akt/mTOR pathway in lung cancer; oncogenic alterations, therapeutic opportunities, challenges, and a glance at the application of nanoparticles

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Lung cancer is the most common and deadliest human malignancies.

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The alterations of PI3K/Akt/mTOR pathway are related to lung cancer progression.

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PI3K axis regulates proliferation, apoptosis, metastasis, and EMT of lung cancer.

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Agents inhibiting components of PI3K axis diminish lung tumor growth and invasion.

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Low efficacy and off-target toxicity could be improved by nanoparticle application.

Lung cancer is the leading cause of cancer-related mortality worldwide. Although the PI3K/Akt/mTOR signaling pathway has recently been considered as one of the most altered molecular pathways in this malignancy, few articles reviewed the task. In this review, we aim to summarize the original data obtained from international research laboratories on the oncogenic alterations in each component of the PI3K/Akt/mTOR pathway in lung cancer. This review also responds to questions on how aberrant activation in this axis contributes to uncontrolled growth, drug resistance, sustained angiogenesis, as well as tissue invasion and metastatic spread. Besides, we provide a special focus on pharmacologic inhibitors of the PI3K/Akt/mTOR axis, either as monotherapy or in a combined-modal strategy, in the context of lung cancer. Despite promising outcomes achieved by using these agents, however, the presence of drug resistance as well as treatment-related adverse events is the other side of the coin. The last section allocates a general overview of the challenges associated with the inhibitors of the PI3K pathway in lung cancer patients. Finally, we comment on the future research aspects, especially in which nano-based drug delivery strategies might increase the efficacy of the therapy in this malignancy.

ACY1 regulating PTEN/PI3K/AKT signaling in the promotion of non-small cell lung cancer progression

Background

Non-small cell lung cancer (NSCLC) has a poor prognosis and is the most common cause of cancer-related deaths worldwide. Aminoacylase 1 (ACY1) plays a promoting role in some cancers, but its role in NSCLC is still unclear.

Methods

Immunohistochemistry, Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting assays were used to determine ACY1 expression patterns in NSCLC tissues and cell lines. The clinical significance of ACY1 in NSCLC was evaluated by χ² test and Kaplan-Meier analysis. MTT, flow cytometry, wound healing, and Transwell assays were performed to assess cell growth, apoptosis, migration, invasion, and tumorigenesis under different treatments. Male athymic BALB/C nude mice were used for xenotransplantation experiments.

Results

The results showed that ACY1 expression was elevated in NSCLC tissue samples and cells, and high ACY1 expression predicted an advanced clinical process and shorter overall survival in patients with NSCLC. Overexpression of ACY1 significantly increased cell growth, migration, invasion, and tumorigenesis, and reduced cell apoptosis, indicating that ACY1 functions as an oncogene in NSCLC. Moreover, ACY1 decreased phosphatase and tensin homolog (PTEN) expression, increased its ubiquitination, and activated PI3K/AKT signaling. Overexpression of PTEN diminished the effects of ACY1 upregulation on cell tumorigenesis promotion.

Conclusions

This study reveals that ACY1 may promote the progression of NSCLC via activating PI3K/AKT signaling in a PTEN-dependent manner. Our study may provide a better understanding of the pathogenesis and development of NSCLC.

Low-Coverage Whole Genome Sequencing of Cell-Free DNA From Immunosuppressed Cancer Patients Enables Tumor Fraction Determination and Reveals Relevant Copy Number Alterations

Cell-free DNA (cfDNA) analysis is a minimally invasive method that can be used to detect genomic abnormalities by directly testing a blood sample. This method is particularly useful for immunosuppressed patients, who are at high risk of complications from tissue biopsy. The cfDNA tumor fraction (TF) varies greatly across cancer type and between patients. Thus, the detection of molecular alterations is highly dependent on the circulating TF. In our study, we aimed to calculate the TF and characterize the copy number aberration (CNA) profile of cfDNA from patients with rare malignancies occurring in immunosuppressed environments or immune-privileged sites. To accomplish this, we recruited 36 patients: 19 patients with non-Hodgkin lymphoma (NHL) who were either human immunodeficiency virus (HIV)-positive or organ transplant recipients, 5 HIV-positive lung cancer patients, and 12 patients with glioma. cfDNA was extracted from the patients' plasma and sequenced using low-coverage whole genome sequencing (LC-WGS). The cfDNA TF was then calculated using the ichorCNA bioinformatic algorithm, based on the CNA profile. In parallel, we performed whole exome sequencing of patient tumor tissue and cfDNA samples with detectable TFs. We detected a cfDNA TF in 29% of immune-suppressed patients (one patient with lung cancer and six with systemic NHL), with a TF range from 8 to 70%. In these patients, the events detected in the CNA profile of cfDNA are well-known events associated with NHL and lung cancer. Moreover, cfDNA CNA profile correlated with the CNA profile of matched tumor tissue. No tumor-derived cfDNA was detected in the glioma patients. Our study shows that tumor genetic content is detectable in cfDNA from immunosuppressed patients with advanced NHL or lung cancer. LC-WGS is a time- and cost-effective method that can help select an appropriate strategy for performing extensive molecular analysis of cfDNA. This technique also enables characterization of CNAs in cfDNA when sufficient tumor content is available. Hence, this approach can be used to collect useful molecular information that is relevant to patient care.

Emerging cellular and molecular interactions between the lung microbiota and lung diseases

With the discovery of the lung microbiota, its study in both pulmonary health and disease has become a vibrant area of emerging research interest. Thus far, most studies have described the lung microbiota composition in lung disease quite well, and some of these studies indicated alterations in lung microbial communities related to the onset and development of lung disease and vice versa. However, the underlying mechanisms, particularly the cellular and molecular links, are still largely unknown. In this review, we highlight the current progress in the complex cellular and molecular mechanisms by which the lung microbiome interacts with immune homeostasis and pulmonary disease pathogenesis to advance our understanding of the elaborate function of the lung microbiota in lung disease. We hope that this work can attract more attention to this still-young yet very promising field to facilitate the identification of new therapeutic targets and provide more innovative therapies. Additional accurate standard-based methodologies and technological breakthroughs are critical to propel the field forward to ultimately achieve the goal of maintaining respiratory health.

Phase I Dose-Escalation Study of the Dual PI3K-mTORC1/2 Inhibitor Gedatolisib in Combination with Paclitaxel and Carboplatin in Patients with Advanced Solid Tumors

PURPOSE

This phase I study evaluated safety, tolerability, pharmacokinetics, and preliminary activity of the PI3K/mTORC1/2 dual inhibitor gedatolisib combined with carboplatin and paclitaxel.

