Targeted Therapy and Immune Therapy for Small Cell Lung Cancer

The occurrence of asthma in an extensive-stage small-cell lung cancer patient after combination therapy with atezolizumab and anlotinib: a case report

Background

Extensive-stage small-cell lung cancer (ES-SCLC) is highly malignant, with early metastasis and high recurrence. Since therapeutic options are limited, ES-SCLC has a characteristically short survival period and extremely poor prognosis. A combination of immune checkpoint inhibitors (ICIs) and anti-angiogenic drugs can achieve promising efficacy and safety in patients with ES-SCLC as a second-line or subsequent treatment, extending survival to some extent. However, the clinical outcomes remain mostly unsatisfactory and are sometimes affected by treatment-related adverse events.

Case presentation

A 57-year-old woman with ES-SCLC was administered a combination therapy of atezolizumab (a PD-L1 inhibitor) and anlotinib [an oral multi-targeted tyrosine kinase inhibitor (TKI)]. She survived for 22 months, with no disease progression during the 28 courses of therapy. Unexpectedly, despite having no history of asthma, the patient developed asthma while receiving this regimen. This is possibly related to T-cell activation and the tumor immune microenvironment, which induce allergic inflammation after PD-L1 blockade.

Conclusions

This is the first report of an asthma-negative ES-SCLC patient who developed asthma after receiving atezolizumab plus anlotinib. Although this combination therapy may effectively extend survival in SCLC patients, asthmatic symptoms should be closely monitored.

Prognostic value of miR-219-5p in relation to mortality in patients with small cell lung cancer: a retrospective, observational cohort study in China

OBJECTIVES

Small cell lung cancer (SCLC) is a lethal human malignancy, and previous studies support the contribution of microRNA to cancer progression. The prognostic value of miR-219-5p in patients with SCLC remains unclear. This study aimed to evaluate the predictive value of miR-219-5p with respect to mortality in patients with SCLC and to incorporate miR-219-5p level into a prediction model and nomogram for mortality.

DESIGN

Retrospective observational cohort study.

SETTING AND PARTICIPANTS

Our main cohort included data from 133 patients with SCLC between 1 March 2010 and 1 June 2015 from the Suzhou Xiangcheng People's Hospital. Data from 86 patients with non-SCLC at Sichuan Cancer Hospital and the First Affiliated Hospital of Soochow University were used for external validation.

OUTCOME MEASURES

Tissue samples were taken during admission and stored, and miR-219-5p levels were measured at a later date. A Cox proportional hazard model was used for survival analyses and for analysing risk factors to create a nomogram for mortality prediction. The accuracy of the model was evaluated by C-index and calibration curve.

RESULTS

Mortality in patients with a high level of miR-219-5p (≥1.50) (n=67) was 74.6%, while mortality in the low-level group (n=66) was 100.0%. Based on univariate analysis, we included significant factors (p<0.05) in a multivariate regression model: patients with high level of miR-219-5p (HR 0.39, 95% CI 0.26-0.59, p<0.001), immunotherapy (HR 0.44, 95% CI 0.23-0.84, p<0.001) and prognostic nutritional index score >47.9 (HR=0.45, 95% CI 0.24-0.83, p=0.01) remained statistically significant factors for improved overall survival. The nomogram had good accuracy in estimating the risk, with a bootstrap-corrected C-index of 0.691. External validation indicated an area under the curve of 0.749 (0.709-0.788).

CONCLUSIONS

The miR-219-5p level was associated with a reduced risk of mortality in patients with SCLC. A nomogram incorporating MiR-219-5p level and clinical factors demonstrated good accuracy in estimating the risk of overall mortality. Prospective validation of the prognostic nomogram is needed.

Efficacy and safety of anlotinib combined with PD-1/PD-L1 inhibitors as second-line and subsequent therapy in advanced small-cell lung cancer

OBJECTIVES

Treatments for advanced small-cell lung cancer (SCLC) patients who are resistant to first-line chemotherapy are limited. Given that antiangiogenic agents and immune-checkpoint inhibitors (ICIs) can confer synergistic therapeutic benefits, combination therapy should be considered. We explored the efficacy and safety of combination therapy with anlotinib and programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitors as second-line and subsequent therapy for advanced SCLC.

MATERIALS AND METHODS

We reviewed advanced SCLC patients at Shanghai Chest Hospital who had received anlotinib in combination with ICIs from November 2016 to November 2020 as second- and subsequent-line treatment. Patients with advanced SCLC who had received paclitaxel monotherapy as second-line treatment were included as the control group.

