Coregulation of pathways in lung cancer patients with EGFR mutation: therapeutic opportunities

Low-frequency ERK and Akt activity dynamics are predictive of stochastic cell division events

Understanding the dynamics of intracellular signaling pathways, such as ERK1/2 (ERK) and Akt1/2 (Akt), in the context of cell fate decisions is important for advancing our knowledge of cellular processes and diseases, particularly cancer. While previous studies have established associations between ERK and Akt activities and proliferative cell fate, the heterogeneity of single-cell responses adds complexity to this understanding. This study employed a data-driven approach to address this challenge, developing machine learning models trained on a dataset of growth factor-induced ERK and Akt activity time courses in single cells, to predict cell division events. The most predictive models were developed by applying discrete wavelet transforms (DWTs) to extract low-frequency features from the time courses, followed by using Ensemble Integration, a data integration and predictive modeling framework. The results demonstrated that these models effectively predicted cell division events in MCF10A cells (F-measure=0.524, AUC=0.726). ERK dynamics were found to be more predictive than Akt, but the combination of both measurements further enhanced predictive performance. The ERK model`s performance also generalized to predicting division events in RPE cells, indicating the potential applicability of these models and our data-driven methodology for predicting cell division across different biological contexts. Interpretation of these models suggested that ERK dynamics throughout the cell cycle, rather than immediately after growth factor stimulation, were associated with the likelihood of cell division. Overall, this work contributes insights into the predictive power of intra-cellular signaling dynamics for cell fate decisions, and highlights the potential of machine learning approaches in unraveling complex cellular behaviors.

The potential role of circular RNAs -regulated PI3K signaling in non-small cell lung cancer: Molecular insights and clinical perspective

Non-small cell lung cancer (NSCLC), accounting for more than 80% of all cases, is the predominant form of lung cancer and the leading cause of cancer-related deaths worldwide. Significant progress has been made in diagnostic techniques, surgical interventions, chemotherapy protocols, and targeted therapies at the molecular level, leading to enhanced treatment outcomes in patients with NSCLC. Extensive evidence supports the use of circular RNAs (circRNAs), a specific category of naturally occurring non-coding small RNAs (ncRNAs), for the diagnosis, monitoring of treatment efficacy, and assessment of survival in NSCLC. CircRNAs have been identified to play significant roles in various aspects of cancer formation, either as tumor suppressors or tumor promoters, contributing to cancer development through several signaling pathways, including the phosphoinositide 3-kinases (PI3Ks) pathway. This pathway is well-established because of its regulatory role in essential cellular processes. CircRNAs regulate the PI3K/AKT pathway by targeting diverse cellular elements. This review aims to provide insight into the involvement of several circRNAs linked to the PI3K/AKT pathway in NSCLC.

Direct and selective pharmacological disruption of the YAP-TEAD interface by IAG933 inhibits Hippo-dependent and RAS-MAPK-altered cancers

The YAP-TEAD protein-protein interaction mediates YAP oncogenic functions downstream of the Hippo pathway. To date, available YAP-TEAD pharmacologic agents bind into the lipid pocket of TEAD, targeting the interaction indirectly via allosteric changes. However, the consequences of a direct pharmacological disruption of the interface between YAP and TEADs remain largely unexplored. Here, we present IAG933 and its analogs as potent first-in-class and selective disruptors of the YAP-TEAD protein-protein interaction with suitable properties to enter clinical trials. Pharmacologic abrogation of the interaction with all four TEAD paralogs resulted in YAP eviction from chromatin and reduced Hippo-mediated transcription and induction of cell death. In vivo, deep tumor regression was observed in Hippo-driven mesothelioma xenografts at tolerated doses in animal models as well as in Hippo-altered cancer models outside mesothelioma. Importantly this also extended to larger tumor indications, such as lung, pancreatic and colorectal cancer, in combination with RTK, KRAS-mutant selective and MAPK inhibitors, leading to more efficacious and durable responses. Clinical evaluation of IAG933 is underway.