PATIENTS AND METHODS

Patients with advanced solid tumors treated with ≤ 2 prior chemotherapies received intravenous gedatolisib on days 1, 8, 15, and 22 (95, 110, or 130 mg according to dose level); carboplatin (AUC5) on day 8 (day 1 following protocol amendment); and paclitaxel at 80 mg/m² on days 8, 15, and 22 (1, 8, and 15 after amendment), every 28 days. Patients without progressive disease after cycle 6 received maintenance gedatolisib until progression.

RESULTS

Seventeen patients were enrolled [11 ovarian (10 clear cell ovarian cancer, CCOC), 4 endometrial, 2 lung cancers]. Median number of prior chemotherapies was 1 (range, 0-2). Median number of administered cycles was 6 (range, 2-16). Dose-limiting toxicities occurred in 4 patients: 2 (cycle 2 delay due to G2-G3 neutropenia) at 110 mg leading to a change in the treatment schedule, 2 at 130 mg (G2 mucositis causing failure to deliver ≥ 75% of gedatolisib at cycle 1). The recommended phase II dose is gedatolisib 110 mg on days 1, 8, 15, and 22 with carboplatin AUC5 on day 1 and paclitaxel 80 mg/m² on days 1, 8, and 15. The most frequent ≥G3 treatment-related adverse events were neutropenia (35%), anemia (18%), and mucositis (12%). The overall response rate was 65% (80% in CCOC). Pharmacokinetic parameters of gedatolisib were consistent with single-agent results.

CONCLUSIONS

Gedatolisib combined with carboplatin and paclitaxel is tolerable, and preliminary efficacy was observed especially in CCOC.

Mutation Profile Assessed by Next-Generation Sequencing (NGS) of Circulating Tumor DNA (ctDNA) in Chinese Lung Adenocarcinoma Patients: Analysis of Real-World Data

Background

Genomic testing gives guidance to the treatment options in lung adenocarcinoma patients, but some patients are unable to obtain tissue samples due to lesion location or intolerance. Cell-free circulating tumor DNA (ctDNA) tested in plasma or pleural effusion is an advanced access to solve the problem. Our study descriptively identified the genetic variations of advanced Chinese lung adenocarcinoma patients and analyzed the overall survival of patients with EGFR mutations.

Methods

A total of 152 patients' plasma samples were included, and gene mutations were detected by NGS using an Illumina Miseq tabletop sequencer.

Results

Frequencies of altered were EGFR 46.05%, ALK 7.24%, KRAS 6.58%, PIK3CA 6.58%, PTEN 2.63%, HER2 1.97%, MET 1.97%, BRAF 1.32%, NF1 1.32%, and ROS1 0.66%. We identified 48 cases with double or triple driver gene mutations. Multiple mutations were more frequently observed in EGFR and PIK3CA genes. Patients harboring coexistent mutations with an EGFR mutation tended to have a shorter overall survival than those with exclusively EGFR mutations.

Conclusion

EGFR, ALK, and KRAS were common driver gene in Chinese patients with stage IV lung adenocarcinoma. Multiple mutations were detected in the ctDNA samples and involve more EGFR and PIK3CA mutations. The existence of coexisting gene mutations may have adverse effects on the prognosis of patients with EGFR mutation. The unknown mutations discovered by NGS may provide new targets for gene targeting therapy, and ctDNA test by NGS is an effective method for making appropriate treatment choices.

LINC01419-mediated epigenetic silencing of ZIC1 promotes metastasis in hepatocellular carcinoma through the PI3K/Akt signaling pathway

Hepatocellular carcinoma (HCC) is a rapidly growing tumor characterized by a high potential for vascular invasion and metastasis. The purpose of our study is to explore the regulation mechanism of long noncoding RNA (lncRNA) LINC01419 on cell-cycle distribution and metastasis in hepatocellular carcinoma (HCC) by regulating zinc finger of the cerebellum (ZIC1) through PI3K/Akt signaling pathway. Bioinformatics analysis and dual-luciferase reporter assay were used to analyze LINC01419 and related genes in HCC, and their expression in HCC tissues and adjacent normal tissues were determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot. Then, HCC cell lines were subjected to the construction of LINC01419/ZIC1 overexpression/knockdown cells utilizing lentiviral vectors. RIP and ChIP assays were applied to identify the LINC01419-binding protein. BSP and MSP assays were used to determine gene methylation. According to the results, LINC01419 was highly expressed in HCC tissues and cells, while ZIC1 was poorly expressed. LINC01419 targeted and downregulated ZIC1 expression. Furthermore, LINC01419 increased the methylation of ZIC1 promoter and repressed ZIC1 expression. PI3K/Akt signaling pathway was activated by LINC01419 overexpression and ZIC1 knockdown, under which conditions, the HCC cell self-renewal and proliferation were promoted while cell apoptosis was attenuated, accompanied by accelerated formation and metastasis of xenografted tumors in mice. In conclusion, LINC01419 enhances the methylation of ZIC1 promoter, inhibits ZIC1 expression, and activates the PI3K/Akt signaling pathway, thereby enhancing the malignant phenotypes of HCC cells in vitro as well as tumor formation and metastasis in vivo.

PI3K inhibition in breast cancer: Identifying and overcoming different flavors of resistance

The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway is commonly deregulated in many human tumors, including breast cancer. Somatic mutations of the PI3K alpha catalytic subunit (PIK3CA) are the most common cause of pathway hyperactivation. Hence, several PI3K inhibitors have been investigated with one of them, alpelisib, recently approved for the treatment of endocrine sensitive, PIK3CA mutated, metastatic breast cancer. Unfortunately, all patients receiving a PI3K inhibitor eventually develop resistance to these compounds. Mechanisms of resistance include oncogenic PI3K alterations, pathway reactivation through upstream or downstream effectors and enhancement of parallel pro-survival pathways. We review the prognostic and predictive role of PI3K alterations in breast cancer, focusing on resistance to PI3K inhibitors and on biomarkers with potential clinical relevance. We also discuss combination strategies that may overcome resistance to PI3K inhibitors, thus increasing the efficacy of these drugs in breast cancer.

Role of receptor tyrosine kinases mediated signal transduction pathways in tumor growth and angiogenesis-New insight and futuristic vision

In the past two decades, significant progress has been made in the past two decades towards the understanding of the basic mechanisms underlying cancer growth and angiogenesis. In this context, receptor tyrosine kinases (RTKs) play a pivotal role in cell proliferation, differentiation, growth, motility, invasion, and angiogenesis, all of which contribute to tumor growth and progression. Mutations in RTKs lead to abnormal signal transductions in several pathways such as Ras-Raf, MEK-MAPK, PI3K-AKT and mTOR pathways, affecting a wide range of biological functions including cell proliferation, survival, migration and vascular permeability. Increasing evidence demonstrates that multiple kinases are involved in angiogenesis including RTKs such as vascular endothelial growth factor, platelet derived growth factor, epidermal growth factor, insulin-like growth factor-1, macrophage colony-stimulating factor, nerve growth factor, fibroblast growth factor, Hepatocyte Growth factor, Tie 1 & 2, Tek, Flt-3, Flt-4 and Eph receptors. Overactivation of RTKs and its downstream regulation is implicated in tumor initiation and angiogenesis, representing one of the hallmarks of cancer. This review discusses the role of RTKs, PI3K, and mTOR, their involvement, and their implication in pro-oncogenic cellular processes and angiogenesis with effective approaches and newly approved drugs to inhibit their unrestrained action.

