Transformation from non-small-cell lung cancer to small-cell lung cancer: molecular drivers and cells of origin

New Strategies and Novel Combinations in EGFR TKI-Resistant Non-small Cell Lung Cancer

OPINION STATEMENT

Osimertinib is the current standard-of-care for the first-line treatment of Epidermal Growth Factor Receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). Progression after osimertinib ineluctably occurs, and standard of care treatment options beyond progression have mainly included next-line platinum doublet chemotherapy. With better understanding of the varied molecular mechanisms of resistance to osimertinib, several opportunities for the use of targeted agents are emerging that include MET amplification, observed in 15% of patients, and resistant EGFR mutations, including C797S in 7% of patients. Evidence for the use of targeted therapies in such situations is mostly based on case reports, but clinical trials are being conducted with MET inhibitors, such as amivantamab, an EGFR-MET bispecific antibody, or next-generation EGFR inhibitors, such as patritumab-deruxtecan, a HER3 antibody drug conjugate. In this review, we outline our proposed approach to current clinical practice for patients with EGFR mutant, osimertinib-resistant NSCLC which includes the following potential strategies: - Continuation of osimertinib beyond progression following local ablative treatment of oligoprogressive disease, - Tissue rebiopsy of progressive site and possibly concurrent liquid biopsy to evaluate for mechanism of resistance utilizing comprehensive genomic profiling, -Discussion at a molecular tumor board for assessment for enrollment in clinical trials/expanded access program if available with innovative drugs or possible off-label use of available targeted agents, based on the results of molecular profiling, -If no mechanism of resistance identified, administration of platinum-based chemotherapy with antiangiogenic agents. The role of immunotherapy will also be addressed given the uncertain benefit.

Lung adenocarcinoma relapse with emerging EGFR mutation following complete response of small cell lung cancer warrants routine re-biopsy: A case report

Transformation of small cell lung cancer (SCLC) to lung adenocarcinoma (LUAD) is rarely reported. Here, we report a case initially presented with SCLC and was diagnosed as LUAD when the lesion relapsed at the same site. A 56-year-old patient with SCLC who received etoposide and cisplatin chemotherapy combined with radiotherapy achieved a complete radiological response. After 28 months of stable disease, a computed tomography scan revealed a new lesion at the same site as the primary tumor. Pathological examination suggested a LUAD with an emerging EGFR exon 19 deletion. The patient was then treated with icotinib and achieved a near-complete radiological response. Nineteen months later, the patient developed resistance caused by EGFR T790M mutation and received treatment with osimertinib. At the last follow-up in January 2022, the patient was symptom-free. This case warrants re-biopsy and genetic testing as a routine operation when SCLC relapses at the same site as the primary tumor for an extended period, and prospective investigation is required.

In Vitro Cell Death Mechanisms Induced by Dicoma anomala Root Extract in Combination with ZnPcS4 Mediated-Photodynamic Therapy in A549 Lung Cancer Cells

Globally, lung cancer has remained the leading cause of morbidity and mortality in men and women. To enhance photodynamic therapeutic effects in vitro, the present study was designed to reduce dose-dependence in photodynamic therapy (PDT) and evaluate the anticancer effects of Dicoma anomala (D. anomala) root extracts (i.e., chloroform (Chl), ethyl acetate (EtOAc), and methanol (MeOH)) on A549 lung cancer cells. The most active extract of D. anomala (D.A) was used to establish the 50% inhibitory concentration (IC₅₀), which was further used to evaluate the anticancer efficacy of D.A in combination with ZnPcS₄-mediated PDT IC₅₀. The study further evaluated cell death mechanisms by cell viability/ cytotoxicity (LIVE/DEAD^TM assay), flow cytometry (Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) staining), immunofluorescence (p38, p53, Bax, and caspase 3 expressions), and fluorometric multiplex assay (caspase 8 and 9) 24 h post-treatment with IC₅₀ concentrations of ZnPcS₄-mediated PDT and D.A MeOH root extract. Morphological changes were accompanied by a dose-dependent increase in cytotoxicity, decrease in viability, and proliferation in all experimental models. Apoptosis is the highly favored cell death mechanism observed in combination therapy groups. Apoptotic activities were supported by an increase in the number of dead cells in the LIVE/DEAD^TM assay, and the upregulation of p38, p53, Bax, caspase 3, 8, and 9 apoptotic proteins. In vitro experiments confirmed the cytotoxic and antiproliferative effects of D.A root extracts in monotherapy and in combination with ZnPcS₄-mediated PDT. Taken together, our findings demonstrated that D.A could be a promising therapeutic candidate worth exploring in different types of cancer.

Histologic transformation in lung cancer: when one door shuts, another opens

Histologic transformation (HT) is a major cause of drug resistance to therapy in patients with lung cancer. HTs to small-cell lung cancer (SCLC) have been reported frequently in patients with epidermal growth factor receptor (EGFR)-mutated lung cancer. Although HTs have an impact on the clinical outcomes in patients owing to a high refractoriness to treatments, there is limited data on the prevalence, causes, mechanisms, treatment efficacy, and future treatment strategies. In this review, we assess the literature regarding HTs comprehensively, including those describing EGFR-tyrosine kinase inhibitors, other molecular targeted drugs, and immune checkpoint inhibitors. Furthermore, we discuss the mechanisms of HTs and the lineage plasticity to SCLC and squamous cell carcinoma in lung cancer. In addition, we summarize the treatment efficacy and future perspectives of HTs in patients with lung cancer, and propose better management strategies for this group of patients.

Relationship between the expression of ARHGAP25 and RhoA in non-small cell lung cancer and vasculogenic mimicry

Background

Vasculogenic mimicry (VM) is a recently identified pattern of blood supply to tumor tissue. It has long been considered a functional element in the metastasis and prognosis of malignant tumors. Both Rho GTPase-activating protein 25 (ARHGAP25) and Ras homolog family member A (RhoA) are effective predictors of tumor metastasis. In this study, we examined the expression levels of ARHGAP25 and RhoA and the structure of VM in non-small cell lung cancer (NSCLC). At the same time, we used cytology-related experiments to explore the effect of ARHGAP25 on the migration ability of tumor cells. Furthermore, we analyzed the interaction between the three factors and their association with clinicopathological characteristics and the five-year survival time in patients using statistical tools.

Methods

A total of 130 well-preserved NSCLC and associated paracancerous tumor-free tissues were obtained. Cell colony formation, wound healing, and cytoskeleton staining assays were used to analyze the effect of ARHGAP25 on the proliferation and migration ability of NSCLC cells. Immunohistochemical staining was used to determine the positivity rates of ARHGAP25, RhoA, and VM. Statistical software was used to examine the relationships between the three factors and clinical case characteristics, overall survival, and disease-free survival.

Results

Cell colony formation, wound healing, and cytoskeleton staining assays confirmed that ARHGAP25 expression affects the proliferation and migratory abilities of NSCLC cells. ARHGAP25 positivity rates in NSCLC and paracancerous tumor-free tissues were 48.5% and 63.1%, respectively, whereas RhoA positivity rates were 62.3% and 18.5%, respectively. ARHGAP25 had a negative relationship with RhoA and VM, whereas RhoA and VM had a positive relationship (P < 0.05). ARHGAP25, RhoA, and VM affected the prognosis of patients with NSCLC (P < 0.05) according to Kaplan–Meier of survival time and Cox regression analyses. Furthermore, lowering ARHGAP25 expression increased NSCLC cell proliferation and migration.

Conclusions

ARHGAP25 and RhoA expression is associated with VM and may be of potential value in predicting tumor metastasis, prognosis, and targeted therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02179-5.

Prediction of Resistance Mutations Against Upcoming Anaplastic Lymphoma Kinase Inhibitors

BACKGROUND

Chromosomal aberrations involving the anaplastic lymphoma kinase (ALK) gene have been observed in approximately 4% of patients with non-small cell lung cancer (NSCLC). Although these patients clinically benefit from treatment with various ALK tyrosine kinase inhibitors (ALK-TKIs), none of these can inhibit the development of resistance mutations. Considering inevitable drug resistance and the variety of available ALK-TKIs, it is necessary to predict the pattern of drug-resistance mutations to determine the optimal treatment strategy.

OBJECTIVE

We aimed to establish a polymerase chain reaction (PCR)-based system to predict the development of resistance mutations against ALK-TKIs and identify therapeutic strategies using the upcoming ALK-TKIs repotrectinib (TPX-0005) and ensartinib (X-396) following recurrence on first-line alectinib treatment for ALK-positive NSCLC.