RESULTS

A total of 141 patients were included in the final analysis (40 in the combination therapy group and 101 in the paclitaxel monotherapy group). The median progression-free survival (PFS) times for the combination therapy and paclitaxel monotherapy groups were 3.40 and 2.83 months (p = 0.022), respectively, while the median overall survival (OS) times for the combination therapy and paclitaxel monotherapy groups were 8.20 and 5.87 months (p = 0.048), respectively. Hypertension and hepatic dysfunction were the most pronounced adverse events of combination therapy and two patients changed regimens due to severe fatigue and anorexia.

CONCLUSION

The combination of anlotinib and PD-1/PD-L1 blockade has promising efficacy and safety as a second-line or subsequent therapy for SCLC.

Challenges in the treatment of small cell lung cancer in the era of immunotherapy and molecular classification

For many years the standard of care for small cell lung cancer (SCLC) has remained unchanged. Despite decades of active research, current treatment options are limited and the prognosis of patients with extended disease (ED) SCLC remains poor. The introduction of immune checkpoint inhibitors (ICIs) represents an exception and the only recent approval for ED-SCLC. However, the magnitude of benefit obtained with immunotherapy in SCLC is much more modest than that observed in other malignancies. Different pro-immunogenic or immunosuppressive features within the tumor microenvironment of SCLC may either modulate the sensitivity to immunotherapy or conversely dampen the efficacy of ICIs. Beside immunotherapy, a deeper understanding of the molecular biology of SCLC has led to the identification of new therapeutic targets for this lethal malignancy. Recent epigenetic and gene expression studies have resulted into a new molecular classification of four distinct subtypes of SCLC, defined by the relative expression of key transcription regulators and each characterized by specific therapeutic vulnerabilities. This review discusses the rationale for immunotherapy in SCLC and summarizes the main ICIs-trials in this tumor. We provide also an overview of new potential therapeutic opportunities and their integration with the new molecular classification of SCLC.

Myricetin activates the Caspase-3/GSDME pathway via ER stress induction of pyroptosis in lung cancer cells

Pyroptosis is related to the occurrence, development, and therapeutic response of tumors, mediated by the proteins of the Gasdermin family. These proteins have become potential biomarkers for cancer treatment, and their agonists are likely to become a new direction in research and development of antitumor drugs. In this study, we found that myricetin has an inhibitory effect on lung cancer cells of the activation of pyroptosis. Analysis of the expression of Gasdermin family proteins revealed that this phenomenon was caused by the cleavage of GSDME. Subsequently, specific inhibitors, we found that caspase-3 was its upstream activation factor. In addition, mitochondrial and endoplasmic reticulum (ER) analysis showed that myricetin can cause endoplasmic reticulum stress and increase reactive oxygen species (ROS) levels. Subsequent inhibition of caspase-12 revealed that the expression levels of cleaved-caspase-3 and cleaved-GSDME were significantly reduced, resulting in the inhibition of pyroptosis. Using in vivo experiments, we also found that the treatment with myricetin can reduce tumor volume and significantly increase the level of pyroptosis-related proteins in tumor tissues. Overall, our findings show that myricetin induces cell death of lung cancer cells primarily through an ER stress pathway-induced pyroptosis. Therefore, myricetin has the potential to be used as a pyroptosis agonist in research and development of antitumor drugs.

Identification of a prognostic immune-related signature for small cell lung cancer

Purpose

As a subgroup of lung cancer, small cell lung cancer (SCLC) is characterized by a short tumor doubling time, high rates of early occurred distant cancer spread, and poor outcomes. Despite its exquisite sensitivity to chemotherapy and radiotherapy, acquired drug resistance and tumor progression are typical. This study aimed to develop a robust signature based on immune‐related genes to predict the outcome of patients with SCLC.

Methods

The expression data of 77 SCLC patients from George's cohort were divided into training set and testing set, and 1534 immune‐related genes from ImmPort database were used to generate and validate the signature. Cox proportional hazards and the Kaplan–Meier analysis were used for developing and testing the prognostic signature. Single‐sample gene set enrichment analysis was used to determine immune cell infiltration phenotypes.