TRIM proteins in lung cancer: Mechanisms, biomarkers and therapeutic targets

The tripartite motif (TRIM) family is defined by the presence of a Really Interesting New Gene (RING) domain, one or two B-box motifs and a coiled-coil region. TRIM proteins play key roles in many biological processes, including innate immunity, tumorigenesis, cell differentiation and ontogenetic development. Alterations in TRIM gene and protein levels frequently emerge in a wide range of tumors and affect tumor progression. As canonical E3 ubiquitin ligases, TRIM proteins participate in ubiquitin-dependent proteolysis of prominent components of the p53, NF-κB and PI3K/AKT signaling pathways. The occurrence of ubiquitylation events induced by TRIM proteins sustains internal balance between tumor suppressive and tumor promoting genes. In this review, we summarized the diverse mechanism of TRIM proteins responsible for the most common malignancy, lung cancer. Furthermore, we also discussed recent progress in both the diagnosis and therapeutics of tumors contributed by TRIM proteins.

Prognostic value of the PIK3CA, AKT, and PTEN mutations in oral squamous cell carcinoma: literature review

Over 260,000 (2013) new oral squamous cell carcinoma (OSCC) cases are reported annually worldwide. Despite development in OSCC management, the outcome is still unsatisfactory. Identification of new molecular markers may be of use in prevention, prognosis, and choice of an appropriate therapy. The intracellular molecular signalling pathway of phosphatidyl-inositol-3-kinase is involved in the process of cell growth, differentiation, migration, and survival. The main components of this pathway: PIK3CA (phosphatidylinositol-4,5-bisphosphate-3-kinase catalytic subunit α), PTEN (phosphatase and tensin homologue deleted on chromosome 10), and AKT (serine-threonine kinase) are potential objects of research when introducing new therapeutic agents. The aim of this paper is to evaluate the PIK3CA, PTEN, and AKT gene mutations as prognostic factors in OSCC and to describe their role in aggressive disease progression. This is crucial for oral cancer biology understanding and for indicating which direction new clinical treatments should take.

Concurrent Genetic Alterations and Other Biomarkers Predict Treatment Efficacy of EGFR-TKIs in EGFR-Mutant Non-Small Cell Lung Cancer: A Review

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) greatly improve the survival and quality of life of non-small cell lung cancer (NSCLC) patients with EGFR mutations. However, many patients exhibit de novo or primary/early resistance. In addition, patients who initially respond to EGFR-TKIs exhibit marked diversity in clinical outcomes. With the development of comprehensive genomic profiling, various mutations and concurrent (i.e., coexisting) genetic alterations have been discovered. Many studies have revealed that concurrent genetic alterations play an important role in the response and resistance of EGFR-mutant NSCLC to EGFR-TKIs. To optimize clinical outcomes, a better understanding of specific concurrent gene alterations and their impact on EGFR-TKI treatment efficacy is necessary. Further exploration of other biomarkers that can predict EGFR-TKI efficacy will help clinicians identify patients who may not respond to TKIs and allow them to choose appropriate treatment strategies. Here, we review the literature on specific gene alterations that coexist with EGFR mutations, including common alterations (intra-EGFR [on target] co-mutation, TP53, PIK3CA, and PTEN) and driver gene alterations (ALK, KRAS, ROS1, and MET). We also summarize data for other biomarkers (e.g., PD-L1 expression and BIM polymorphisms) associated with EGFR-TKI efficacy.

Druggable driver gene alterations in redefined large cell carcinoma in Chinese patients: an observational study

Background

Few reports have investigated the genetic status of large cell carcinoma (LCC) in Chinese patients under the 2015 World Health Organization (WHO) classification. We aimed to analyze the distribution of druggable driver gene alterations, including mutations in epidermal growth factor receptor (EGFR), Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), proto-oncogene B-Raf (BRAF), and phosphatidylinositol-4,5 biphosphate 3-kinase catalytic subunit alpha (PIK3CA) and translocations in echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) and ROS proto-oncogene 1 (ROS1), in a large population of patients with LCC under the 2015 WHO classification, and to assess the clinical outcomes of patients with LCC harboring these genetic alterations.

Methods

A cohort of 322 patients with LCC resected between June 2015 and December 2018 was included in this study. The clinical characteristics of the patients and data on the distribution of EGFR, KRAS, BRAF, PIK3CA, EML4-ALK, and ROS1 alterations were retrospectively collected. The disease-free survival (DFS) of patients with LCC was analyzed using the log-rank test.

Results

Among the patients with redefined LCC, the proportion of males was much higher than that of females. Detection of LCC was more frequent in patients >60 years of age (71.4%). Mutations of EGFR were found in 3.6% of the LCC participants, predominantly in non-smokers. Mutations in KRAS were observed in 7.8% of the LCC patients, mainly in males and smokers. Mutations in PIK3CA and EML4-ALK translocations comprised 2.1% and 0.52% of the identified alterations, respectively. No alterations were identified in ROS1 and BRAF. After molecular stratification, no significant difference in DFS was identified between wild-type (WT) and mutation groups (29.91±3.83 vs. 25.33±6.04 months, P=0.48).

Conclusions

Under the 2015 WHO criteria, LCC was more frequently detected in elderly male patients with inferior prognoses. The frequency of EGFR and KRAS mutations was found to be the highest. Mutations in EGFR occurred more frequently in non-smokers, whereas KRAS mutations occurred predominantly in males and smokers. The PIK3CA mutations and EML4-ALK translocations were rare in patients with LCC. Our data revealed that the identification of clinically actionable molecular alterations in LCC may help guide personalized cancer treatment decisions in the future.

Analysis of multigene detection in patients with advanced lung adenocarcinoma using cytological specimens

OBJECTIVE

To investigate the mutation status and clinical characteristics of multigene detection in advanced lung adenocarcinoma using cytological specimens.

MATERIALS AND METHODS

137 advanced lung adenocarcinoma patients with 10 driver genes detection in the Fourth Hospital Hebei Medical University from January 2019 to November 2019 was analysized. 137 cytological specimens including fine-needle aspiration specimens and maligant serous cavity effusion (pleural effusion, peritoneal and pericardial effusion). Ten driver mutations of EGFR, ALK, ROS1, BRAF, KRAS, NRAS, HER2, RET, PIK3CA and MET were detected by the amplification refractory mutation system (ARMS). Meanwhile, 90 of 137 patients were detected with biopsies for parallel gene detection.