METHODS

An error-prone PCR-based method for predicting drug resistance mutations was established and the half-maximal inhibitory concentration (IC₅₀) values of the predicted ALK mutations were evaluated in a Ba/F3 cell-based assay.

RESULTS

We predicted several resistance mutations against repotrectinib and ensartinib, and demonstrated that the next-generation ALK-TKI TPX-0131, was active against repotrectinib-resistant mutations and that the FLT3 inhibitor gilteritinib was active against ensartinib-resistant mutations.

CONCLUSIONS

We developed a PCR-based system for predicting drug resistance mutations. When this system was applied to repotrectinib and ensartinib, the results suggested that these drugs can be used for the second-line treatment of ALK-positive NSCLC. Predicting resistance mutations against TKIs will provide useful information to aid in the development of effective therapeutic strategies.

Femoral head metastases from primary mucinous lung adenocarcinoma with left hip pain: A case report and literature review

Background

Primary mucinous lung adenocarcinoma, a subtype of lung adenocarcinoma, is extremely rare. Currently, as there are no specific diagnostic features, it is easy to delay the diagnosis or even to misdiagnose when atypical symptoms are present.

Case summary

This case details a patient with primary mucinous lung adenocarcinoma and metastasis to the femoral head. The sole symptom was left hip pain and the initial diagnosis was isolated femoral head necrosis.

Conclusions

By presenting this rare case report and the experiences learned from it, we hope to assist clinicians to identify bone metastasis cases with non-typical symptoms in order to make the correct diagnosis as soon as possible.

I, Deniega FM, Delica K, Fernandez K, Lebrilla CB, Manalo MN, Heralde III FM, Completo GCJ, Nacario RC. Biological Assay-Guided Fractionation and Mass Spectrometry-Based Metabolite Profiling of Annona muricata L. Cytotoxic Compounds against Lung Cancer A549 Cell Line

Annona muricata L. (Guyabano) leaves are reported to exhibit anticancer activity against cancer cells. In this study, the ethyl acetate extract from guyabano leaves was purified through column chromatography, and the cytotoxic effects of the semi-purified fractions were evaluated against A549 lung cancer cells using in vitro MTS cytotoxicity and scratch/wound healing assays. Fractions F15-16C and F15-16D exhibited the highest anticancer activity in the MTS assay, with % cytotoxicity values of 99.6% and 99.4%, respectively. The bioactivity of the fractions was also consistent with the results of the scratch/wound healing assay. Moreover, untargeted metabolomics was employed on the semi-purified fractions to determine the putative compounds responsible for the bioactivity. The active fractions were processed using LC-MS/MS analysis with the integration of the following metabolomic tools: MS-DIAL (for data processing), MetaboAnalyst (for data analysis), GNPS (for metabolite annotation), and Cytoscape (for network visualization). Results revealed that the putative compounds with a significant difference between active and inactive fractions in PCA and OPLS-DA models were pheophorbide A and diphenylcyclopropenone.

Acquired semi-squamatization during chemotherapy suggests differentiation as a therapeutic strategy for bladder cancer

Cisplatin-based chemotherapy remains the primary treatment for unresectable and metastatic muscle-invasive bladder cancers (MIBCs). However, tumors frequently develop chemoresistance. Here, we established a primary and orthotopic MIBC mouse model with gene-edited organoids to recapitulate the full course of chemotherapy in patients. We found that partial squamous differentiation, called semi-squamatization, is associated with acquired chemoresistance in both mice and human MIBCs. Multi-omics analyses showed that cathepsin H (CTSH) is correlated with chemoresistance and semi-squamatization. Cathepsin inhibition by E64 treatment induces full squamous differentiation and pyroptosis, and thus specifically restrains chemoresistant MIBCs. Mechanistically, E64 treatment activates the tumor necrosis factor pathway, which is required for the terminal differentiation and pyroptosis of chemoresistant MIBC cells. Our study revealed that semi-squamatization is a type of lineage plasticity associated with chemoresistance, suggesting that differentiation via targeting of CTSH is a potential therapeutic strategy for the treatment of chemoresistant MIBCs.

Transformation of adenocarcinoma to squamous cell carcinoma as a source of EGFR-TKI resistance: A case report and literature review

In general, non-small cell lung cancer patients with epidermal growth factor receptor (EGFR) mutations respond to tyrosine kinase inhibitors (TKIs). However, most patients experience resistance within 1-2 years after treatment. The histological explanation for the acquired resistance is that malignant transformation occurs during cancer treatment. To date, the transformation from adenocarcinoma to squamous cell carcinoma associated with EGFR-TKI use remains poorly reported. We report a case of stage IV lung adenocarcinoma with EGFR mutations that converted to squamous cell carcinoma due to long-term administration of EGFR-TKIs. This report strengthens histological evolution as a source of acquired drug resistance.

The potential application of branch-PCR assembled PTEN gene nanovector in lung cancer gene therapy

Gene therapy offers an alternative and promising avenue to lung cancer treatment. Here, we used dibenzocyclooctyne (DBCO)-branched primers to construct a kind of PTEN gene nanovector (NP-PTEN) through branch-PCR. NP-PTEN showed the nanoscale structure with the biocompatible size (84.7 ± 11.2 nm) and retained the improved serum stability compared to linear DNA. When transfected into NCI-H1299 cancer cells, NP-PTEN could overexpress PTEN protein to restore PTEN function through the deactivation of PI3K-AKT-mTOR signaling pathway to inhibit cell proliferation and induce cell apoptosis. The apoptosis rate of NCI-H1299 cancer cells could reach up to 54.5% ± 4.6% when the transfection concentration of NP-PTEN was 4.0 μg/mL. In mice bearing NCI-H1299 tumor xenograft intratumorally administrated with NP-PTEN, the average tumor volume and tumor weight was separately reduced by 61.7% and 63.9% compared with the PBS group on the 18 th day of administration. The anticancer efficacy of NP-PTEN in NCI-H1299 tumor xenograft suggested the promising therapeutic potential of this branch-PCR assembled PTEN gene nanovectors in lung cancer gene therapy and also provided more opportunities to introduce two or more tumor suppressor genes as the all-in-one gene nanovectors for multiple gene-based cancer gene therapy.

Integrating circulating-free DNA (cfDNA) analysis into clinical practice: opportunities and challenges

In the current era of precision medicine, the identification of genomic alterations has revolutionised the management of patients with solid tumours. Recent advances in the detection and characterisation of circulating tumour DNA (ctDNA) have enabled the integration of liquid biopsy into clinical practice for molecular profiling. ctDNA has also emerged as a promising biomarker for prognostication, monitoring disease response, detection of minimal residual disease and early diagnosis. In this Review, we discuss current and future clinical applications of ctDNA primarily in non-small cell lung cancer in addition to other solid tumours.

Regulation of neuroendocrine plasticity by the RNA-binding protein ZFP36L1

Some small cell lung cancers (SCLCs) are highly sensitive to inhibitors of the histone demethylase LSD1. LSD1 inhibitors are thought to induce their anti-proliferative effects by blocking neuroendocrine differentiation, but the mechanisms by which LSD1 controls the SCLC neuroendocrine phenotype are not well understood. To identify genes required for LSD1 inhibitor sensitivity in SCLC, we performed a positive selection genome-wide CRISPR/Cas9 loss of function screen and found that ZFP36L1, an mRNA-binding protein that destabilizes mRNAs, is required for LSD1 inhibitor sensitivity. LSD1 binds and represses ZFP36L1 and upon LSD1 inhibition, ZFP36L1 expression is restored, which is sufficient to block the SCLC neuroendocrine differentiation phenotype and induce a non-neuroendocrine "inflammatory" phenotype. Mechanistically, ZFP36L1 binds and destabilizes SOX2 and INSM1 mRNAs, two transcription factors that are required for SCLC neuroendocrine differentiation. This work identifies ZFP36L1 as an LSD1 target gene that controls the SCLC neuroendocrine phenotype and demonstrates that modulating mRNA stability of lineage transcription factors controls neuroendocrine to non-neuroendocrine plasticity.

EGFR-mutant NSCLC: monitoring the molecular evolution of tumors in 2022

INTRODUCTION

Epidermal growth factor receptor (EGFR) activating mutations define a subset of advanced, metastatic non-small cell lung cancers (NSCLCs), that was historically identified along with the clinical development of specific EGFR tyrosine kinase inhibitors (TKIs), opening the era of precision medicine in thoracic oncology.