Results

A 10‐gene model comprising NR3C1, NR1D2, TANK, ARAF, HDGF, INHBE, LRSAM1, PLXNA1, PML, and SP1 with the highest frequency after 1000 interactions, was chosen to construct immune‐related signature. This signature showed robust predictive value for SCLC patients’ survival in both training and testing sets. This signature was weakly associated with the clinic pathological values like TNM stage. Furthermore, patients with low risk presented with activation of immune signal pathways, and specific immune cell infiltration with high levels of CD56^bright NK cells but low levels of CD8⁺ T cells, mast cells, and helper T cells.

Conclusion

The present study developed immune‐related signature that may help predict the prognosis of SCLC patients, which reflects an unappreciated level of heterogeneity of immunophenotype associated with diverse prognosis for specific subsets in this highly lethal cancer type.

Advances in Treatment of Recurrent Small Cell Lung Cancer (SCLC): Insights for Optimizing Patient Outcomes from an Expert Roundtable Discussion

Second-line treatment options for patients with relapsed, extensive-stage small cell lung cancer (ES-SCLC) are limited, and even with currently available treatments, prognosis remains poor. Until recently, topotecan (a topoisomerase I inhibitor) was the only drug approved by the United States (US) Food and Drug Administration (FDA) for the management of ES-SCLC following progression after first-line treatment with etoposide plus a platinum derivative (EP; carboplatin preferred). With the most recent approval of EP plus a programmed death ligand 1 (PD-L1) inhibitor, there are now more therapeutic options for managing ES-SCLC. A number of novel agents have emerging data for activity in relapsed ES-SCLC, and single-agent lurbinectedin (an alkylating drug and selective inhibitor of oncogenic transcription and DNA repair machinery in tumor cells) has conditional FDA approval for use in this patient population. Trilaciclib, a short-acting cyclin-dependent kinase 4/6 (CDK 4/6) inhibitor, has also been recently approved as a supportive intervention for use prior to an EP or a topotecan-containing regimen to diminish the incidence of chemotherapy-induced myelosuppression. The current review is based on a recent expert roundtable discussion and summarizes current therapeutic agents and emerging data on newer agents and biomarkers. It also provides evidence-based clinical considerations and a treatment decision tool for oncologists treating patients with relapsed ES-SCLC. This paper discusses the importance of various factors to consider when selecting a second-line treatment option, including prior first-line treatment, available second-line treatment options, tumor platinum sensitivity, and patient characteristics (such as performance status, comorbidities, and patient-expressed and perceived values).

Absence of Biomarker-Driven Treatment Options in Small Cell Lung Cancer, and Selected Preclinical Candidates for Next Generation Combination Therapies

Lung cancer is the second most common cancer in the United States, and small cell lung cancer (SCLC) accounts for about 15% of all lung cancers. In SCLC, more than other malignancies, the standard of care is based on clinical demonstration of efficacy, and less on a mechanistic understanding of why certain treatments work better than others. This is in large part due to the virulence of the disease, and lack of clinically or biologically relevant biomarkers beyond routine histopathology. While first line therapies work in the majority of patients with extensive stage disease, development of resistance is nearly universal. Although neuroendocrine features, Rb and p53 mutations are common, the current lack of actionable biomarkers has made it difficult to develop more effective treatments. Some progress has been made with the application of immune checkpoint inhibitors. There are new agents, such as lurbinectedin, that have completed late-phase clinical testing while other agents are still in the pre-clinical phase. ONC201/TIC10 is an imipridone with strong in vivo and in vitro antitumor properties and activity against neuroendocrine tumors in phase 1 clinical testing. ONC201 activates the cellular integrated stress response and induces the TRAIL pro-apoptotic pathway. Combination treatment of lurbinectedin with ONC201 are currently being investigated in preclinical studies that may facilitate translation into clinical trials for SCLC patients.

Efficacy and Safety of Niraparib as Maintenance Treatment in Patients With Extensive-Stage SCLC After First-Line Chemotherapy: A Randomized, Double-Blind, Phase 3 Study

INTRODUCTION

ZL-2306-005 is a randomized, double-blind, multicenter phase 3 study evaluating the efficacy and safety of niraparib, a poly(adenosine diphosphate-ribose) polymerase inhibitor, as first-line maintenance therapy in Chinese patients with platinum-responsive, extensive-stage SCLC (ES-SCLC).

METHODS

Patients with complete response (CR) or partial response (PR) to standardized, platinum-based first-line chemotherapy were randomized 2:1 to receive niraparib or placebo (300 mg [baseline body weight ≥ 77 kg, platelet count ≥ 150,000/μL] or 200 mg) once daily until progression or unacceptable toxicity. Primary end points were progression-free survival (PFS) (blinded independent central review) and overall survival (sample size planned: 591 patients). Secondary end points included investigator-evaluated PFS and safety.