RESULTS

78.10 % (107/137) of patients with advanced lung adenocarcinoma harbored at least one of 10 driver mutations. The three main mutations were EGFR (69.16 %, 74/137), ALK (6.57 %, 9/137)and ROS1 (3.65 %, 5/137) mutations. Besides, we found 6 cases including two concomitant mutations: EGFR Exon19 del/HER2 (1/137), EGFR Exon21 L858R/PIK3CA (2/137), EGFR Exon21 L858R/RET (1/137), and ALK/KRAS (2/137). Among 137 patients, women aged 64 or older were more likely to have the mutations (P < 0.05). Female patients (P = 0.003) older or equal to 64 years (P = 0.015) with non-smoking habbit (P = 0.027) were more detected with EGFR mutations, while ALK was more detectable in patients yonger than 64 years. Parallel analysis showed that rates of single EGFR, ALK, ROS1, RET, KRAS, NRAS, HER2, MET mutations and concomitant different mutations were not significantly different between cytological specimens and matched histological specimens.

CONCLUSIONS

In the study, cytological specimens and biopsy samples have a very high coincidence rate of gene detection. EGFR, ALK and ROS1 mutations were the main driver mutations in patients with advanced lung adenocarcinoma.We speculate that EGFR and ALK are more prone to concomitant mutations respectively and the treatment of advanced lung adenocarcinoma patients with concomitant mutations deserves further study. The rate of KRAS, NRAS, BRAF, PIK3CA, RET and MET exon14 skipping mutation were low but may had a significant impact on the targeted therapy of patients with advanced lung adenocarcinoma.

The Fire Within: NF-κB Involvement in Non-Small Cell Lung Cancer

Thirty-four years since its discovery, NF-κB remains a transcription factor with great potential for cancer therapy. However, NF-κB-targeted therapies have yet to find a way to be clinically translatable. Here, we focus exclusively on the role of NF-κB in non-small cell lung cancer (NSCLC) and discuss its contributing effect on cancer hallmarks such as inflammation, proliferation, survival, apoptosis, angiogenesis, epithelial-mesenchymal transition, metastasis, stemness, metabolism, and therapy resistance. In addition, we present our current knowledge of the clinical significance of NF-κB and its involvement in the treatment of patients with NSCLC with chemotherapy, targeted therapies, and immunotherapy.

Inactivation of NF1 Promotes Resistance to EGFR Inhibition in KRAS/NRAS/BRAFV600 -Wild-Type Colorectal Cancer

Through the use of an unbiased, genome-scale CRISPR modifier screen, we identified NF1 suppression as a mechanism of resistance to EGFR inhibition in NRAS/KRAS/BRAFV600 -wild-type colorectal cancer cells. Reduced NF1 expression permitted sustained signaling through the MAPK pathway to promote cell proliferation in the presence of EGFR inhibition. Targeting of MEK in combination with EGFR inhibition leads to synergistic antiproliferative activity. Human KRAS/NRAS/BRAFV600 -wild-type colorectal cancer cell lines with NF1 mutations displayed reduced NF1 mRNA or protein expression and were resistant to EGFR blockade by gefitinib or cetuximab. Cooccurring loss-of-function mutations in PTEN were associated with resistance to dual EGFR/MEK inhibition but cotreatment with a PI3K inhibitor further suppressed proliferation. Loss of NF1 may be a useful biomarker to identify patients that are less likely to benefit from single-agent anti-EGFR therapy in colorectal cancer and may direct potential combination strategies. IMPLICATIONS: This study suggests that further clinical validation of NF1 status as predictor of response to anti-EGFR targeting antibodies in patients with colorectal cancer with KRAS/NRAS/BRAFV600 -wild-type tumors is warranted.

Novel PI3K/Akt/mTOR pathway inhibitors plus radiotherapy: Strategy for non-small cell lung cancer with mutant RAS gene

Non-small cell lung cancer (NSCLC) with RAS -mutant gene has been the most difficult obstacle to overcome. Over 25% of muted lung adenocarcinomas have RAS mutation. The prognosis of NSCLC patients with RAS-mutant genes is always poor because there is no effective drug to suppress RAS-mutant genes. NSCLC patients with RAS-mutant usually develop resistance to radiotherapy and chemotherapy, which in some cases leads to a 5-10% survival rate for non-small cell lung cancer (NSCLC). As little clinical symptom of NSCLC was presented at its early stages, thus it always brings in disappointing treatment outcome. Currently, NSCLC presents the highest morbidity and mortality all over the world. The combination of PI3K/AKT/mTOR pathway inhibitors with radiotherapy is a novel strategy to improve radiosensitivity and therapeutic outcome of NSCLC with a RAS-mutant gene. There have been many preclinical studies and clinical trials on the effect of PI3K/AKT/mTOR pathway inhibitors combined with radiotherapy in NSCLC with a RAS-mutant gene have been reported in the past years. This review provides current knowledge of the combination of PI3K/Akt/mTOR pathway inhibitors with radiotherapy, which prove to be a significant improvement for the treatment of NSCLC patients with RAS mutations and will benefit NSCLC patients with RAS mutations.

Targeting the PI3K/Akt/mTOR pathway in non-small cell lung cancer (NSCLC)

The traditional classification of lung cancer into small cell lung cancer and non-small cell lung cancer (NSCLC) has been transformed with the increased understanding of the molecular alterations and genomic biomarkers that drive the development of lung cancer. Increased activation of the phosphatidylinositol 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) pathway leads to numerous hallmarks of cancer and this pathway represents an attractive target for novel anticancer therapies. In NSCLC, the PI3K/Akt/mTOR pathway has been heavily implicated in both tumorigenesis and the progression of disease. A number of specific inhibitors of PI3K, Akt and mTOR are currently under development and in various stages of preclinical investigation and in early phase clinical trials for NSCLC. Early evidence has yielded disappointing results. Clinical trials, however, have been performed on predominantly molecularly unselected populations, and patient enrichment strategies using high-precision predictive biomarkers in future trials will increase the likelihood of success. A greater understanding of the underlying molecular biology including epigenetic alterations is also crucial to allow for the detection of appropriate biomarkers and guide combination approaches.