AREAS COVERED

Progression after EGFR TKIs is a major challenge for patients, as it occurs ineluctably along with disease evolution. Osimertinib is the current standard-of-care for the first-line treatment of EGFR-mutant NSCLC. Mechanisms of resistance to osimertinib are challenging to identify, and are dominated by MET pathway activation, and acquired EGFR mutations.

EXPERT OPINION

The current vision for clinical practice in patients with EGFR-mutant NSCLC developing disease progression after osimertinib includes the following 5 steps:- continuation of osimertinib beyond progression, and local treatment of oligoprogressive disease, - comprehensive genomic profiling based on tissue rebiopsy of progressing sites, - access to new treatment agents through clinical trials, - molecular tumor board to discuss the off-label use of targeted agents, depending on the availability of drugs and/or expanded access programs - chemotherapy may be the best choice, based on combination of platinum-based regimen and antiangiogenic agents and possibly immune checkpoint inhibitors.

Analysis of neuroendocrine clones in NSCLCs using an immuno-guided laser-capture microdissection-based approach

Clonal evolution and lineage plasticity are key contributors to tumor heterogeneity and response to treatment in cancer. However, capturing signal transduction events in coexisting clones remains challenging from a technical perspective. In this study, we developed and tested a signal-transduction-based workflow to isolate and profile coexisting clones within a complex cellular system like non-small cell lung cancers (NSCLCs). Cooccurring clones were isolated under immunohistochemical guidance using laser-capture microdissection, and cell signaling activation portraits were measured using the reverse-phase protein microarray. To increase the translational potential of this work and capture druggable vulnerabilities within different clones, we measured expression/activation of a panel of key drug targets and downstream substrates of FDA-approved or investigational agents. We isolated intermixed clones, including poorly represented ones (<5% of cells), within the tumor microecology and identified molecular characteristics uniquely attributable to cancer cells that undergo lineage plasticity and neuroendocrine transdifferentiation in NSCLCs.

Third-generation EGFR and ALK inhibitors: mechanisms of resistance and management

The discoveries of EGFR mutations and ALK rearrangements as actionable oncogenic drivers in non-small-cell lung cancer (NSCLC) has propelled a biomarker-directed treatment paradigm for patients with advanced-stage disease. Numerous EGFR and ALK tyrosine kinase inhibitors (TKIs) with demonstrated efficacy in patients with EGFR-mutant and ALK-rearranged NSCLCs have been developed, culminating in the availability of the highly effective third-generation TKIs osimertinib and lorlatinib, respectively. Despite their marked efficacy, resistance to these agents remains an unsolved fundamental challenge. Both 'on-target' mechanisms (largely mediated by acquired resistance mutations in the kinase domains of EGFR or ALK) and 'off-target' mechanisms of resistance (mediated by non-target kinase alterations such as bypass signalling activation or phenotypic transformation) have been identified in patients with disease progression on osimertinib or lorlatinib. A growing understanding of the biology and spectrum of these mechanisms of resistance has already begun to inform the development of more effective therapeutic strategies. In this Review, we discuss the development of third-generation EGFR and ALK inhibitors, predominant mechanisms of resistance, and approaches to tackling resistance in the clinic, ranging from novel fourth-generation TKIs to combination regimens and other investigational therapies.

Cholesterol homeostasis and cancer: a new perspective on the low-density lipoprotein receptor

BACKGROUND

Disturbance of cholesterol homeostasis is considered as one of the manifestations of cancer. Cholesterol plays an essential role in the pleiotropic functions of cancer cells, including mediating membrane trafficking, intracellular signal transduction, and production of hormones and steroids. As a single transmembrane receptor, the low-density lipoprotein receptor (LDLR) can participate in intracellular cholesterol uptake and regulate cholesterol homeostasis. It has recently been found that LDLR is aberrantly expressed in a broad range of cancers, including colon cancer, prostate cancer, lung cancer, breast cancer and liver cancer. LDLR has also been found to be involved in various signaling pathways, such as the MAPK, NF-κB and PI3K/Akt signaling pathways, which affect cancer cells and their surrounding microenvironment. Moreover, LDLR may serve as an independent prognostic factor for lung cancer, breast cancer and pancreatic cancer, and is closely related to the survival of cancer patients. However, the role of LDLR in some cancers, such as prostate cancer, remains controversial. This may be due to the lack of normal feedback regulation of LDLR expression in cancer cells and the severe imbalance between LDLR-mediated cholesterol uptake and de novo biosynthesis of cholesterol.

CONCLUSIONS

The imbalance of cholesterol homeostasis caused by abnormal LDLR expression provides new therapeutic opportunities for cancer. LDLR interferes with the occurrence and development of cancer by modulating cholesterol homeostasis and may become a novel target for the development of anti-cancer drugs. Herein, we systematically review the contribution of LDLR to cancer progression, especially its dysregulation and underlying mechanism in various malignancies. Besides, potential targeting and immunotherapeutic options are proposed.

Postoperative Long-Term Outcomes and Independent Risk Factors of Non-Small-Cell Lung Cancer Patients With Propofol versus Sevoflurane Anesthesia: A Retrospective Cohort Study

Background: Existing studies have shown that the relationship between anesthetic agents and non-small-cell lung cancer (NSCLC) prognosis remains controversial. Therefore, this retrospective cohort study was designed to investigate the effects of propofol or sevoflurane anesthesia on the long-term oncologic outcomes of NSCLC patients.

Methods: We identified 1,778 eligible patients (propofol-based total intravenous anesthesia (TIVA) group, n = 686; sevoflurane-based inhalation anesthesia (INHA) group, n = 1,092) out of 2,388 patients undergoing elective NSCLC surgery from June 2013 to June 2016 in the Harbin Medical University Cancer Hospital. The primary endpoints were five-year overall survival and recurrence-free survival. The secondary endpoints were independent risk factors of cancer recurrence or all-cause mortality. The data were analyzed with propensity score matching, Kaplan–Meier survival, and Cox multivariate analyses as appropriate.

Results: After propensity score matching, there were 672 patients in each group. The median follow-up period was 69 months (interquartile range: 68–70 months) for all patients. Five-year overall survival was 75.7% (95% confidence interval (CI) 72.4–79.1) in the TIVA group and 71.8% (68.4–75.4) in the INHA group (p = 0.160) (hazard ratio (HR), 0.86; 95% CI, 0.70–1.06; p = 0.158), and five-year recurrence-free survival was 68.5% (65.0–72.2) and 62.7% (59.1–66.5 (p = 0.108) (HR, 0.90; 95% CI, 0.75–1.08; p = 0.253), respectively. Subgroup analyses showed there were no significant difference in the overall survival or recurrence-free survival between the two groups in each TNM stage of NSCLC. The independent risk factors included age ≥60 years, male, blood transfusion, segmental/wedge resection and pneumonectomy, thoracotomy, postoperative complications, lung adenocarcinoma, TNM stages, high CEA and CYFRA211 levels, and postoperative radiotherapy.

Conclusions: Our data indicated no difference between the propofol-based TIVA and sevoflurane-based INHA in terms of five-year overall survival and recurrence-free survival after NSCLC surgery.

Emerging strategies to overcome resistance to third-generation EGFR inhibitors

Epidermal growth factor receptor (EGFR), the receptor for members of the epidermal growth factor family, regulates cell proliferation and signal transduction; moreover, EGFR is related to the inhibition of tumor cell proliferation, angiogenesis, invasion, metastasis, and apoptosis. Therefore, EGFR has become an important target for the treatment of cancer, including non-small cell lung cancer, head and neck cancer, breast cancer, glioma, cervical cancer, and bladder cancer. First- to third-generation EGFR inhibitors have shown considerable efficacy and have significantly improved disease prognosis. However, most patients develop drug resistance after treatment. The challenge of overcoming intrinsic and acquired resistance in primary and recurrent cancer mediated by EGFR mutations is thus driving the search for alternative strategies in the design of new therapeutic agents. In view of resistance to third-generation inhibitors, understanding the intricate mechanisms of resistance will offer insight for the development of more advanced targeted therapies. In this review, we discuss the molecular mechanisms of resistance to third-generation EGFR inhibitors and review recent strategies for overcoming resistance, new challenges, and future development directions.