Advancements in the diagnosis and treatment of sub‑centimeter lung cancer in the era of precision medicine (Review)

Lung cancer is the malignancy with the highest global mortality rate and imposes a substantial burden on society. The increasing popularity of lung cancer screening has led to increasing number of patients being diagnosed with pulmonary nodules due to their potential for malignancy, causing considerable distress in the affected population. However, the diagnosis and treatment of sub-centimeter grade pulmonary nodules remain controversial. The evolution of genetic detection technology and the development of targeted drugs have positioned the diagnosis and treatment of lung cancer in the precision medicine era, leading to a marked improvement in the survival rate of patients with lung cancer. It has been established that lung cancer driver genes serve a key role in the development and progression of sub-centimeter lung cancer. The present review aimed to consolidate the findings on genes associated with sub-centimeter lung cancer, with the intent of serving as a reference for future studies and the personalized management of sub-centimeter lung cancer through genetic testing.

FHL2 promotes the aggressiveness of lung adenocarcinoma by inhibiting autophagy via activation of the PI3K/AKT/mTOR pathway

BACKGROUND

Increasing evidence indicates that four and a half LIM domains 2 (FHL2) plays a crucial role in the progression of various cancers. However, the biological functions and molecular mechanism of FHL2 in lung adenocarcinoma (LUAD) remain unclear.

METHODS

We evaluated the prognostic value of FHL2 in LUAD using public datasets and further confirmed its prognostic value with our clinical data. The biological functions of FHL2 in LUAD were evaluated by in vitro and in vivo experiments. Pathway analysis and rescue experiments were subsequently performed to explore the molecular mechanism by which FHL2 promoted the progression of LUAD.

RESULTS

FHL2 was upregulated in LUAD tissues compared to adjacent normal lung tissues, and FHL2 overexpression was correlated with unfavorable outcomes in patients with LUAD. FHL2 knockdown significantly suppressed the proliferation, migration and invasion of LUAD cells, while FHL2 overexpression had the opposite effect. Mechanistically, FHL2 upregulated the PI3K/AKT/mTOR pathway and subsequently inhibited autophagy in LUAD cells. The effects FHL2 on the proliferation, migration and invasion of LUAD cells are dependent on the inhibition of autophagy, as of induction autophagy attenuated the aggressive phenotype induced by FHL2 overexpression.

CONCLUSIONS

FHL2 promotes the progression of LUAD by activating the PI3K/AKT/mTOR pathway and subsequently inhibiting autophagy, which can be exploited as a potential therapeutic target for LUAD.

Deterministic reprogramming and signaling activation following targeted therapy in non-small cell lung cancer driven by mutations or oncogenic fusions

INTRODUCTION

Targeted therapy is used to treat lung adenocarcinoma caused by epidermal growth factor receptor (EGFR) mutations in the tyrosine kinase domain and rare subtypes (<5%) of non-small cell lung cancer. These subtypes include fusion oncoproteins like anaplastic lymphoma kinase (ALK), ROS1, rearranged during transfection (RET), and other receptor tyrosine kinases (RTKs). The use of diverse selective oral inhibitors, including those targeting rat sarcoma viral oncogene homolog (KRAS) mutations, has significantly improved clinical responses, extending progression-free and overall survival.

AREAS COVERED

Resistance remains a critical issue in lung adenocarcinoma, notably in EGFR mutant, echinoderm microtubule associated protein-like 4 (EML4)-ALK fusion, and KRAS mutant tumors, often associated with epithelial-to-mesenchymal transition (EMT).

EXPERT OPINION

Despite advancements in next generation EGFR inhibitors and EML4-ALK therapies with enhanced brain penetrance and identifying resistance mutations, overcoming resistance has not been abated. Various strategies are being explored to overcome this issue to achieve prolonged cancer remission and delay resistance. Targeting yes-associated protein (YAP) and the mechanisms associated with YAP activation through Hippo-dependent or independent pathways, is desirable. Additionally, the exploration of liquid-liquid phase separation in fusion oncoproteins forming condensates in the cytoplasm for oncogenic signaling is a promising field for the development of new treatments.