Expression profiling revealed keratins and interleukins as potential biomarkers in squamous cell carcinoma of horn in Indian bullocks (Bos indicus)

Horn cancer is most prevalent in Bos indicus and poorly defined genetic landscape makes disease diagnosis and treatment difficult. In this study, RNA-Seq and data analysis using CLC Genomics Workbench was employed to identify biomarkers associated with horn cancer. As a result, a total of 149 genes were found significant differentially expressed in horn cancer samples compared to horn normal samples. The study revealed 'keratins' and 'interleukins' as apex groups of significant differentially expressed genes (DEGs). Functional analysis showed that the upregulated keratins support metastasis of tumor via cell proliferation, migration, and affecting cell stability, while downregulated interleukins along with other associated chemokine receptors deprive the immune response to tumor posing clear path for metastasis of horn cancer. Combi-action of both the group facilitates the tumor microenvironment to reproduce tumorigenesis. Analysis of pathways enriched in DEGs and exemplified protein-protein interaction network indicated actual role of DEGs in horn cancer at a fine level. Important effect of deregulated expression of keratin and interleukin genes in horn cancer enrolling their candidacy as potential biomarkers for horn cancer prognosis. This study appraises the possibility to mitigate horn cancer at fine resolution to extract attainable identification of prognostic molecular portraits.

mTOR in Lung Neoplasms

With the discovery of rapamycin 45 years ago, studies in the mechanistic target of rapamycin (mTOR) field started 2 decades before the identification of the mTOR kinase. Over the years, studies revealed that the mTOR signaling is a master regulator of homeostasis and integrates a variety of environmental signals to regulate cell growth, proliferation, and metabolism. Deregulation of mTOR signaling, particularly hyperactivation, frequently occurs in human tumors. Recent advances in molecular profiling have identified mutations or amplification of certain genes coding proteins involved in the mTOR pathway (eg, PIK3CA, PTEN, STK11, and RICTOR) as the most common reasons contributing to mTOR hyperactivation. These genetic alterations of the mTOR pathway are frequently observed in lung neoplasms and may serve as a target for personalized therapy. mTOR inhibitor monotherapy has met limited clinical success so far; however, rational drug combinations are promising to improve efficacy and overcome acquired resistance. A better understanding of mTOR signaling may have the potential to help translation of mTOR pathway inhibitors into the clinical setting.

Recent Progress in Rare Oncogenic Drivers and Targeted Therapy For Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is frequently associated with oncogenic driver mutations, which play an important role in carcinogenesis and cancer progression. Targeting epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase rearrangements has become standard therapy for patients with these aberrations because of the greater improvement of survival, tolerance, and quality-of-life compared to chemotherapy. Clinical trials for emerging therapies that target other less common driver genes are generating mixed results. Here, we review the literature on rare drivers in NSCLC with frequencies lower than 5% (e.g., ROS1, RET, MET, BRAF, NTRK, HER2, NRG1, FGFR1, PIK3CA, DDR2, and EGFR exon 20 insertions). In summary, targeting rare oncogenic drivers in NSCLC has achieved some success. With the development of new inhibitors that target these rare drivers, the spectrum of targeted therapy has been expanded, although acquired resistance is still an unavoidable problem.

A review of predictive, prognostic and diagnostic biomarkers for non-small-cell lung cancer: towards personalised and targeted cancer therapy

Introduction:

Lung cancer has a high mortality rate mainly due to the lack of early detection or outward signs and symptoms, thereby often progressing to advanced stages (e.g., stage IV) before it is diagnosed. However, if lung cancers can be diagnosed at an early stage and also if clinicians can prospectively identify patients likely to respond to specific treatments, then there is a very high potential to increase patients’ survival. In recent years, several investigations have been conducted to identify cancer biomarkers for lung cancer risk assessment, early detection and diagnosis, the likelihood of identifying the group of patients who will benefit from a particular treatment and monitoring patient response to treatment.

Materials and Methods:

This paper reports on the review of 19 current clinical and emerging biomarkers used in risk assessment, screening for early detection and diagnosis and monitoring the response of treatment of non-small-cell lung cancers.

Conclusion:

The future holds promise for personalised and targeted medicine from prevention, diagnosis to treatment, which take into account individual patient’s variability, though it depends on the development of effective biomarkers interrogating the key aberrant pathways and potentially targetable with molecular targeted or immunologic therapies. Lung cancer biomarkers have the potential to guide clinical decision-making since they can potentially detect the disease early, measure the risk of developing the disease and the risk of progression, provide accurate information of patient response to a specific treatment and are capable of informing clinicians about the likely outcome of a cancer diagnosis independent of the treatment received. Moreover, lung cancer biomarkers are increasingly linked to specific molecular pathway deregulations and/or cancer pathogenesis and can be used to justify the application of certain therapeutic or interventional strategies.

PI3K/mTOR Pathway Inhibition: Opportunities in Oncology and Rare Genetic Diseases

The phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway has been implicated as a cancer target. Big pharma players and small companies have been developing small molecule inhibitors of PI3K and/or mTOR since the 1990s. Although four inhibitors have been approved, many open questions regarding tolerability, patient selection, sensitivity markers, development of resistances, and toxicological challenges still need to be addressed. Besides clear oncological indications, PI3K and mTOR inhibitors have been suggested for treating a plethora of different diseases. In particular, genetically induced PI3K/mTOR pathway activation causes rare disorders, known as overgrowth syndromes, like PTEN (phosphatase and tensin homolog) hamartomas, tuberous sclerosis complex (TSC), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-related overgrowth spectrum (PROS), and activated PI3-Kinase delta syndrome (PI3KCD, APDS). Some of those disorders likeTSC or hemimegalencephaly, which are one of the PROS disorders, also belong to a group of diseases called mTORopathies. This group of syndromes presents with additional neurological manifestations associated with epilepsy and other neuropsychiatric symptoms induced by neuronal mTOR pathway hyperactivation. While PI3K and mTOR inhibitors have been and still are intensively tested in oncology indications, their use in genetically defined syndromes and mTORopathies appear to be promising avenues for a pharmacological intervention.

PTEN in Lung Cancer: Dealing with the Problem, Building on New Knowledge and Turning the Game Around

Lung cancer is the most common malignancy and cause of cancer deaths worldwide, owing to the dismal prognosis for most affected patients. Phosphatase and tensin homolog deleted in chromosome 10 (PTEN) acts as a powerful tumor suppressor gene and even partial reduction of its levels increases cancer susceptibility. While the most validated anti-oncogenic duty of PTEN is the negative regulation of the PI3K/mTOR/Akt oncogenic signaling pathway, further tumor suppressor functions, such as chromosomal integrity and DNA repair have been reported. PTEN protein loss is a frequent event in lung cancer, but genetic alterations are not equally detected. It has been demonstrated that its expression is regulated at multiple genetic and epigenetic levels and deeper delineation of these mechanisms might provide fertile ground for upgrading lung cancer therapeutics. Today, PTEN expression is usually determined by immunohistochemistry and low protein levels have been associated with decreased survival in lung cancer. Moreover, available data involve PTEN mutations and loss of activity with resistance to targeted treatments and immunotherapy. This review discusses the current knowledge about PTEN status in lung cancer, highlighting the prevalence of its alterations in the disease, the regulatory mechanisms and the implications of PTEN on available treatment options.