Histological Transformation after Acquired Resistance to the Third-Generation EGFR-TKI in Patients with Advanced EGFR-Mutant Lung Adenocarcinoma

Background and Objectives: Third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) is one of the standard-of-care therapies in patients with EGFR-mutant lung adenocarcinoma; however, acquired resistance inevitably developed. Despite the proposition of histological transformation being one of the resistance mechanisms, its incidence and influence on outcome remain unclear. Materials and Methods: This was a retrospective study conducted at Taichung Veterans General Hospital on patients with advanced EGFR-mutant lung adenocarcinoma receiving the third-generation EGFR-TKI. Only patients receiving rebiopsy were included in the analysis. Results: A total of 55 patients were studied. Eight patients (14.5%) showed histological transformation, including three small cell carcinoma, three squamous cell carcinoma, one large cell neuroendocrine carcinoma, and one with a mixture of adenocarcinoma and squamous cell carcinoma components. The median treatment duration of the third-generation EGFR-TKI before rebiopsy was numerically longer in patients with histological transformation than those without (16.0 vs. 10.9 months). Both the overall survival time from the start of third-generation EGFR-TKI initiation (30.8 vs. 41.2 months) and from rebiopsy (6.6 vs. 12.9 months) to mortality were numerically shorter amongst the transformed population. All patients in the transformed group did not respond to the next line of systemic treatment. One patient with histological transformation receiving local treatment for the metastatic site had a longer overall survival. Conclusions: Repeating biopsy to identify histological transformation should be considered in patients with progression to the third-generation EGFR-TKI. Histological transformations could contribute to the acquired resistance with the implication of a worse prognosis. Further studies are needed to determine the optimal therapy for these patients.

Heterogeneity or transformation? A whack-a-mole case of EGFR-mutant lung adenocarcinoma and small cell carcinoma: A case report

Histological transformation from adenocarcinoma to small cell lung cancer (SCLC) occurs ~10% after acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors. Transformed SCLC generally responds well to chemotherapy regimens for SCLC such as platinum plus etoposide. After the response, histological nature and clinical course could be complicated by possible heterogeneity or transformation. Therefore, monitoring rebiospy is desirable to seize its histological nature at that moment. We report a case of EGFR-mutated adenocarcinoma, where histological transformations from adenocarcinoma and SCLC alternated. In this case, first rebiopsy after gefitinib revealed adenocarcinoma, but second rebiopsy after osimertinib identified SCLC transformation. After failure of platinum plus etoposide, adenocarcinoma-induced leptomeningeal metastases were controlled by osimertinib reintroduction. Optimal therapies could be provided according to the result of monitoring rebiopsy.

Targeting mitochondrial one-carbon enzyme MTHFD2 together with pemetrexed confers therapeutic advantages in lung adenocarcinoma

Metabolic remodeling is the fundamental molecular feature of malignant tumors. Cancer cells require sufficient energy supplies supporting their high proliferative rate. MTHFD2, a mitochondrial one-carbon metabolic enzyme, is dysregulated in several malignancies and may serve as a promising therapeutic candidate in cancer treatment. Here, our data confirmed that MTHFD2 gene and protein was upregulated in the cancerous tissues of LUAD patients and was correlated with a poor survival in LUAD. MTHFD2 was involved in lung cancer cell proliferation, migration, and apoptosis by mediating its downstream molecules, such as DNA helicases (MCM4 and MCM7), as well as ZEB1, Vimentin and SNAI1, which contributed to tumor cell growth and epithelial-to-mesenchymal transition (EMT) process. Moreover, we identified that miRNA-99a-3p appeared to be an upstream mediator directly regulating MTHFD2 and MCM4 expression. Moreover, specific inhibition of MTHFD2 functions by siRNA or a chemical compound, improved anti-tumor sensitivities induced by pemetrexed in LUAD. Taken together, our study revealed the underlying molecular mechanisms of MTHFD2 in regulating cell proliferation and identified a novel therapeutic strategy improving the treatment efficacies in LUAD.

Lung Cancer Prediction Using Robust Machine Learning and Image Enhancement Methods on Extracted Gray-Level Co-Occurrence Matrix Features

In the present era, cancer is the leading cause of demise in both men and women worldwide, with low survival rates due to inefficient diagnostic techniques. Recently, researchers have been devising methods to improve prediction performance. In medical image processing, image enhancement can further improve prediction performance. This study aimed to improve lung cancer image quality by utilizing and employing various image enhancement methods, such as image adjustment, gamma correction, contrast stretching, thresholding, and histogram equalization methods. We extracted the gray-level co-occurrence matrix (GLCM) features on enhancement images, and applied and optimized vigorous machine learning classification algorithms, such as the decision tree (DT), naïve Bayes, support vector machine (SVM) with Gaussian, radial base function (RBF), and polynomial. Without the image enhancement method, the highest performance was obtained using SVM, polynomial, and RBF, with accuracy of (99.89%). The image enhancement methods, such as image adjustment, contrast stretching at threshold (0.02, 0.98), and gamma correction at gamma value of 0.9, improved the prediction performance of our analysis on 945 images provided by the Lung Cancer Alliance MRI dataset, which yielded 100% accuracy and 1.00 of AUC using SVM, RBF, and polynomial kernels. The results revealed that the proposed methodology can be very helpful to improve the lung cancer prediction for further diagnosis and prognosis by expert radiologists to decrease the mortality rate.

circCCT3 Enhances Invasion and Epithelial-Mesenchymal Transition (EMT) of Non-Small-Cell Lung Cancer (NSCLC) via the miR-107/Wnt/FGF7 Axis

Background. CircRNAs play a role in a variety of biological processes, including tumorigenesis. circCCT3 has been shown to regulate cancer initiation and progression. Unfortunately, whether circCCT3 is involved in non-small-cell lung cancer (NSCLC) metastasis remains unclear. Methods. Our study utilized RT-qPCR to examine gene expression levels. A transwell assay was used to measure invasion ability of cells. Starbase software and TargetScan software were used to predict target genes. Results. circCCT3 knockdown attenuated invasion and epithelial-mesenchymal transition (EMT) of A549 and Calu-1 cells. miR-107 mimics could rescue circCCT3-induced invasion and EMT. Next, miR-107 mimics and circCCT3 knockdown suppressed Wnt3a and FGF7 expression. An miR-107 inhibitor promoted Wnt3a and FGF7 expressions. Finally, FGF7 greatly restored miR-107-inhibited invasion and EMT of A549 cells. Conclusion. Here, we reveal a molecular mechanism circCCT3/miR-107/Wnt/FGF7 responsible for NSCLC metastasis.

Manganese-Based Prussian Blue Nanocatalysts Suppress Non-Small Cell Lung Cancer Growth and Metastasis via Photothermal and Chemodynamic Therapy

Based on the safety of prussian blue (PB) in biomedical application, we prepared manganese-based prussian blue (MnPB) nanocatalysts to achieve enhanced photothermal therapy and chemodynamic therapy. And we conducted a series of experiments to explore the therapeutic effects of MnPB nanoparticles (NPs) on non-small cell lung cancer (NSCLC) in vivo and in vitro. For in vitro experiments, the MnPB NPs suppressed growth of A549 cells by reactive oxygen species upregulation and near-infrared irradiation. Moreover, the MnPB NPs could inhibit lung cancer metastasis through downregulating the matrix metalloproteinase (MMP)-2 and MMP-9 expression in A549 cells. And for in vivo experiments, the MnPB NPs inhibited the growth of xenografted tumor effectively and were biologically safe. Meanwhile, Mn²⁺ as a T1-weighted agent could realize magnetic resonance imaging-guided diagnosis and treatment. To sum up, the results in this study clearly demonstrated that the MnPB NPs had remarkable effects for inhibiting the growth and metastasis of NSCLC and might serve as a promising multifunctional nanoplatform for NSCLC treatment.