RESULTS

ZL-2306-005 was terminated early owing to ES-SCLC treatment landscape changes (data cutoff: March 20, 2020). During July 2018-February 2020, a total of 185 of 272 patients screened were randomized (niraparib: n = 125 [CR = 1, PR = 124]; placebo: n = 60 [CR = 1, PR = 59]). Median (95% confidence interval [CI]) PFS (blinded independent central review) was 1.54 months (1.41-2.69, niraparib) and 1.36 months (1.31-1.48, placebo); hazard ratio (HR) = 0.66 (95% CI: 0.46-0.95, p = 0.0242). Median overall survival was 9.92 months (9.33-13.54, niraparib) and 11.43 months (9.53-not estimable, placebo); HR = 1.03 (95% CI: 0.62-1.73, p = 0.9052). Median investigator-evaluated PFS was 1.48 months (1.41-2.56, niraparib) and 1.41 months (1.31-2.00, placebo); HR = 0.88 (95% CI: 0.61-1.26; p = 0.4653). Grade greater than or equal to 3 adverse events occurred in 34.4% (niraparib) and 25.0% (placebo) of patients.

CONCLUSIONS

ZL-2306-005 did not reach primary end points. Nevertheless, niraparib as maintenance therapy modestly improved PFS in patients with platinum-responsive ES-SCLC, with acceptable tolerability profile and no new safety signal.

Polo-Like Kinase 4's Critical Role in Cancer Development and Strategies for Plk4-Targeted Therapy

Polo-like kinases (Plks) are critical regulatory molecules during the cell cycle process. This family has five members: Plk1, 2, 3, 4, and 5. Plk4 has been identified as a master regulator of centriole replication, and its aberrant expression is closely associated with cancer development. In this review, we depict the DNA, mRNA, and protein structure of Plk4, and the regulation of Plk4 at a molecular level. Then we list the downstream targets of Plk4 and the hallmarks of cancer associated with these targets. The role of Plk4 in different cancers is also summarized. Finally, we review the inhibitors that target Plk4 in the hope of discovering effective anticancer drugs. From authors' perspective, Plk4 might represent a valuable tumor biomarker and critical target for cancer diagnosis and therapy.

Combination therapy: Future directions of immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC), an aggressive and devastating malignancy, is characterized by rapid growth and early metastasis. Although most patients respond to first-line chemotherapy, the majority of patients rapidly relapse and have a relatively poor prognosis. Fortunately, immunotherapy, mainly including antibodies that target the cytotoxic T lymphocyte antigen-4 (CTLA-4), checkpoints programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) to block immune regulatory checkpoints on tumor cells, immune cells, fibroblasts cells and endothelial cells, has achieved the milestone in several solid tumors, such as melanoma and non-small-cell lung carcinomas (NSCLC). In recent years, immunotherapy has made progress in the treatment of patients with SCLC, while its response rate is relatively low to monotherapy. Interestingly, the combination of immunotherapy with other therapy, such as chemotherapy, radiotherapy, and targeted therapy, preliminarily achieve greater therapeutic effects for treating SCLC. Combining different immunotherapy drugs may act synergistically because of the complementary effects of the two immune checkpoint pathways (CTLA-4 and PD-1/PD-L1 pathways). The incorporation of chemoradiotherapy in immunotherapy may augment antitumor immune responses because chemoradiotherapy can enhance tumor cell immunogenicity by rapidly inducing tumor lysis and releasing tumor antigens. In addition, since immunotherapy drugs and the molecular targets drugs act on different targets and cells, the combination of these drugs may achieve greater therapeutic effects in the treatment of SCLC. In this review, we focused on the completed and ongoing trials of the combination therapy for immunotherapy of SCLC to find out the rational combination strategies which may improve the outcomes for SCLC.

Squamous cell carcinoma mimics small cell carcinoma of the lung: a case report

Squamous cell carcinomas (SCC) accounts for roughly 20% of lung cancers in the USA. The 2015 World Health Organization classification of lung tumors further categorizes SCC as three subtypes: keratinizing, non-keratinizing and basaloid variant. The non-keratinizing subtype is a poorly differentiated tumor that can present histologically in different ways, and one of which is a rare variant that strongly resembles small cell carcinoma. As a result, histological diagnosis alone is not sufficient to properly diagnose lung carcinomas. Immunohistochemistry has been increasingly used over the past few years to differentiate between lung tumors. The combination of morphological and immunohistochemical staining should be the mainstay for diagnosis of all lung carcinomas as more targeted therapies become more available.