Radiosensitivity Differences between EGFR Mutant and Wild-Type Lung Cancer Cells are Larger at Lower Doses

In the era of precision medicine, radiotherapy strategies should be determined based on genetic profiles that predict tumor radiosensitivity. Accordingly, pre-clinical research aimed at discovering clinically applicable genetic profiles is needed. However, how a given genetic profile affects cancer cell radiosensitivity is unclear. To address this issue, we performed a pilot in vitro study by utilizing EGFR mutational status as a model for genetic profile. Clonogenic assays of EGFR mutant (n = 6) and wild-type (n = 9) non-small cell lung carcinoma (NSCLC) cell lines were performed independently by two oncologists. Clonogenic survival parameters SF₂, SF₄, SF₆, SF₈, mean inactivation dose (MID), D₁₀, D₅₀, α, and β were obtained using the linear quadratic model. The differences in the clonogenic survival parameters between the EGFR mutant and wild-type cell lines were assessed using the Mann-Whitney U test. As a result, for both datasets, the p values for SF₂, SF₄, D₅₀, α, and α/β were below 0.05, and those for SF₂ were lowest. These data indicate that a genetic profile of NSCLC cell lines might be predictive for their radiation response; i.e., EGFR mutant cell lines might be more sensitive to low dose- and low fraction sized-irradiation.

The dual PI3K/mTOR inhibitor BEZ235 restricts the growth of lung cancer tumors regardless of EGFR status, as a potent accompanist in combined therapeutic regimens

Background

Lung cancer is the most common cause of cancer-related mortality worldwide despite diagnostic improvements and the development of targeted therapies, notably including epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). The phosphoinositide 3-kinase (PI3K)/AKT/mechanistic target of rapamycin (mTOR) signaling has been shown to contribute to tumorigenesis, tumor progression, and resistance to therapy in most human cancer types, including lung cancer. Here, we explored the therapeutic effects of co-inhibition of PI3K and mTOR in non-small-cell lung cancer (NSCLC) cells with different EGFR status.

Methods

The antiproliferative activity of a dual PI3K/mTOR inhibitor BEZ235 was examined by the WST-1 assay and the soft agar colony-formation assay in 2 normal cell lines and 12 NSCLC cell lines: 6 expressing wild-type EGFR and 6 expressing EGFR with activating mutations, including exon 19 deletions, and L858R and T790 M point mutations. The combination indexes of BEZ235 with cisplatin or an EGFR-TKI, BIBW2992 (afatinib), were calculated. The mechanisms triggered by BEZ235 were explored by western blotting analysis. The anti-tumor effect of BEZ235 alone or combined with cisplatin or BIBW2992 were also studied in vivo.

Results

BEZ235 suppressed tumor growth in vitro and in vivo by inducing cell-cycle arrest at G1 phase, but without causing cell death. It also reduced the expression of cyclin D1/D3 by regulating both its transcription and protein stability. Moreover, BEZ235 synergistically enhanced cisplatin-induced apoptosis in NSCLC cells by enhancing or prolonging DNA damage and BIBW2992-induced apoptosis in EGFR-TKI–resistant NSCLC cells containing a second TKI-resistant EGFR mutant.

Conclusions

The dual PI3K/mTOR inhibition by BEZ235 is an effective antitumor strategy for enhancing the efficacy of chemotherapy or targeted therapy, even as a monotherapy, to restrict tumor growth in lung cancer treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1282-0) contains supplementary material, which is available to authorized users.

SWOG S1400B (NCT02785913), a Phase II Study of GDC-0032 (Taselisib) for Previously Treated PI3K-Positive Patients with Stage IV Squamous Cell Lung Cancer (Lung-MAP Sub-Study)

BACKGROUND

S1400B is a biomarker-driven Lung-MAP substudy evaluating the phosphatidylinositol 3-kinase (PI3K) inhibitor taselisib (GDC-0032) in patients with PI3K pathway-activated squamous NSCLC (sqNSCLC).

METHODS

Eligible patients had tumoral phosphatidylinositol-4,5-biphosphate 3 kinase catalytic subunit alpha (PIK3CA) alterations by next-generation sequencing and disease progression after at least one line of platinum-based therapy. Patients received 4-mg taselisib orally daily. The primary analysis population (PAP) was a subset of patients having substitution mutations believed to be associated with clinical benefit of PI3K inhibitors. Primary endpoint was response by Response Evaluation Criteria in Solid Tumors version 1.1; secondary endpoints included progression-free survival, overall survival and duration of response.

RESULTS

Twenty-six patients treated with taselisib comprised the full evaluable population (FEP); 21 patients comprised the PAP. Median age for patients in the FEP was 68 years (range: 53-83 years), 19 were male (73%). The study was closed for futility at interim analysis with one responder in the PAP (5% response rate, 95% confidence interval [CI]: 0%-24%). Two possibly treatment-related deaths (one respiratory failure, one cardiac arrest) were observed; one patient had grades 4 and 11 had grade 3 adverse events. Median progression-free survival and overall survival in the PAP group were 2.9 months (95% CI: 1.8-4.0 mo) and 5.9 months (95% CI: 4.2-7.8 mo), respectively. These numbers were nearly the same in the FEP.

CONCLUSIONS

Study S1400B evaluating taselisib in PIK3CA-altered sqNSCLC failed to meet its primary endpoint and was closed after an interim futility analysis. The trial is unique in cataloguing the diversity of PIK3CA mutations in sqNSCLC.

Phase Ib study of the MEK inhibitor cobimetinib (GDC-0973) in combination with the PI3K inhibitor pictilisib (GDC-0941) in patients with advanced solid tumors

Purpose We investigated the combination of the MEK inhibitor, cobimetinib, and the pan-PI3K inhibitor, pictilisib, in an open-label, phase Ib study. Experimental Design Patients with advanced solid tumors were enrolled in 3 dose escalation schedules: (1) both agents once-daily for 21-days-on 7-days-off ("21/7"); (2) intermittent cobimetinib and 21/7 pictilisib ("intermittent"); or (3) both agents once-daily for 7-days-on 7-days-off ("7/7"). Starting doses for the 21/7, intermittent, and 7/7 schedules were 20/80, 100/130, and 40/130 mg of cobimetinib/pictilisib, respectively. Nine indication-specific expansion cohorts interrogated the recommended phase II dose and schedule. Results Of 178 enrollees (dose escalation: n = 98), 177 patients were dosed. The maximum tolerated doses for cobimetinib/pictilisib (mg) were 40/100, 125/180, and not reached, for the 21/7, intermittent, and 7/7 schedules, respectively. Six dose-limiting toxicities included grade 3 (G3) elevated lipase, G4 elevated creatine phosphokinase, and G3 events including fatigue concurrent with a serious adverse event (SAE) of diarrhea, decreased appetite, and SAEs of hypersensitivity and dehydration. Common drug-related adverse events included nausea, fatigue, vomiting, decreased appetite, dysgeusia, rash, and stomatitis. Pharmacokinetic parameters of the drugs used in combination were unaltered compared to monotherapy exposures. Confirmed partial responses were observed in patients with BRAF-mutant melanoma (n = 1) and KRAS-mutant endometrioid adenocarcinoma (n = 1). Eighteen patients remained on study ≥6 months. Biomarker data established successful blockade of MAP kinase (MAPK) and PI3K pathways. The metabolic response rate documented by FDG-PET was similar to that observed with cobimetinib monotherapy. Conclusions Cobimetinib and pictilisib combination therapy in patients with solid tumors had limited tolerability and efficacy.