A Real-World Systematic Analysis of Driver Mutations' Prevalence in Early- and Advanced-Stage NSCLC: Implications for Targeted Therapies in the Adjuvant Setting

Simple Summary

The development of oncogene-targeted drugs has radically changed the course of non small cell lung carcinoma (NSCLC) in the advanced stage. Recently, the ADAURA trial demonstrated the efficacy of Osimertinib also in the adjuvant setting of EGFR-mutated NSCLC. This raises the question regarding whether the same paradigm applies also to currently approved drugs directed against non-EGFR NSCLC drivers. Herein we compared actionable genomic alterations in early- and advanced-stage NSCLC in 1961 unselected single-institution cases analyzed by routine molecular diagnostics procedures. Our data add significantly to the currently limited real-world data on actionable mutations in surgically resectable NSCLC. Our finding that distinct NSCLC genomic drivers are mutated at similar frequencies in early- and advanced-stage tumors implies that the relative biological potency of currently actionable NSCLC genomic drivers is conserved throughout clinical evolution and supports the hypothesis that genotype-matched therapies are likely to provide significant benefit in an adjuvant setting

Abstract

The approval of osimertinib for adjuvant treatment of stage I–II–III EGFR-mutated NSCLC (early stage) represents a paradigm shift, raising the question of whether other genotype-matched therapeutics approved for advanced-stage NSCLC can also provide clinical benefit in the adjuvant setting. However, there is a paucity of real-world data on the prevalence of actionable genomic alterations (GAs) in early-stage NSCLC. We used next-generation sequencing, complemented by immunohistochemistry and fluorescence in situ hybridization, to screen our single-institution cohort of 1961 NSCLC consecutive cases for actionable molecular targets. The prevalence of actionable GAs was comparable in early versus advanced-stage NSCLC, the only exception being KRAS mutations (more frequent in early-stage cases). Consistent with advanced-stage tumors being more aggressive, co-occurrence of TP53 and EGFR GAs as well as copy number gains were less frequent in early-stage tumors. EGFR mutations and high expression of PD-L1 were inversely associated, whereas KRAS mutations and high PD-L1 reactivity showed positive association. Recapitulating advanced-stage tumors, early-stage NSCLC had the highest share of EGFR mutations in lepidic and acinar subtypes. Resected lepidic tumors contained the highest proportion of the KRAS G12C actionable variant. These results, obtained with routine diagnostic technologies in an unselected clinical setting, provide a significant addition of real-world data in early-stage NSCLC.

Expression of Zyxin in Non-Small Cell Lung Cancer-A Preliminary Study

Background: The potential involvement of zyxin (ZYX) in carcinogenesis has been investigated in many cancer types. However, there are a limited number of studies on the role of ZYX in the progression of non-small cell lung cancer (NSCLC). Since lung cancer is one of the most frequently diagnosed carcinomas, the aim of our study was to determine the localization and expression levels of ZYX in NSCLC and to correlate the results with the clinicopathological data. Materials and Methods: The expression of ZYX was assessed in NSCLC cases and in cell lines representing this tumor type. Levels of ZYX were determined in the clinical material using immunohistochemistry (IHC) and Western Blot. Real-time PCR was used to assess ZYX mRNA levels. The expression of ZYX was also checked in NSCLC cell lines using real-time PCR, Western Blot, and immunofluorescence/immunocytochemistry. Results: The results showed lower levels of ZYX in NSCLC cells compared with control tissues. This trend was observed at the protein and mRNA levels. The assays on the NSCLC model also demonstrated lower levels of ZYX in cancer cells compared with control cells. Conclusions: The decreased expression of ZYX in NSCLC may indicate a suppressor role of this protein in NSCLC.

Transformation from lung adenocarcinoma to combined small cell carcinoma in pleural effusion after treatment with osimertinib

The transformation of lung adenocarcinoma to combined small cell lung cancer is a rare mechanism of acquired resistance to EGFR tyrosine kinase inhibitors. This case describes this mechanism in a pleural effusion of a young patient treated with osimertinib for 18 months.

ROS1-positive non-small cell lung cancer (NSCLC): Biology, Diagnostics, Therapeutics and Resistance

ROS1 is a proto-oncogene encoding a receptor tyrosine protein kinase (RTK), homologous to the v - Ros sequence of University of Manchester tumours virus 2(UR2) sarcoma virus, whose ligands are still being investigated. ROS1 fusion genes have been identified in various types of tumours. As an oncoprotein, it promotes cell proliferation, activation and cell cycle progression by activating downstream signalling pathways, accelerating the development and progression of non-small cell lung cancer (NSCLC). Studies have demonstrated that ROS1 inhibitors are effective in patients with ROS1-positive NSCLC and are used for first-line clinical treatment. These small molecule inhibitors provide a rational therapeutic option for the treatment of ROS1-positive patients. Inevitably, ROS1 inhibitor resistance mutations occur, leading to tumours recurrence or progression. Here, we comprehensively review the identified biological properties and Differential subcellular localization of ROS1 fusion oncoprotein promotes tumours progression. We summarize recently completed and ongoing clinical trials of the classic and new ROS1 inhibitors. More importantly, we classify the complex evolving tumours cell resistance mechanisms. This review contributes to our understanding of the biological properties of ROS1 and current therapeutic advances and resistant tumours cells, and the future directions to develop ROS1 inhibitors with durable effects.

Treatment strategy, overall survival and associated risk factors among patients with unresectable stage IIIB/IV non-small cell lung cancer in China (2015-2017): A multicentre prospective study

BACKGROUND

There are limited studies on treatment and survival analysis among patients with unresectable Stage IIIB or IV non-small cell lung cancer (NSCLC) in routine practice in China. To address this gap, we conducted a prospective observational study in a cohort of patients treated at 11 hospitals in China.

METHODS

This was a multicentre, prospective cohort study including patients with newly diagnosed unresectable Stage IIIB or IV NSCLC from June 26th, 2015 to April 28th, 2017. Patient baseline characteristics, disease characteristics, and anti-cancer treatments were obtained by medical chart review. The overall survival (OS) from the initiation of first-line treatment was analysed by the Kaplan-Meier method. Factors associated with survival were analysed by univariate and multivariate Cox regression models.

FINDINGS

Among 1324 patients enrolled with median follow-up duration of 15·0 (range: 0·0-42·1) months, 83·5% (1105/1324) of them received first-line chemotherapy of which platinum-based compounds were the dominated agents. Overall, 30·9% (409/1324) of patients received targeted therapy as 1st-line treatment including 65·0% (266/409) EGFR-TKIs and 5·1% (21/409) ALK-TKIs. Of all eligible patients, gene testing rates were 44·0% (583/1324) for EGFR mutations, 17·0% (225/1324) for EML4-ALK gene fusions, and 8·3% (110/1324) for ROS1 gene fusions. The EGFR-TKIs were administered to 63·9% (179/280) of EGFR mutated patients as first-line treatment. The overall median OS was 23·2 (95%CI 19·5-25·5) months, and patients treated at tier 1 cities had better OS than that of tier 2 cities. Also, the OS in patients with EGFR mutation was longer than those with EGFR wild type. Multivariate Cox regression models suggested that male, education below high school, tier 2 cities, smoking history, and multiple metastases were associated with poor survival.

INTERPRETATION

The gene test coverage was relatively low among the studied population, and over half of EGFR mutated patients received EGFR-TKIs, suggesting that the result of genetic tests in real-world settings may not always indicate the selection of treatment. The OS benefit observed from patients treated in tier 1 cities and those with EGFR mutation may indicate a need for broader gene test coverage, providing NSCLC patients with personalized treatment according to the results of genetic tests.

FUNDING

Roche Holding AG.TRANSLATED ABSTRACT: This translation in Chinese was submitted by the authors and we reproduce it as supplied. It has not been peer reviewed. Our editorial processes have only been applied to the original abstract in English, which should serve as reference for this manuscript.:IIIBIV(NSCLC)., ,, 11.:,, 20156262017428IIIBIVNSCLC.,.Kaplan-Meier(OS), Cox.:1324, 15.0(:0.0-42.1), 83.5%(1105/1324), ., 30.9%(409/1324), 65.0%(266/409)EGFR-TKI5.1%(21/409)ALK-TKI., EGFR,EML4-ALKROS144.0%(583/1324),17.0%(225/1324)8.3%(110/1324).63.9%(179/280)EGFREGFR-TKI.23.2 (95% 19·5-25·5) , ., EGFREGFR.Cox, ,,,.:, EGFREGFR-TKI, , .EGFR, , NSCLC.