KRAS G12C-mutant driven non-small cell lung cancer (NSCLC)

KRAS G12C mutations in non-small cell lung cancer (NSCLC) partially respond to KRAS G12C covalent inhibitors. However, early adaptive resistance occurs due to rewiring of signaling pathways, activating receptor tyrosine kinases, primarily EGFR, but also MET and ligands. Evidence indicates that treatment with KRAS G12C inhibitors (sotorasib) triggers the MRAS:SHOC2:PP1C trimeric complex. Activation of MRAS occurs from alterations in the Scribble and Hippo-dependent pathways, leading to YAP activation. Other mechanisms that involve STAT3 signaling are intertwined with the activation of MRAS. The high-resolution MRAS:SHOC2:PP1C crystallization structure allows in silico analysis for drug development. Activation of MRAS:SHOC2:PP1C is primarily Scribble-driven and downregulated by HUWE1. The reactivation of the MRAS complex is carried out by valosin containing protein (VCP). Exploring these pathways as therapeutic targets and their impact on different chemotherapeutic agents (carboplatin, paclitaxel) is crucial. Comutations in STK11/LKB1 often co-occur with KRAS G12C, jeopardizing the effect of immune checkpoint (anti-PD1/PDL1) inhibitors.

EGFR TKI resistance in lung cancer cells using RNA sequencing and analytical bioinformatics tools

Epidermal Growth Factor Receptor (EGFR) signaling and EGFR mutations play key roles in cancer pathogenesis, particularly in the development of drug resistance. For the ∼20% of all non-small cell lung cancer (NSCLC) patients that harbor an activating mutation, EGFR tyrosine kinase inhibitors (TKIs) provide initial clinical responses. However, long-term efficacy is not possible due to acquired drug resistance. Despite a gradually increasing knowledge of the mechanisms underpinning the development of resistance in tumors, there has been very little success in overcoming it and it is probable that many additional mechanisms are still unknown. Herein, publicly available RNASeq (RNA sequencing) datasets comparing lung cancer cell lines treated with EGFR TKIs until resistance developed with their corresponding parental cells and protein array data from our own EGFR TKI treated xenograft tumors, were analyzed for differential gene expression, with the intent to investigate the potential mechanisms of drug resistance to EGFR TKIs. Pathway analysis, as well as structural disorder analysis of proteins in these pathways, revealed several key proteins, including DUSP1, DUSP6, GAB2, and FOS, that could be targeted using novel combination therapies to overcome EGFR TKI resistance in lung cancer.

Lung cancer associated with combustion particles and fine particulate matter (PM2.5) - The roles of polycyclic aromatic hydrocarbons (PAHs) and the aryl hydrocarbon receptor (AhR)

Air pollution is the leading cause of lung cancer after tobacco smoking, contributing to 20% of all lung cancer deaths. Increased risk associated with living near trafficked roads, occupational exposure to diesel exhaust, indoor coal combustion and cigarette smoking, suggest that combustion components in ambient fine particulate matter (PM2.5), such as polycyclic aromatic hydrocarbons (PAHs), may be central drivers of lung cancer. Activation of the aryl hydrocarbon receptor (AhR) induces expression of xenobiotic-metabolizing enzymes (XMEs) and increase PAH metabolism, formation of reactive metabolites, oxidative stress, DNA damage and mutagenesis. Lung cancer tissues from smokers and workers exposed to high combustion PM levels contain mutagenic signatures derived from PAHs. However, recent findings suggest that ambient air PM2.5 exposure primarily induces lung cancer development through tumor promotion of cells harboring naturally acquired oncogenic mutations, thus lacking typical PAH-induced mutations. On this background, we discuss the role of AhR and PAHs in lung cancer development caused by air pollution focusing on the tumor promoting properties including metabolism, immune system, cell proliferation and survival, tumor microenvironment, cell-to-cell communication, tumor growth and metastasis. We suggest that the dichotomy in lung cancer patterns observed between smoking and outdoor air PM2.5 represent the two ends of a dose-response continuum of combustion PM exposure, where tumor promotion in the peripheral lung appears to be the driving factor at the relatively low-dose exposures from ambient air PM2.5, whereas genotoxicity in the central airways becomes increasingly more important at the higher combustion PM levels encountered through smoking and occupational exposure.