Artificial Intelligence Tools for Refining Lung Cancer Screening

Nearly one-quarter of all cancer deaths worldwide are due to lung cancer, making this disease the leading cause of cancer death among both men and women. The most important determinant of survival in lung cancer is the disease stage at diagnosis, thus developing an effective screening method for early diagnosis has been a long-term goal in lung cancer care. In the last decade, and based on the results of large clinical trials, lung cancer screening programs using low-dose computer tomography (LDCT) in high-risk individuals have been implemented in some clinical settings, however, this method has various limitations, especially a high false-positive rate which eventually results in a number of unnecessary diagnostic and therapeutic interventions among the screened subjects. By using complex algorithms and software, artificial intelligence (AI) is capable to emulate human cognition in the analysis, interpretation, and comprehension of complicated data and currently, it is being successfully applied in various healthcare settings. Taking advantage of the ability of AI to quantify information from images, and its superior capability in recognizing complex patterns in images compared to humans, AI has the potential to aid clinicians in the interpretation of LDCT images obtained in the setting of lung cancer screening. In the last decade, several AI models aimed to improve lung cancer detection have been reported. Some algorithms performed equal or even outperformed experienced radiologists in distinguishing benign from malign lung nodules and some of those models improved diagnostic accuracy and decreased the false-positive rate. Here, we discuss recent publications in which AI algorithms are utilized to assess chest computer tomography (CT) scans imaging obtaining in the setting of lung cancer screening.

A novel target anti-interleukin-13 receptor subunit alpha-2 monoclonal antibody inhibits tumor growth and metastasis in lung cancer

IL13Rα2 shows high expression in different types of tumors and can be a target for cancer therapy in humans due to its poor prognosis. The aim of our study is to characterize and investigate the effect of interleukin-13 receptor subunit alpha-2monoclonal antibody mAb15D8 on lung cancer cells in vitro and in vivo by blocking its specific epitope in IL13Rα2 antigen. The mAb15D8 blocking epitope was analyzed through the mutagenesis of IL13Rα2 and confirmed with western blot. We found that the IL13Rα2 epitope recognized by mAb15D8 antibody is a new binding site localized in the fibronectin-III domain-1 of IL13Rα2 antigen. Moreover, the mAb15D8 obviously reduced cell proliferation, migration of H460, A549, SKOV3, and B16F10 cells. Treatment with mAb15D8 significantly reduced the H460 xenograft tumor formation and growth in nude mice and inhibited B16F10 tumor metastasis and increased survival in C57BL/6 mice. Pharmacokinetic and toxicological analysis demonstrated the safety of mAb15D8 as a potential therapeutic agent. We developed a novel mouse monoclonal antibody against IL13Rα2 which binds to specific epitope on IL13Rα2 antigen. In vivo treatment with the antibody significantly reduced tumor growth and lung metastasis and prolonged survival. These results suggest mAb15D8 antibody as a potential therapeutic agent for cancer therapy.

Exosomal miR-141 promotes tumor angiogenesis via KLF12 in small cell lung cancer

BACKGROUND

Angiogenesis, a basic requirement for tumor cell survival, is considered to be a malignant characteristic of small cell lung cancer (SCLC) and is closely related to the poor outcomes of SCLC patients. miR-141 has been found to play pro- and antiangiogenic roles in different cancers, but its role in SCLC angiogenesis has never been explored.

METHODS

Total RNA was isolated from plasm exosomes and serum of SCLC patients to examine the expression of miR-141 by qRT-PCR. Cell proliferation, invasion, migration, tube formation assay, aortic ring assay and mouse tumor model were used to investigate the effect of exosomal miR-141 in angiogenesis in vitro and in vivo. Dual-luciferase assay was conducted to explore the target gene of miR-141.

RESULTS

Circulating miR-141 was upregulated in samples from 122 SCLC patients compared with those from normal volunteers and that the increase in miR-141 was significantly associated with advanced TNM stages, implying the potential oncogenic role of miR-141 in SCLC malignancy. In vitro, miR-141 that was packaged into SCLC cell-secreted exosomes and delivered to human umbilical vein vascular endothelial cells (HUVECs) via exosomes facilitated HUVEC proliferation, invasion, migration and tube formation and promoted microvessel sprouting from mouse aortic rings. Matrigel plug assays demonstrated that SCLC cell-derived exosomal miR-141 induced neoangiogenesis in vivo. Furthermore, mouse subcutaneous tumor nodules that were developed from miR-141-overexpressing SCLC cells had a higher microvessel density (MVD) and grew faster than those developed from negative control cells. KLF12 was found to be the direct target gene of miR-141 and that the proangiogenic effect of miR-141 on HUVECs was abrogated by KLF12 overexpression.