REST Inactivation and Coexpression of ASCL1 and POU3F4 Are Necessary for the Complete Transformation of RB1/TP53-Inactivated Lung Adenocarcinoma into Neuroendocrine Carcinoma

Although recent reports have revealed the importance of the inactivation of both RB1 and TP53 in the transformation from lung adenocarcinoma into neuroendocrine carcinoma (NEC), the requirements for complete transformation into NEC have not been elucidated. To investigate alterations in the characteristics associated with the inactivation of RB1/TP53 and define the requirements for transformation into NEC cells, RB1/TP53 double-knockout A549 lung adenocarcinoma cells were established, and additional knockout of REST and transfection of ASCL1 and POU class 3 homeobox transcription factors (TFs) was conducted. More than 60 genes that are abundantly expressed in neural cells and several genes associated with epithelial-to-mesenchymal transition were up-regulated in RB1/TP53 double-knockout A549 cells. Although the expression of chromogranin A and synaptophysin was induced by additional knockout of REST (which mimics the status of most NECs), the expression of another neuroendocrine marker, CD56, and proneural TFs was not induced. However, coexpression of ASCL1 and POU3F4 in RB1/TP53/REST triple-knockout A549 cells induced the expression of not only CD56 but also other proneural TFs (NEUROD1 and insulinoma-associated 1) and induced NEC-like morphology. These findings suggest that the inactivation of RB1 and TP53 induces a state necessary for the transformation of lung adenocarcinoma into NEC and that further inactivation of REST and coexpression of ASCL1 and POU3F4 are the triggers for complete transformation into NEC.

Tumor-Derived Exosomes Regulate Apoptosis of CD45+EpCAM+ Cells in Lung Cancer

Lung cancer has the highest mortality rate among human cancers, and the majority of deaths result from metastatic spread. The tumor microenvironment plays an important role in suppressing the immune surveillance and elimination of tumor cells. A few studies have reported the presence of CD45⁺EpCAM⁺ double-positive cells in cancer, but the underlying mechanism remains unclear with respect to how these cells originate and their function in cancer biology. In this study, we analyzed 25 lung tumor samples. We confirmed the presence of CD45⁺EpCAM⁺ cells in lung cancer, and these cells exhibited higher apoptosis than CD45⁺EpCAM⁻ cells. Using co-culture of lung cancer cell-derived exosomes with healthy donor peripheral blood mononuclear cells, we recapitulated CD45⁺EpCAM⁺ cell formation and increased apoptosis that occurs in patients with primary lung cancer. Further analysis suggested that microRNAs in lung cancer cell-derived exosomes may alter the gene expression profile of CD45⁺EpCAM⁺ cells, resulting in elevated TP53 expression and increased apoptosis. To our knowledge, this is the first report of cancer cell-derived exosomes that can inhibit the immune system by promoting immune cell apoptosis.

Circ_0001998 Regulates the Proliferation, Invasion, and Apoptosis of Lung Adenocarcinoma via Sponging miR-145

Circular RNA (circRNA) is considered an important regulator of cancer. Circ_0001998 is a newly discovered circRNA and its role in lung adenocarcinoma (LUAD) remains obscure and requires further study. The expression levels of circ_0001998 and miR-145 in LUAD were predicted by bioinformatics analysis and then verified by qRT-PCR in the LUAD cell lines. CCK-8, clone formation, EdU assay, and flow cytometry were applied to determine the effects of silencing circ_0001998 on the viability, proliferation, and apoptosis of LUAD cells. The target relationship between circ_0001998 and miR-145 was predicted by bioinformatics analysis and verified by a luciferase activity experiment. The effect of circ_0001998/miR-145 axis on the viability, proliferation, and apoptosis of LUAD cells was verified by the rescue experiment. Circ_0001998 was upregulated in LUAD, and silencing circ_0001998 suppressed viability, proliferation, and invasion of LUAD cells. The target gene of circ_0001998, miR-145, was downregulated in LUAD, and the low expression of miR-145 indicated a poor prognosis. The effect of silencing circ_0001998 on the biological function of LUAD cells was reversed by the miR-145 inhibitor. Circ_0001998 regulates the proliferation, invasion, and apoptosis of LUAD via sponging miR-145.

Dynamic monitoring serum tumor markers to predict molecular features of EGFR-mutated lung cancer during targeted therapy

To reveal the correlation of dynamic serum tumor markers (STMs) and molecular features of epidermal growth factor receptor‐mutated (EGFR‐mutated) lung cancer during targeted therapy, we retrospectively reviewed 303 lung cancer patients who underwent dynamic STM tests [neuron‐specific enolase (NSE), carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), carbohydrate antigen 153 (CA153), the soluble fragment of cytokeratin 19 (CYFRA21‐1), and squamous cell carcinoma antigen (SCC)] and circulating tumor DNA (ctDNA) testing with a panel covering 168 genes. At baseline, patients with EGFR mutation trended to have abnormal CEA, abnormal CA153, and normal SCC levels. Additionally, patients with Thr790Met (T790M) mutation were more likely to have abnormal CEA levels than patients without T790M mutation. Among patients with secondary resistance to EGFR tyrosine kinase inhibitors (TKI), the dynamic STMs showed a descending trend in the responsive stage and a rising trend in the resistant stage. However, the changing slopes differed between T790M subgroup and the non‐T790M subgroup in individual STMs. Our study demonstrated that the combination of baseline levels and variations of STMs (including the responsive stage and resistant stage) can be suggestive of secondary EGFR‐T790M mutation [area under the curve (AUC) = 0.897] and that changing trends of STMs (within 8 weeks after initiating the TKI therapy) can be potential predictors for the clearance of EGFR ctDNA [AUC = 0.871]. In conclusion, dynamic monitoring STMs can help to predict the molecular features of EGFR‐mutated lung cancer during targeted therapy.

The functional roles of the circRNA/Wnt axis in cancer

CircRNAs, covalently closed noncoding RNAs, are widely expressed in a wide range of species ranging from viruses to plants to mammals. CircRNAs were enriched in the Wnt pathway. Aberrant Wnt pathway activation is involved in the development of various types of cancers. Accumulating evidence indicates that the circRNA/Wnt axis modulates the expression of cancer-associated genes and then regulates cancer progression. Wnt pathway-related circRNA expression is obviously associated with many clinical characteristics. CircRNAs could regulate cell biological functions by interacting with the Wnt pathway. Moreover, Wnt pathway-related circRNAs are promising potential biomarkers for cancer diagnosis, prognosis evaluation, and treatment. In our review, we summarized the recent research progress on the role and clinical application of Wnt pathway-related circRNAs in tumorigenesis and progression.

Detection of acquired TERT amplification in addition to predisposing p53 and Rb pathways alterations in EGFR-mutant lung adenocarcinomas transformed into small-cell lung cancers

INTRODUCTION

Among the different mechanisms of acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) reported in EGFR-mutated lung adenocarcinoma (EGFR-LUAD) patients, histological transformation into small cell carcinoma (SCLC) occurs in 3-14% of resistant cases, regardless of the generation of EGFR-TKI. In recent studies, bi-allelic inactivation of TP53 and RB1 has been identified in a vast majority of transformed SCLCs. However, the molecular mechanisms driving this histologic transformation remain largely unknown, mainly due to the rarity of samples.

PATIENTS AND METHODS

Out of an initial cohort of 64 patients, tumor tissues of adequate quality and quantity for whole exome sequencing (WES) analysis were available for nine tumors for six patients: paired pre- and post-SCLC transformation samples for three Patients and post-SCLC transformation samples for three other patients.

RESULTS

Mutational analyses showed concurrent TP53 mutations and Rb pathway alterations in five of the six patients analyzed, confirming their suggested role as predisposing genetic alterations to SCLC transformation. In addition, TERT amplification was detected in four of the six patients and found to be an event acquired during SCLC transformation. Clonal history evolution analyses from the paired LUAD/SCLC samples showed different evolution patterns. In two patients, a large proportion of mutations were present in the most recent common ancestor cell of the initial LUAD and the transformed SCLC clones, whereas in the third patient, few clonal mutations were common between the LUAD and SCLC samples and the ancestor clone that lead to SCLC was present at low frequency in the initial LUAD.

CONCLUSION

Despite varied clinical presentations and clonal history evolution patterns, in addition to p53 and Rb pathways alterations, TERT amplification emerged as another common genetic mechanism of EGFR-LUAD to SCLC transformation in our cohort, and could represent a candidate therapeutic target in this subset of SCLC tumors.