Analysis of the frequency of oncogenic driver mutations and correlation with clinicopathological characteristics in patients with lung adenocarcinoma from Northeastern Switzerland

BACKGROUND

Molecular testing of lung adenocarcinoma for oncogenic driver mutations has become standard in pathology practice. The aim of the study was to analyze the EGFR, KRAS, ALK, RET, ROS1, BRAF, ERBB2, MET and PIK3CA mutational status in a representative cohort of Swiss patients with lung adenocarcinoma and to correlate the mutational status with clinicopathological patient characteristics.

METHODS

All patients who underwent molecular testing of newly diagnosed lung adenocarcinoma during a 4-year period (2014-2018) were included. Molecular analyses were performed with Sanger sequencing (n = 158) and next generation sequencing (n = 311). ALK, ROS1 and RET fusion gene analyses were also performed with fluorescence in situ hybridization and immunohistochemistry/immunocytochemistry. Demographic and clinical data were obtained from the medical records.

RESULTS

Of 469 patients with informative EGFR mutation analyses, 90 (19.2%) had EGFR mutations. KRAS mutations were present in 33.9% of the patients, while 6.0% of patients showed ALK rearrangement. BRAF, ERBB2, MET and PIK3CA mutations and ROS1 and RET rearrangements were found in 2.6%, 1.9%, 1.9%, 1.5%, 1.7% and 0.8% of the patients, respectively. EGFR mutation was significantly associated with female gender and never smoking status. ALK translocations were more frequent in never smokers, while KRAS mutations were more commonly found in ever smokers. The association between KRAS mutational status and female gender was statistically significant only on multivariate analysis after adjusting for smoking.

CONCLUSION

The EGFR mutation rate in the current study is among the higher previously reported mutation rates, while the frequencies of KRAS, BRAF, ERBB2 and PIK3CA mutations and ALK, ROS1 and RET rearrangements are similar to the results of previous reports. EGFR and KRAS mutations were significantly associated with gender and smoking. ALK rearrangements showed a significant association with smoking status alone.

Low-pass Whole-genome Sequencing of Circulating Cell-free DNA Demonstrates Dynamic Changes in Genomic Copy Number in a Squamous Lung Cancer Clinical Cohort

PURPOSE

We developed a method to monitor copy number variations (CNV) in plasma cell-free DNA (cfDNA) from patients with metastatic squamous non-small cell lung cancer (NSCLC). We aimed to explore the association between tumor-derived cfDNA and clinical outcomes, and sought CNVs that may suggest potential resistance mechanisms.

EXPERIMENTAL DESIGN

Sensitivity and specificity of low-pass whole-genome sequencing (LP-WGS) were first determined using cell line DNA and cfDNA. LP-WGS was performed on baseline and longitudinal cfDNA of 152 patients with squamous NSCLC treated with chemotherapy, or in combination with pictilisib, a pan-PI3K inhibitor. cfDNA tumor fraction and detected CNVs were analyzed in association with clinical outcomes.

RESULTS

LP-WGS successfully detected CNVs in cfDNA with tumor fraction ≥10%, which represented approximately 30% of the first-line NSCLC patients in this study. The most frequent CNVs were gains in chromosome 3q, which harbors the PIK3CA and SOX2 oncogenes. The CNV landscape in cfDNA with a high tumor fraction generally matched that of corresponding tumor tissue. Tumor fraction in cfDNA was dynamic during treatment, and increases in tumor fraction and corresponding CNVs could be detected before radiographic progression in 7 of 12 patients. Recurrent CNVs, such as MYC amplification, were enriched in cfDNA from posttreatment samples compared with the baseline, suggesting a potential resistance mechanism to pictilisib.

CONCLUSIONS

LP-WGS offers an unbiased and high-throughput way to investigate CNVs and tumor fraction in cfDNA of patients with cancer. It may also be valuable for monitoring treatment response, detecting disease progression early, and identifying emergent clones associated with therapeutic resistance.

New Treatment Options in Advanced Squamous Cell Lung Cancer

The past few years have witnessed a rapid shift in the treatments for patients with squamous cell lung cancers (SQCLCs) after the U.S. Food and Drug Administration approval of a number of immune checkpoint inhibitors as second-line therapies for patients with non-small cell lung cancers. These series of approvals marked the first substantial improvement in overall survival for patients with SQCLC in over a decade. Further gains have been made more recently with the incorporation of immune checkpoint inhibition in the first-line setting, either as monotherapy or in combination with chemotherapy. These advances have, however, exposed existing deficiencies in the management of this disease. Despite a deeper understanding of the genomic alterations that characterize SQCLCs and years of trial work targeting these alterations, personalized therapies remain out of hand. Future studies will continue to focus on identifying targeted approaches to expand the treatment options for our patients.

Acquired Resistance of MET-Amplified Non-small Cell Lung Cancer Cells to the MET Inhibitor Capmatinib

Purpose

Amplified mesenchymal-epithelial transition factor, MET, is a receptor tyrosine kinase (RTK) that has been considered a druggable target in non-small cell lung cancer (NSCLC). Although multiple MET tyrosine kinase inhibitors (TKIs) are being actively developed for MET-driven NSCLC, the mechanisms of acquired resistance to MET-TKIs have not been well elucidated. To understand the mechanisms of resistance and establish therapeutic strategies, we developed an in vitro model using the MET-amplified NSCLC cell line EBC-1.

Materials and Methods

We established capmatinib-resistant NSCLC cell lines and identified alternative signaling pathways using 3′ mRNA sequencing and human phospho-RTK arrays. Copy number alterations were evaluated by quantitative polymerase chain reaction and cell proliferation assay; activation of RTKs and downstream effectors were compared between the parental cell line EBC-1 and the resistant cell lines.

Results

We found that EBC-CR1 showed an epidermal growth factor receptor (EGFR)‒dependent growth and sensitivity to afatinib, an irreversible EGFR TKI. EBC-CR2 cells that had overexpression of EGFR-MET heterodimer dramatically responded to combined capmatinib with afatinib. In addition, EBC-CR3 cells derived from EBC-CR1 cells that activated EGFR with amplified phosphoinositide-3 kinase catalytic subunit α (PIK3CA) were sensitive to combined afatinib with BYL719, a phosphoinositide 3-kinase α (PI3Kα) inhibitor.

Conclusion

Our in vitro studies suggested that activation of EGFR signaling and/or genetic alteration of downstream effectors like PIK3CA were alternative resistance mechanisms used by capmatinib-resistant NSCLC cell lines. In addition, combined treatments with MET, EGFR, and PI3Kα inhibitors may be effective therapeutic strategies in capmatinib-resistant NSCLC patients.