CONCLUSIONS

Our results demonstrate the specific function of the exosomal miR-141/KLF12 pathway in SCLC angiogenesis for the first time and provide potential novel targets for antiangiogenic therapies for SCLC patients.

Opportunities and obstacles of targeted therapy and immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive malignant tumour which accounts for approximately 13-15% of all newly diagnosed lung cancer cases. To date, platinum-based chemotherapy are still the first-line treatments for SCLC. However, chemotherapy resistance and systemic toxicity limit the long-term clinical outcome of first-line treatment in SCLC. Recent years, targeted therapy and immunotherapy have made great breakthrough in cancer therapy, and researchers aim to exploit both as a single agent or in combination with chemotherapy to improve the survival of SCLC patients, but limited effectiveness and the adverse events remain the major obstacles in the treatment of SCLC. To overcome these challenges for SCLC therapies, prevention and early diagnosis for this refractory disease is very important. At the same time, we should reveal more information about the pathogenesis of SCLC and the mechanism of drug resistance. Finally, new treatment strategies should also be taken into considerations, such as repurposing drug, optimising of targets, combination therapy strategies or prognostic biomarkers to enhance therapeutic effects and decrease the adverse events rates in SCLC patients. This article will review the molecular biology characteristics of SCLC and discuss the opportunities and obstacles of the current therapy for SCLC patients.

The contribution of hereditary cancer-related germline mutations to lung cancer susceptibility

Background

Germline variations may contribute to lung cancer susceptibility besides environmental factors. The influence of germline mutations on lung cancer susceptibility and their correlation with somatic mutations has not been systematically investigated.

Methods

In this study, germline mutations from 1,026 non-small cell lung cancer (NSCLC) patients were analyzed with a 58-gene next-generation sequencing (NGS) panel containing known hereditary cancer-related genes, and were categorized based on American College of Medical Genetics and Genomics (ACMG) guidelines in pathogenicity, and the corresponding somatic mutations were analyzed using a 605-gene NGS panel containing known cancer-related genes.

Results

Plausible genetic susceptibility was found in 4.7% of lung cancer patients, in which 14 patients with pathogenic mutations (P group) and 34 patients with likely-pathogenic mutations (LP group) were identified. The ratio of the first degree relatives with lung cancer history of the P groups was significantly higher than the Non-P group (P=0.009). The ratio of lung cancer patients with history of other cancers was higher in P (P=0.0007) or LP (P=0.017) group than the Non-P group. Pathogenic mutations fell most commonly in BRCA2, followed by CHEK2 and ATM. Likely-pathogenic mutations fell most commonly in NTRK1 and EXT2, followed by BRIP1 and PALB2. These genes are involved in DNA repair, cell cycle regulation and tumor suppression. By comparing the germline mutation frequency from this study with that from the whole population or East Asian population (gnomAD database), we found that the overall odds ratio (OR) for P or LP group was 17.93 and 15.86, respectively, when compared with the whole population, and was 2.88 and 3.80, respectively, when compared with the East Asian population, suggesting the germline mutations of the P and LP groups were risk factors for lung cancer. Somatic mutation analysis revealed no significant difference in tumor mutation burden (TMB) among the groups, although a trend of lower TMB in the pathogenic group was found. The SNV/INDEL mutation frequency of TP53 in the P group was significantly lower than the other two groups, and the copy number variation (CNV) mutation frequency of PIK3CA and MET was significantly higher than the Non-P group. Pathway enrichment analysis found no significant difference in aberrant pathways among the three groups.

Conclusions

A proportion of 4.7% of patients carrying germline variants may be potentially linked to increased susceptibility to lung cancer. Patients with pathogenic germline mutations exhibited stronger family history and higher lung cancer risk.

Genomic based analyses reveal unique mutational profiling and identify prognostic biomarker for overall survival in Chinese small-cell lung cancer

OBJECTIVE

As an aggressive subtype of lung cancer, small-cell lung cancer (SCLC) presents a poor prognosis. Although molecular and clinical characteristics have been established for SCLC, limited investigation has been performed for predicting survival of SCLC patients.