Epigenetic Alterations and Inflammation as Emerging Use for the Advancement of Treatment in Non-Small Cell Lung Cancer

Lung cancer remains one of the most common malignancies in the world. Nowadays, the most common lung cancer is non-small cell lung cancer (NSCLC), namely, adenocarcinoma, squamous cell carcinoma, and large cell lung carcinoma. Epigenetic alterations that refer to DNA methylation, histone modifications, and noncoding RNA expression, are now suggested to drive the genesis and development of NSCLC. Additionally, inflammation-related tumorigenesis also plays a vital role in cancer research and efforts have been attempted to reverse such condition. During the occurrence and development of inflammatory diseases, the immune component of inflammation may cause epigenetic changes, but it is not always certain whether the immune component itself or the stimulated host cells cause epigenetic changes. Moreover, the links between epigenetic alterations and cancer-related inflammation and their influences on the human cancer are not clear so far. Therefore, the connection between epigenetic drivers, inflammation, and NSCLC will be summarized. Investigation on such topic is most likely to shed light on the molecular and immunological mechanisms of epigenetic and inflammatory factors and promote the application of epigenetics in the innovative diagnostic and therapeutic strategies for NSCLC.

Observational study of rebiopsy in EGFR-TKI-resistant patients with EGFR mutation-positive advanced NSCLC

The identification of acquired resistance mutations has been essential in non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) active mutations. Rebiopsy plays a pivotal role in selecting the optimal treatment for patients who develop resistance to initial EGFR-tyrosine kinase inhibitors (EGFR-TKIs). This multicenter, observational study was conducted to investigate the details of rebiopsy in Japanese clinical practice. The primary endpoints were the implementation rate of rebiopsy and the concordance rate for T790M mutation detection between histological and cytological specimens using the cobas EGFR Mutation Test, version 2. One hundred ninety-four patients with EGFR-mutant NSCLC were enrolled, and 120 patients developed acquired resistance to EGFR-TKIs. The median age was 68 years (range 20-87), and 52.5% of the patients were women. Rebiopsy was performed in 109 patients, and the implementation rate of rebiopsy was 90.8%. The success rates of rebiopsy in the total, histology, cytology and liquid biopsy populations were 67.9%, 81.3%, 66.7% and 43.8%, respectively. The positive percent agreement and the negative percent agreement in the detection of the T790M mutation between the histological and cytological specimens were both 90.9%. Obtaining histological or cytological tissue samples at rebiopsy may contribute to improving the detection rate of the T790M mutation (trial registration number: UMIN000026019).

Morphologic-Molecular Transformation of Oncogene Addicted Non-Small Cell Lung Cancer

Patients with non-small cell lung cancer, especially adenocarcinomas, harbour at least one oncogenic driver mutation that can potentially be a target for therapy. Treatments of these oncogene-addicted tumours, such as the use of tyrosine kinase inhibitors (TKIs) of mutated epidermal growth factor receptor, have dramatically improved the outcome of patients. However, some patients may acquire resistance to treatment early on after starting a targeted therapy. Transformations to other histotypes-small cell lung carcinoma, large cell neuroendocrine carcinoma, squamous cell carcinoma, and sarcomatoid carcinoma-have been increasingly recognised as important mechanisms of resistance and are increasingly becoming a topic of interest for all specialists involved in the diagnosis, management, and care of these patients. This article, after examining the most used TKI agents and their main biological activities, discusses histological and molecular transformations with an up-to-date review of all previous cases published in the field. Liquid biopsy and future research directions are also briefly discussed to offer the reader a complete and up-to-date overview of the topic.

KRAS: A Druggable Target in Colon Cancer Patients

Mutations in KRAS are among the most frequent aberrations in cancer, including colon cancer. KRAS direct targeting is daunting due to KRAS protein resistance to small molecule inhibition. Moreover, its elevated affinity to cellular guanosine triphosphate (GTP) has made the design of specific drugs challenging. Indeed, KRAS was considered ‘undruggable’. KRASG12C is the most commonly mutated variant of KRAS in non-small cell lung cancer. Currently, the achievements obtained with covalent inhibitors of this variant have given the possibility to assess the best therapeutic approach to KRAS-driven tumors. Mutation-related biochemical assets and the tissue of origin are expected to influence responses to treatment. Further attempts to obtain mutant-specific KRAS (KRASG12C) switch-II covalent inhibitors are ongoing and the results are promising. Drugs targeted to block KRAS effector pathways could be combined with direct KRAS inhibitors, immunotherapy or T cell-targeting approaches in KRAS-mutant tumors. The development of valuable combination regimens will be essential against potential mechanisms of resistance that may arise during treatment.

Non-Invasive Measurement Using Deep Learning Algorithm Based on Multi-Source Features Fusion to Predict PD-L1 Expression and Survival in NSCLC

Background

Programmed death-ligand 1 (PD-L1) assessment of lung cancer in immunohistochemical assays was only approved diagnostic biomarker for immunotherapy. But the tumor proportion score (TPS) of PD-L1 was challenging owing to invasive sampling and intertumoral heterogeneity. There was a strong demand for the development of an artificial intelligence (AI) system to measure PD-L1 expression signature (ES) non-invasively.

Methods

We developed an AI system using deep learning (DL), radiomics and combination models based on computed tomography (CT) images of 1,135 non-small cell lung cancer (NSCLC) patients with PD-L1 status. The deep learning feature was obtained through a 3D ResNet as the feature map extractor and the specialized classifier was constructed for the prediction and evaluation tasks. Then, a Cox proportional-hazards model combined with clinical factors and PD-L1 ES was utilized to evaluate prognosis in survival cohort.

Results

The combination model achieved a robust high-performance with area under the receiver operating characteristic curves (AUCs) of 0.950 (95% CI, 0.938-0.960), 0.934 (95% CI, 0.906-0.964), and 0.946 (95% CI, 0.933-0.958), for predicting PD-L1ES <1%, 1-49%, and ≥50% in validation cohort, respectively. Additionally, when combination model was trained on multi-source features the performance of overall survival evaluation (C-index: 0.89) could be superior compared to these of the clinical model alone (C-index: 0.86).

Conclusion

A non-invasive measurement using deep learning was proposed to access PD-L1 expression and survival outcomes of NSCLC. This study also indicated that deep learning model combined with clinical characteristics improved prediction capabilities, which would assist physicians in making rapid decision on clinical treatment options.

Identification of Prognostic Markers of N6-Methylandenosine-Related Noncoding RNAs in Non-Small-Cell Lung Cancer

Background

Non-small-cell lung cancer (NSCLC) is a major type of lung carcinoma that threatens the health and life of humans worldwide. We aimed to establish an n6-methyladenosine (m6A)-relevant ncRNA model to effectively evaluate the outcome of patients.

Methods

m6A-Related ncRNAs (lncRNA/miRNA) were acquired from the UCSC Xena database. Pearson's correlation analysis among 21 m6A regulatory factors and ncRNAs were implemented to explore m6A-relevant ncRNAs. Weighted gene co-expression network analysis (WGCNA) identified hub modules of gene associated with prognosis of NSCLC patients. Univariate Cox regression analysis identified 80 m6A-related ncRNAs. Least absolute shrinkage and selector operation (LASSO) filtered out redundant factors and established a risk score model (m6A-NSCLC) in the TCGA training data set. Validation of prognostic ability was performed using testing data sets from the TCGA database. We also conducted a correlation analysis among the risk score and different clinical traits. Both univariate and multivariate Cox analyses were combined to verify prognostic factors which have independent value, and a nomogram on the basis of m6A-NSCLC risk scores and clinical traits was constructed to assess the prognosis of patients. In addition, we screened differentially expressed genes (DEGs) based on different risk scores and performed enrichment analysis. Finally, 21 m6A regulators were detected to be differentially expressed between two risk groups.

Results

An m6A-NSCLC risk model with 18 ncRNAs was constructed. By comparison with low-risk patients, high-risk score patients had poor prognosis. The distribution of risk score in the tumor size and extent (T), number of near lymph nodes (N), clinical stage, sex, and tumor types was significantly different. The risk score could act as an independent prognostic factor with the nomogram assessing overall survival in NSCLC. DEGs inherent to cell movement and immune regulation were involved in NSCLC development. Furthermore, 18 of 21 m6A regulators were differentially expressed, implying their correlation to survival prognosis.

Conclusion

The m6A-NSCLC could be effectively utilized for evaluation of prognosis of patients.