HER3 functions as an effective therapeutic target in triple negative breast cancer to potentiate the antitumor activity of gefitinib and paclitaxel

BACKGROUND

Triple negative breast cancer (TNBC) represents a significant clinical challenge. Chemotherapy remains the mainstay for a large part of TNBC patients, whereas drug resistance and tumor recurrence frequently occur. It is in urgent need to identify novel molecular targets for TNBC and develop effective therapy against the aggressive disease.

METHODS

Immunohistochemistry was performed to examine the expression of HER3 in TNBC samples. Western blots were used to assess protein expression and activation. Cell proliferation and viability were determined by cell growth (MTS) assays. TCGA databases were analyzed to correlate HER3 mRNA expression with the clinical outcomes of TNBC patients. Specific shRNA was used to knockdown HER3 expression. IncuCyte system was utilized to monitor cell growth and migration. LIVE/DEAD Cell Imaging was to detect live and dead cells. HER3 recognition by our anti-HER3 monoclonal antibody (mAb) 4A7 was verified by ELISA, flow cytometry, and co-immunoprecipitation assays. Orthotopic tumor models were established in nude mice to determine the capability of TNBC cells forming tumors and to test if our mAb 4A7 could potentiate the antitumor activity of paclitaxel in vivo.

RESULTS

Elevated expression of HER3 was observed in approximately half of the TNBC specimens and cell lines tested. Analyses of TCGA databases found that the TNBC patients with high HER3 mRNA expression in the tumors showed significantly worse overall survival (OS) and relapse-free survival (RFS) than those with low HER3 expression. Specific knockdown of HER3 markedly inhibited TNBC cell proliferation and mammosphere formation in vitro and tumor growth in vivo. Our mAb 4A7 abrogated heregulin (a ligand for HER3), but not SDF-1 (a ligand for CXCR4)-induced enhancement of TNBC cell migration. Combinations of 4A7 and the EGFR-tyrosine kinase inhibitor (TKI) gefitinib dramatically decreased the levels of phosphorylated HER3, EGFR, Akt, and ERK1/2 in TNBC cells and potently induced growth inhibition and cell death. Moreover, 4A7 in combination with paclitaxel exerted significant antitumor activity against TNBC in vitro and in vivo.

CONCLUSIONS

Our data demonstrate that increased HER3 is an effective therapeutic target for TNBC and our anti-HER3 mAb (4A7) may enhance the efficacy of gefitinib or paclitaxel in TNBC.

Management of diarrhea induced by EGFR-TKIs in advanced lung adenocarcinoma

The identification of Epidermal Growth Factor Receptor (EGFR) mutations in lung adenocarcinoma has facilitated the development of personalized medicine based on oncogenic drivers. EGFR-Tyrosine Kinase Inhibitors (TKIs) are part of the targeted therapy; they impede the phosphorylation of the intracellular tyrosine kinase component of EGFR and consequently block signal transduction pathways. These drugs inhibit the proliferation and survival of tumor cells, leading to long-term progression-free survival and overall survival. Diarrhea is one of the most frequent adverse events associated with EGFR-TKIs, affecting at least 18% of patients and reaching up to 95% in some cases. Diarrhea should be managed carefully given its association with important complications, treatment interruptions, and dose reductions. Moreover, nutritional status and quality of life (QoL) can deteriorate due to severe diarrhea. Changes in diet, such as increment of fiber, supplementation with glutamine, and use of probiotics, may contribute to a decrease in the incidence of diarrhea. Improving the control of diarrhea can provide a significant benefit to the QoL of patients.