METHODS

Genomic alterations were profiled in Chinese SCLC patients (N = 37) using targeted sequencing. Clonal mutation burden (CMB) integrated the number of mutations with the clonal structure of the tumor. Specific pathways involving DNA damage repair (DDR) and cell cycle as well as CMB were studied as potential biomarkers for prognosis of SCLC.

RESULTS

TP53 and RB1 gene mutations were the most common alterations (91.9% and 83.8%, respectively), followed by LRP1B, FAM135B, SPTA1, KMT2D, FAT1, and NOTCH3. Survival analysis revealed that mutation status of the DDR pathway was associated with worse OS in our cohort. Importantly, patients with higher CMB exhibited worse OS in our cohort and this observation was successfully validated in the cBioportal cohort. Moreover, multivariate analysis demonstrated CMB as a promising independent prognostic factor for OS in Chinese SCLC patients. Interestingly, patients with loss of function of RB1, validated by immunohistochemistry staining, appeared to have worse OS.

CONCLUSIONS

The mutational profiling of Chinese SCLC patients signified an ethnicity dependent component. CMB was firstly found to be associated with OS of Chinese SCLC patients and could be regarded as a prognostic marker for SCLC.

Molecular Links Between Angiogenesis and Neuroendocrine Phenotypes in Prostate Cancer Progression

As a common therapy for prostate cancer, androgen deprivation therapy (ADT) is effective for the majority of patients. However, prolonged ADT promotes drug resistance and progression to an aggressive variant with reduced androgen receptor signaling, so called neuroendocrine prostate cancer (NEPC). Until present, NEPC is still poorly understood, and lethal with no effective treatments. Elevated expression of neuroendocrine related markers and increased angiogenesis are two prominent phenotypes of NEPC, and both of them are positively associated with cancers progression. However, direct molecular links between the two phenotypes in NEPC and their mechanisms remain largely unclear. Their elucidation should substantially expand our knowledge in NEPC. This knowledge, in turn, would facilitate the development of effective NEPC treatments. We recently showed that a single critical pathway regulates both ADT-enhanced angiogenesis and elevated expression of neuroendocrine markers. This pathway consists of CREB1, EZH2, and TSP1. Here, we seek new insights to identify molecules common to pathways promoting angiogenesis and neuroendocrine phenotypes in prostate cancer. To this end, our focus is to summarize the literature on proteins reported to regulate both neuroendocrine marker expression and angiogenesis as potential molecular links. These proteins, often described in separate biological contexts or diseases, include AURKA and AURKB, CHGA, CREB1, EZH2, FOXA2, GRK3, HIF1, IL-6, MYCN, ONECUT2, p53, RET, and RB1. We also present the current efforts in prostate cancer or other diseases to target some of these proteins, which warrants testing for NEPC, given the urgent unmet need in treating this aggressive variant of prostate cancer.

FGFRL1 affects chemoresistance of small-cell lung cancer by modulating the PI3K/Akt pathway via ENO1

Fibroblast growth factor receptor‐like 1 (FGFRL1), a member of the FGFR family, has been demonstrated to play important roles in various cancers. However, the role of FGFRL1 in small‐cell lung cancer (SCLC) remains unclear. Our study aimed to investigate the role of FGFRL1 in chemoresistance of SCLC and elucidate the possible molecular mechanism. We found that FGFRL1 levels are significantly up‐regulated in multidrug‐resistant SCLC cells (H69AR and H446DDP) compared with the sensitive parental cells (H69 and H446). In addition, clinical samples showed that FGFRL1 was overexpressed in SCLC tissues, and high FGFRL1 expression was associated with the clinical stage, chemotherapy response and survival time of SCLC patients. Knockdown of FGFRL1 in chemoresistant SCLC cells increased chemosensitivity by increasing cell apoptosis and cell cycle arrest, whereas overexpression of FGFRL1 in chemosensitive SCLC cells produced the opposite results. Mechanistic investigations showed that FGFRL1 interacts with ENO1, and FGFRL1 was found to regulate the expression of ENO1 and its downstream signalling pathway (the PI3K/Akt pathway) in SCLC cells. In brief, our study demonstrated that FGFRL1 modulates chemoresistance of SCLC by regulating the ENO1‐PI3K/Akt pathway. FGFRL1 may be a predictor and a potential therapeutic target for chemoresistance in SCLC.