The impact of CCR8+ regulatory T cells on cytotoxic T cell function in human lung cancer

Regulatory T cells (Tregs) suppress the host immune response and maintain immune homeostasis. Tregs also promote cancer progression and are involved in resistance to immune checkpoint inhibitor treatments. Recent studies identified selective CCR8 expression on tumor-infiltrating Tregs; CCR8+ Tregs have been indicated as a possible new target of cancer immunotherapy. Here, we investigated the features of CCR8+ Tregs in lung cancer patients. CCR8+ Tregs were highly activated and infiltration of CCR8+ Tregs in tumors was associated with poor prognosis in lung cancer patients. We also investigated their immune suppressive function, especially the influence on cytotoxic T lymphocyte cell function. The Cancer Genome Atlas analysis revealed that CD8 T cell activities were suppressed in high CCR8-expressing tumors. Additionally, depletion of CCR8+ cells enhanced CD8 T cell function in an ex vivo culture of lung tumor-infiltrating cells. Moreover, CCR8+ Tregs, but not CCR8− Tregs, induced from human PBMCs markedly suppressed CD8 T cell cytotoxicity. Finally, we demonstrated the therapeutic effect of targeting CCR8 in a murine model of lung cancer. These findings reveal the significance of CCR8+ Tregs for immunosuppression in lung cancer, especially via cytotoxic T lymphocyte cell suppression, and suggest the potential value of CCR8-targeted therapy for cancer treatment.

HMGB1-mediated autophagy promotes gefitinib resistance in human non-small cell lung cancer

Non-small cell lung cancer (NSCLC) ranks the first in incidence and mortality among malignant tumors in China. Molecular targeted therapies such as gefitinib, an oral inhibitor of the epidermal growth factor receptor tyrosine kinase, have shown significant benefits in patients with advanced NSCLC. However, most patients have unsatisfactory outcomes due to the development of drug resistance, and there is an urgent need to better understand the pathways involved in the resistance mechanisms. In this study, we found that HMGB1 is highly expressed in drug-resistant cells and confers to gefitinib resistance in NSCLC cells via activating autophagy process. Gefitinib upregulates HMGB1 expression in time-dependent and dose-dependent manners in human NSCLC cells. RNA interference-mediated knockdown of HMGB1 reduces PC9GR cell viability, induces apoptosis, and partially restores gefitinib sensitivity. Mechanistic analyses indicate that elevated HMGB1 expression contributes to gefitinib resistance by inducing autophagy. Thus, our results suggest that HMGB1 is an autophagy regulator and plays a key role in gefitinib resistance of NSCLC.

Aloe emodin 3-O-glucoside inhibits cell growth and migration and induces apoptosis of non-small-cell lung cancer cells via suppressing MEK/ERK and Akt signalling pathways

AIMS

Non-small-cell lung cancer (NSCLC) is the most frequent type of lung cancer with a high mortality rate. Glycosylation of phenolic compounds may increase water-solubility and pharmacological activities and reduce the toxicity of aglycones. This study aimed to evaluate and compare the anticancer effect of aloe emodin 3-O-glucoside (AE3G) and its aglycone, aloe emodin (AE), against NSCLC.

MAIN METHOD

A human adenocarcinoma cell line (A549) and BALB/c nu/nu xenograft mice harboring A549 cells were used as the NSCLC models. Inhibition of cell migration, disruption of mitochondrial membrane potential (MMP), DNA fragmentation, and expression levels of apoptotic proteins were measured by western blot, wound healing assay, JC-1 staining, or TUNEL staining. Histopathological changes in tumour tissues were observed by H&E and TUNEL staining.

RESULTS

With no significant cytotoxicity against noncancerous cells (Vero cells), AE3G (5-50 μM) significantly and more effectively inhibited the growth, attachment, migration, Bcl-2 expression, and activation of MEK/ERK and Akt signalling proteins and induced cytochrome c release and Bax expression in A549 cells than AE. AE3G augmented the collapse of MMP, cleavage of caspases (caspase 9, 8, and 3) and PARP, and DNA fragmentation. Intraperitoneal injection of AE3G (13 and 26 mg/kg/day) reduced the tumour volume and weight and induced apoptotic cell death in tumour tissues of xenograft NSCLC mice.

SIGNIFICANCE

The present study demonstrated that AE3G significantly and more effectively diminished human NSCLC cell growth and migration by triggering mitochondria-dependent intrinsic apoptosis than AE, providing AE3G as a new potent candidate to prevent or treat human NSCLC.

Cost-effectiveness of stereotactic body radiotherapy in the treatment of non-small-cell lung cancer (NSCLC): a systematic review

OBJECTIVES

This study aims to systematically review the studies on the cost-effectiveness of stereotactic body radiotherapy (SBRT) in the treatment of non-small-cell lung cancer (NSCLC).

METHODS

A systematic literature search was performed in databases from 2000 through April 2021. The search terms included 'economics,' 'cost,' 'cost effectiveness,' 'SBRT,' and all names for NSCLC. Two reviewers independently screened the titles, abstracts and full texts to determine the studies for the final sample. The quality of the included studies was assessed using the Quality of Health Economic Studies checklist.

RESULTS

Eleven studies were identified and included in our final review. SBRT was reported to be a cost-effective (5 of 5) option compared to conventional radiotherapy, radiofrequency ablation, and best supportive care for medically inoperable, early-stage NSCLC. However, the identified studies revealed that no single treatment was found to be more cost-effective than others between SBRT and surgical interventions. The key drivers of this cost-effectiveness were the cost of the treatment, utility value, and the rate of surgical mortality.

CONCLUSIONS

SBRT may be considered a more cost-effective strategy for medically inoperable, early-stage NSCLC. Considering the limited studies available, more related research should be conducted to further validate these results.

Small cell lung cancer transformation: From pathogenesis to treatment

Small cell lung cancer (SCLC) is a type of neuroendocrine tumor with high malignancy and poor prognosis. Besides the de novo SCLC, there is transformed SCLC, which has similar characteristics of pathological morphology, molecular characteristics, clinical manifestations and drug sensitivity. However, de novo SCLC and transformed SCLC have different pathogenesis and tumor microenvironment. SCLC transformation is one of the mechanisms of resistance to chemotherapy, immunotherapy, and targeted therapy in NSCLC. Two hypotheses have been used to explain the pathogenesis of SCLC transformation. Although SCLC transformation is not common in clinical practice, it has been repeatedly identified in many small patient series and case reports. It usually occurs in epidermal growth factor receptor (EGFR) mutant lung adenocarcinoma after treatment with tyrosine kinase inhibitors (TKIs). SCLC transformation can also occur in anaplastic lymphoma kinase (ALK)-positive lung cancer after treatment with ALK inhibitors and in wild-type EGFR or ALK NSCLC treated with immunotherapy. Chemotherapy was previously used to treat transformed SCLC, yet it is associated with an unsatisfactory prognosis. We comprehensively review the advancements in transformed SCLC, including clinical and pathological characteristics, and the potential effective treatment after SCLC transformation, aiming to give a better understanding of transformed SCLC and provide support for clinical uses.

Circular RNA hsa_circ_0077837 is upregulated in non-small cell lung cancer to downregulate phosphatase and tensin homolog through methylation

Circular RNA (circRNA) hsa_circ_0077837 inhibits colorectal cancer. Our research studied the participation of hsa_circ_0077837 in non-small cell lung cancer (NSCLC). Hsa_circ_0077837 and phosphatase and tensin homolog (PTEN) expression in cancer and paired non-cancer tissues from a total of 64 NSCLC patients were studied with RT-qPCR. To evaluate the prognostic value of hsa_circ_0077837 for NSCLC, these 64 patients were monitored for 5 years. Expression of PTEN in NSCLC cells with hsa_circ_0077837 overexpression was determined by RT-qPCR and Western blot. The methylation of PTEN gene in cells transfected with hsa_circ_0077837 expression vector was analyzed by methylation specific PCR (MSP). The roles of hsa_circ_0077837 and PTEN in NSCLC cell proliferation were evaluated using cell apoptosis assay. Our data showed that hsa_circ_0077837 was upregulated in NSCLC and predicted poor survival. Besides, hsa_circ_0077837 expression level was higher in 36 advanced cases (stage III and IV) than in 28 early-stage cases (stage I and II). Hsa_circ_0077837 was inversely correlated with PTEN across cancer tissues. In NSCLC cells, hsa_circ_0077837 overexpression decreased PTEN expression, increased PTEN gene methylation, and reduced HCC827 cell apoptosis via PTEN. Overall, hsa_circ_0077837 is upregulated in NSCLC and downregulates PTEN by increasing its gene methylation to suppress cell apoptosis.

List of abbreviations:

Non-small cell lung cancer (NSCLC); circRNAs (circular RNAs); methylation-specific PCR (MSP)