Biological insights in non-small cell lung cancer

Lung oncogenesis relies on intracellular cysteine to overcome oxidative stress. Several tumor types, including non-small cell lung cancer (NSCLC), upregulate the system xc- cystine/glutamate antiporter (xCT) through overexpression of the cystine transporter SLC7A11, thus sustaining intracellular cysteine levels to support glutathione synthesis. Nuclear factor erythroid 2-related factor 2 (NRF2) serves as a master regulator of oxidative stress resistance by regulating SLC7A11, whereas Kelch-like ECH-associated protein (KEAP1) acts as a cytoplasmic repressor of the oxidative responsive transcription factor NRF2. Mutations in KEAP1/NRF2 and p53 induce SLC7A11 activation in NSCLC. Extracellular cystine is crucial in supplying the intracellular cysteine levels necessary to combat oxidative stress. Disruptions in cystine availability lead to iron-dependent lipid peroxidation, thus resulting in a type of cell death called ferroptosis. Pharmacologic inhibitors of xCT (either SLC7A11 or GPX4) induce ferroptosis of NSCLC cells and other tumor types. When cystine uptake is impaired, the intracellular cysteine pool can be sustained by the transsulfuration pathway, which is catalyzed by cystathionine-B-synthase (CBS) and cystathionine g-lyase (CSE). The involvement of exogenous cysteine/cystine and the transsulfuration pathway in the cysteine pool and downstream metabolites results in compromised CD8+ T cell function and evasion of immunotherapy, diminishing immune response and potentially reducing the effectiveness of immunotherapeutic interventions. Pyroptosis is a previously unrecognized form of regulated cell death. In NSCLCs driven by EGFR, ALK, or KRAS, selective inhibitors induce pyroptotic cell death as well as apoptosis. After targeted therapy, the mitochondrial intrinsic apoptotic pathway is activated, thus leading to the cleavage and activation of caspase-3. Consequently, gasdermin E is activated, thus leading to permeabilization of the cytoplasmic membrane and cell-lytic pyroptosis (indicated by characteristic cell membrane ballooning). Breakthroughs in KRAS G12C allele-specific inhibitors and potential mechanisms of resistance are also discussed herein.

Insights into EGFR Mutations and Oncogenic KRAS Mutations in Non-Small-Cell Lung Cancer

Genetic mutations can activate different sets of proto-oncogenes and tumor suppressors genes [...].

CircCCDC66: Emerging roles and potential clinical values in malignant tumors

Circular RNAs (circRNAs) are endogenous non-coding RNAs (ncRNAs) with a closed-loop structure. In recent years, circRNAs have become the focus of much research into RNA. CircCCDC66 has been identified as a novel oncogenic circRNA and is up-regulated in a variety of malignant tumors including thyroid cancer, non-small cell carcinoma, gastric cancer, colorectal cancer, renal cancer, cervical cancer, glioma, and osteosarcoma. It mediates cancer progression by regulating epigenetic modifications, variable splicing, transcription, and protein translation. The oncogenicity of circCCDC66 suppresses or promotes the expression of related genes mainly through direct or indirect pathways. This finding suggests that circCCDC66 is a biomarker for cancer diagnosis, prognosis assessment and treatment. However, there is no review on the relationship between circCCDC66 and cancers. Thus, the expression, biological functions, and regulatory mechanisms of circCCDC66 in malignant tumor and non-tumor diseases are summarized. The clinical value and prognostic significance of circCCDC66 are also evaluated, which can provide insights helpful to those exploring new strategies for the early diagnosis and targeted treatment of malignancies.