A phase Ib study of pictilisib (GDC-0941) in combination with paclitaxel, with and without bevacizumab or trastuzumab, and with letrozole in advanced breast cancer

BACKGROUND

This phase Ib study (NCT00960960) evaluated pictilisib (GDC-0941; pan-phosphatidylinositol 3-kinase inhibitor) plus paclitaxel, with and without bevacizumab or trastuzumab, or in combination with letrozole, in patients with locally recurrent or metastatic breast cancer.

METHODS

This was a three-part multischedule study. Patients in parts 1 and 2, which comprised 3 + 3 dose escalation and cohort expansion stages, received pictilisib (60-330 mg) plus paclitaxel (90 mg/m2) with and without bevacizumab (10 mg/kg) or trastuzumab (2-4 mg/kg). In part 3, patients received pictilisib (260 mg) plus letrozole (2.5 mg). Primary objectives were evaluation of safety and tolerability, identification of dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) of pictilisib, and recommendation of a phase II dosing regimen. Secondary endpoints included pharmacokinetics and preliminary antitumor activity.

RESULTS

Sixty-nine patients were enrolled; all experienced at least one adverse event (AE). Grade ≥ 3 AEs, serious AEs, and AEs leading to death were reported in 50 (72.5%), 21 (30.4%), and 2 (2.9%) patients, respectively. Six (8.7%) patients reported a DLT, and the MTD and recommended phase II pictilisib doses were established where possible. There was no pictilisib-paclitaxel drug-drug interaction. Two (3.4%) patients experienced complete responses, and 17 (29.3%) patients had partial responses.

CONCLUSIONS

Combining pictilisib with paclitaxel, with and without bevacizumab or trastuzumab, or letrozole, had a manageable safety profile in patients with locally recurrent or metastatic breast cancer. The combination had antitumor activity, and the additive effect of pictilisib supported further investigation in a randomized study.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00960960 . Registered on August 13, 2009.

Krukovine Suppresses KRAS-Mutated Lung Cancer Cell Growth and Proliferation by Inhibiting the RAF-ERK Pathway and Inactivating AKT Pathway

Oncogenic activation of the KRAS gene via point mutations occurs in 20–30% of patients with non-small cell lung cancer (NSCLC). The RAS-RAF-ERK and RAS-PI3K-AKT pathways are the major hyper-activated downstream pathways in RAS mutation, which promotes the unlimited lifecycle of cancer cells and their metastasis in humans. However, the success of targeted therapy is restricted by many factors. Herein, we show a new pharmacological KRAS signaling inhibitor krukovine, which is a small molecular bisbenzylisoquinoline alkaloid, isolated from the bark of Abuta grandifolia (Mart.) Sandw. (Menispermaceae). This alkaloid targets the KRAS downstream signaling pathways in different NSCLC cell lines, such as H460 and A549, which are established by KRAS mutations. In the present study, we initially investigated the anti-cancer activities of krukovine in KRAS-mutated NSCLC cell lines, as well as KRAS wild type cancer cell line and normal lung cell. Results indicated that krukovine can inhibit the growth and dose-dependently inhibit the colony formation capacity and wound healing ability of H460 and A549. This cytotoxic effect is associated with the induction of cell apoptosis and G1 arrest in those cell lines. Krukovine treatment also suppressed the C-RAF, ERK, AKT, PI3K, p70s6k, and mTOR phosphorylation in H460 and A549. This finding suggests that krukovine represses the growth and proliferation of KRAS-mutated cells by inactivating AKT signaling pathway and downregulating the RAF-ERK signaling pathway. This study provides detailed insights into the novel cytotoxic mechanism of an anti-cancer compound from an herbal plant and promotes the anti-cancer potential of krukovine in NSCLC with KRAS mutation.

Targeting the CDK4/6-Rb Pathway Enhances Response to PI3K Inhibition in PIK3CA-Mutant Lung Squamous Cell Carcinoma

PURPOSE

Lung squamous cell carcinoma (LUSC) is a major subtype of non-small cell lung cancer characterized by multiple genetic alterations, particularly PI3K pathway alterations which have been identified in over 50% of LUSC cases. Despite being an attractive target, single-agent PI3K inhibitors have demonstrated modest response in LUSC. Thus, novel combination therapies targeting LUSC are needed.

EXPERIMENTAL DESIGN

PI3K inhibitors alone and in combination with CDK4/6 inhibitors were evaluated in previously established LUSC patient-derived xenografts (PDX) using an in vivo screening method. Screening results were validated with in vivo expansion to 5 to 8 mice per arm. Pharmacodynamics studies were performed to confirm targeted inhibition of compounds.

RESULTS

Consistent with results from The Cancer Genome Atlas analysis of LUSC, genomic profiling of our large cohort of LUSC PDX models identified PI3K pathway alterations in over 50% of the models. In vivo screening using PI3K inhibitors in 12 of these models identified PIK3CA mutation as a predictive biomarker of response (<20% tumor growth compared with baseline/vehicle). Combined inhibition of PI3K and CDK4/6 in models with PIK3CA mutation resulted in greater antitumor effects compared with either monotherapy alone. In addition, the combination of the two drugs achieved targeted inhibition of the PI3K and cell-cycle pathways.

CONCLUSIONS

PIK3CA mutations predict response to PI3K inhibitors in LUSC. Combined PI3K and CDK4/6 inhibition enhances response to either single agents alone. Our findings provide a rationale for clinical testing of combined PI3K and CDK4/6 inhibitors in PIK3CA-mutant LUSC.

Algorithm for the treatment of advanced or metastatic squamous non-small-cell lung cancer: an evidence-based overview

The treatment of squamous non-small-cell lung cancer (nsclc) is evolving. In the past, the backbone of treatment was chemotherapy, with very few other options available. Fortunately, that situation is changing, especially with a better understanding of tumour biology. Various strategies have been tried to improve patient outcomes. The most notable advance must be immunotherapy, which has revolutionized the treatment paradigm for lung cancer in patients without a driver mutation. Immunotherapy is now the treatment of choice in patients who have progressed after chemotherapy and is replacing chemotherapy as upfront therapy in a selected population. Other strategies have also been tried, such as the addition of targeted therapy to chemotherapy. Targeted agents include ramucirumab, an inhibitor of vascular endothelial growth factor receptor 2, and necitumumab, a monoclonal antibody against epithelial growth factor receptor. Recently, advances in molecular profiling have also been applied to tumours of squamous histology, in which multiple genetic alterations, including mutations and amplifications, have been described. Research is actively seeking targetable mutations and testing various therapies in the hopes of further improving prognosis for patients with squamous nsclc. Here, we review the various advances in the treatment of squamous nsclc and present a proposed treatment algorithm based on current evidence.