Case report: Osimertinib administration during pregnancy in a woman with advanced EGFR-mutant non-small cell lung cancer

Lung cancer (LC) is one of the most common causes of death worldwide. The identification of oncogene-addicted driving mutations suitable for targeted therapy has improved clinical outcomes in advanced diseases. Clinical trials, on the other hand, rarely involve vulnerable groups such as pregnant women. We report a 37-year-old woman with advanced non-small cell lung cancer (NSCLC) harboring an exon 19 deletion of EGFR treated with afatinib. After the initial treatment, the patient achieved a complete response and had an unplanned pregnancy. Targeted therapy was withheld during the first trimester and resumed with osimertinib in the second trimester in which the patient developed oligohydramnios and intrauterine growth restriction (IUGR) of the baby. Osimertinib was delayed at two different times during the third trimester with complete resolution of the oligohydramnios. The baby was born at 37.3 weeks of gestation (WOG) with no signs of congenital disorders. After delivery, the mother restarted osimertinib and maintained a complete response. This case suggests that osimertinib could be an acceptable option for tumor control during pregnancy in EGFR-mutant NSCLC. This information do not replace current recommendations for avoiding pregnancy and promoting contraceptive usage in patients receiving any cancer therapy.

A high number of co-occurring genomic alterations detected by NGS is associated with worse clinical outcomes in advanced EGFR-mutant lung adenocarcinoma: Data from LATAM population

BACKGROUND

Co-occurring genomic alterations identified downstream main oncogenic drivers have become more evident since the introduction of next-generation sequencing (NGS) analyses at diagnosis and progression. Emerging evidence has stated that co-occurring genomic alterations at diagnosis might represent de novo and primary resistance mechanisms to tyrosine kinase inhibitors (TKIs) in advanced EGFR-mutant (EGFRm) non-small lung cancer (NSCLC). In this study, we assessed the prognostic role of co-occurring genomic alterations in advanced EGFRm NSCLC.

METHODS

A cohort of 111 patients with advanced NSCLC harboring EGFR-sensitive mutations detected by PCR was analyzed in 5 Latin American oncological centers from January 2019 to December 2020. All eligible patients received upfront therapy with EGFR-TKI. Co-occurring genomic alterations were determined at diagnosis in every patient by the NGS (FoundationOneCDx) comprehensive platform, which evaluates 324 known cancer-related genes.

RESULTS

EGFR exon19 deletion was the most frequent oncogenic driver mutation (60.4 %) detected by NGS. According to the NGS assay, 31 % and 68.3 % of patients had 1-2 and ≥ 3 co-occurring genomic alterations, respectively. The most frequent co-occurring genomic alterations were TP53 mutations (64.9 %) followed by CDKN2AB alterations (13.6 %), BRCA2 (13.6 %), and PTEN (12.7 %) mutations. Baseline central nervous system disease was present in 42.7 % of patients. First- or second-generation EGFR TKIs (gefitinib, afatinib, or erlotinib) were the most common treatment in 67.5 % of patients, while osimertinib was administered in 27.9 % of cases. The median PFS in all evaluated patients was 13.63 months (95 %CI: 11.79-15.52). Using ≥ 3 co-occurring alterations as the cut-off point, patients with ≥ 3 co-occurring genomic alterations showed a median PFS, of 12.7 months (95 %CI: 9.92-15.5) vs 21.3 months (95 %CI: 13.93-NR) in patients with 2 or less co-occurring genomic alterations [HR 3.06, (95 %CI: 1.55-5.48) p = 0.0001]. Also, patients with a TP53 mutation had a shorter PFS, 13.6 (95 %CI: 10.7-15.5) vs 19.2 months (95 %CI: 12.8-NR); in wild type TP53 [HR 2.01 (95 %CI: 1.18-3.74) p = 0.12]. In the multivariate analysis, the number (≥3) of concurrent genomic alterations and ECOG PS of 2 or more were related to a significant risk factor for progression [HR 2.79 (95 %CI: 1.49-5.23) p = 0.001 and HR 2.42 (95 %CI: 1.22-4.80) p = 0.011 respectively].

CONCLUSION

EGFR-mutant NSCLC is not a single oncogene-driven disease in the majority of cases, harboring a higher number of co-occurring genomic alterations. This study finds the number of co-occurring genomic alterations and the presence of TP53 mutations as negative prognostic biomarkers, which confers potentially earlier resistance mechanisms to target therapy.

Location of EGFR exon 20 insertions matters

EGFR exon 20 insertions represent a subgroup of NSCLC patients posed with a therapy dilemma. In this issue of Cancer Cell, Elamin and colleagues demonstrate that only insertions localized in the near loop respond to poziotinib. Pharmacological inhibition of spindle assembly checkpoint components inhibits tumor growth in poziotinib-resistant exon 20 insertions.

Combining EGFR-TKI With SAHA Overcomes EGFR-TKI-Acquired Resistance by Reducing the Protective Autophagy in Non-Small Cell Lung Cancer

Nowadays, lung cancer has the highest mortality worldwide. The emergence of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has greatly improved the survival of patients with non-small cell lung cancer (NSCLC) having EGFR-TKI-sensitive mutations. Unfortunately, acquired resistance happens for most patients. In the present research, we found that EGFR-TKIs (such as gefitinib and osimertinib) can induce autophagy in NSCLC cell lines. Compared with parental sensitive cells, drug-resistant cells have higher autophagy activity. The use of an autophagy inhibitor could enhance the toxicity of gefitinib and osimertinib, which indicates that the enhancement of protective autophagy might be one of the mechanisms of EGFR-TKI resistance in NSCLC. In addition, increased autophagy activity is associated with decreased enhancer of zeste homolog 2 (EZH2) expression. Knockdown of EZH2 or EZH2 inhibitor treatment could lead to increased autophagy in NSCLC cells, indicating that EZH2 is a negative regulator of autophagy. We revealed that the increase in autophagy caused by the reduction of EZH2 was reversed in vitro and in vivo when combining gefitinib or osimertinib with suberoylanilide hydroxamic acid (SAHA), a broad-spectrum histone deacetylase inhibitor (HDACi). In conclusion, our results indicated that the combination of EGFR-TKIs and SAHA may be a new strategy to overcome EGFR-TKIs acquired resistance.

Metformin Enhances TKI-Afatinib Cytotoxic Effect, Causing Downregulation of Glycolysis, Epithelial-Mesenchymal Transition, and EGFR-Signaling Pathway Activation in Lung Cancer Cells

The combination of metformin and TKIs for non-small cell lung cancer has been proposed as a strategy to overcome resistance of neoplastic cells induced by several molecular mechanisms. This study sought to investigate the effects of a second generation TKI afatinib, metformin, or their combination on three adenocarcinoma lung cancer cell lines with different EGFRmutation status. A549, H1975, and HCC827 cell lines were treated with afatinib, metformin, and their combination for 72 h. Afterwards, several parameters were assessed including cytotoxicity, interactions, apoptosis, and EGFR protein levels at the cell membrane and several glycolytic, oxidative phosphorylation (OXPHOS), and EMT expression markers. All cell lines showed additive to synergic interactions for the induction of cytotoxicity caused by the tested combination, as well as an improved pro-apoptotic effect. This effect was accompanied by downregulation of glycolytic, EMT markers, a significant decrease in glucose uptake, extracellular lactate, and a tendency towards increased OXPHOS subunits expression. Interestingly, we observed a better response to the combined therapy in lung cancer cell lines A549 and H1975, which normally have low affinity for TKI treatment. Findings from this study suggest a sensitization to afatinib therapy by metformin in TKI-resistant lung cancer cells, as well as a reduction in cellular glycolytic phenotype.

FAM117A Is a New Prognostic Marker of Lung Adenocarcinoma and Predicts Sensitivity to PD0332991

Lung cancer is the second most common cancer and the leading cause for cancer mortality worldwide. Accelerated cell cycle progression is a well-characterized hallmark for cancer. The present study aims to identify biomarkers for clinical outcomes of lung cancer patients and their sensitivity to CDK inhibitors. To this end, bioinformatics analysis of transcriptome datasets from the Cancer Genome Atlas (TCGA) was first performed to identify survival-related genes; cell proliferation assay, colony formation assay, flow cell cytometry, western blot, EDU labelling, and xenograft models were then used to confirm the potential roles of the identified factors. Our results identified the decreased FAM117A expression as the most significant survival related factor for poor outcome. The cell cycle transition from G1 to S phase was suppressed upon FAM117A overexpression and was promoted upon FAM117A knockdown. Accordingly, the tumor cell growth induced by FAM117A depletion was completely blocked by treatment with PD0332991, which has been approved for cancer therapy. In summary, our work identified FAM117A as a new prognostic marker for poor outcomes of lung cancer patients, predicting sensitivity to PD0332991 treatment.

Tyrosine kinase inhibitors in breast cancer (Review)

Anti-epidermal growth factor receptor (EGFR)-targeted therapy has been intensely researched in the last years, motivated by the favorable results obtained with monoclonal antibodies in HER2-enriched breast cancer (BC) patients. Most researched alternatives of anti-EGFR agents were tyrosine kinase inhibitors (TKIs) and monoclonal antibodies. However, excluding monoclonal antibodies trastuzumab and pertuzumab, the remaining anti-EGFR molecules have exhibited disappointing results, due to the lack of specificity and frequent adverse side effects. TKIs have several advantages, including reduced cardiotoxicity, oral administration and favorable penetration of blood-brain barrier for brain metastatic BC. Lapatinib and neratinib and recently pyrotinib (approved only in China) are the only TKIs from dozens of molecules researched over the years that were approved to be used in clinical practice with limited indications, in a subset of BC patients, single or in combination with other chemotherapy or hormonal therapeutic agents. Improved identification of BC subtypes and improved characterization of aggressive forms (triple negative BC or inflammatory BC) should lead to advancements in shaping of targeted agents to improve the outcome of patients.

First-line osimertinib in patients with epidermal growth factor receptor-mutant non-small-cell lung cancer and with a coexisting low allelic fraction of Thr790Met

AIM OF THE STUDY

The AZENT (NCT02841579) study aimed to assess the efficacy and safety of first-line osimertinib in patients with epidermal growth factor receptor(EGFR)mutation-positive advanced non-small-cell lung cancer (NSCLC) and with a coexisting low allelic fraction of Thr790Met.

METHODS

In this multicentre, single-arm, open-label, phase IIa study, patients with locally advanced or metastatic NSCLC harbouring centrally confirmedEGFR Thr790Met mutation received 80 mg osimertinib daily. The primary end-point was objective response rate (ORR). The secondary end-points included disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety. Efficacy was assessed as per Response Evaluation Criteria in Solid Tumours, version 1.1. Blood samples collected at baseline, end of week 2 and disease progression were analysed using next-generation sequencing. As osimertinib was approved as a first-line therapy during the trial, this led to early termination of phase II; thus, analysis is considered exploratory.

RESULTS

Twenty-two patients were enrolled and received osimertinib. All 22 patients were included in the efficacy and safety analysis. At the data cutoff, 10 (50%) patients remained on treatment. The median duration of follow-up was 24.4 months (interquartile range 12.9 to 26.0). The ORR was 77.3% (17/22 [95% confidence interval {CI} 54.6 to 89.3]). The DCR was 86.4% (19/22, [95% CI 65.1 to 97.1]). The median PFS was 23.1 months (95% CI 14.1 to NE). The median OS was 28·4 months (95% CI 25.6 to NE).

CONCLUSION

Despite early study termination, osimertinib first-line therapy yields an overall PFS of 23.1 months in EGFR-mutant patients harbouring a coexisting low allelic fraction of EGFR Thr790Met mutation.