Targeting CXCR1/2: The medicinal potential as cancer immunotherapy agents, antagonists research highlights and challenges ahead

Immune suppression in the tumor microenvironment (TME) is an intractable issue in anti-cancer immunotherapy. The chemokine receptors CXCR1 and CXCR2 recruit immune suppressive cells such as the myeloid derived suppressor cells (MDSCs) to the TME. Therefore, CXCR1/2 antagonists have aroused pharmaceutical interest in recent years. In this review, the medicinal chemistry of CXCR1/2 antagonists and their relevance in cancer immunotherapy have been summarized. The development of the drug candidates, along with their design rationale, clinical status and current challenges have also been discussed.

Tumor-Targeted Drug Conjugates as an Emerging Novel Therapeutic Approach in Small Cell Lung Cancer (SCLC)

There are few effective therapies for small cell lung cancer (SCLC), a highly aggressive disease representing 15% of total lung cancers. With median survival <2 years, SCLC is one of the most lethal cancers. At present, chemotherapies and radiation therapy are commonly used for SCLC management. Few protein-targeted therapies have shown efficacy in improving overall survival; immune checkpoint inhibitors (ICIs) are promising agents, but many SCLC tumors do not express ICI targets such as PD-L1. This article presents an alternative approach to the treatment of SCLC: the use of drug conjugates, where a targeting moiety concentrates otherwise toxic agents in the vicinity of tumors, maximizing the differential between tumor killing and the cytotoxicity of normal tissues. Several tumor-targeted drug conjugate delivery systems exist and are currently being actively tested in the setting of SCLC. These include antibody-drug conjugates (ADCs), radioimmunoconjugates (RICs), small molecule-drug conjugates (SMDCs), and polymer-drug conjugates (PDCs). We summarize the basis of action for these targeting compounds, discussing principles of construction and providing examples of effective versus ineffective compounds, as established by preclinical and clinical testing. Such agents may offer new therapeutic options for the clinical management of this challenging disease in the future.

Thymoquinone attenuates phosphorylation of AKT to inhibit kidney cancer cell proliferation

Thymoquinone (Tq) is an active compound from Nigella sativa which is used in traditional medicine. The effect of Tq on kidney cancer and the pathway of action remain unproven. Herein, we report the anticancer properties of Tq on kidney cancer cells. Tq demonstrated anti-proliferative effects in A498 cells with a GI₅₀ value of 40.07 µM and Caki-1 cells with a GI50 of 51.04 µM by the MTT assay. Tq exhibited nuclear fragmentation and inhibited trans-endothelial migration of A498 and Caki-1 cells in a dose-responsive manner. Time-dependent increase in Annexin V-positive cells and sub-G₀ /G₁ cell population was observed post-Tq treatment. The compound increased Bax protein levels and reduced Bcl-2 protein levels dose dependently in cells, thereby favoring apoptosis. Tq decreased the phosphorylation of Akt in both kidney cell types. The results suggest effective anticancer activity of Tq on kidney cancer cells which may be mediated by the Akt pathway. PRACTICAL APPLICATIONS: Results from the current investigation will through more light on the mechanistic pathway of Tq activity on the inhibition of kidney cancer cell proliferation. The output of this preclinical in vitro study may be translated into better chemotherapeutics of Tq and its analogs to treat kidney cancer. However, a detailed investigation on in vivo models is recommended.

Transbronchoscopic patient biopsy-derived xenografts as a preclinical model to explore chemorefractory-associated pathways and biomarkers for small-cell lung cancer

Insufficient tumor tissue is a major barrier for cancer biology research in small-cell lung cancer (SCLC) and has driven the development of patient-derived xenografts (PDXs) from biopsy tumor tissues. Here, we utilized transbronchoscopic biopsy specimens from SCLC tumors to establish PDXs and evaluated the genomic profile using next-generation sequencing and an RNA sequencing platform. The PDX establishment rate was 54.1% (40/74). PDXs largely recapitulated the major characteristics of their corresponding primary tumors, such as histopathology, genetic profile, and chemo-responsiveness. Compared with chemosensitive (chemo-S) PDXs, chemorefractory (chemo-R) PDXs demonstrated significant gene aberrances in the mitogen-activated protein kinase (MAPK) pathway and a higher frequency of receptor tyrosine kinase (RTK)-related genes. Phosphorylated ERK (pERK) was associated with chemo-R status. Patients with positive pERK expression demonstrated significantly inferior progression-free survival after first-line chemotherapy compared with that of patients who were negative for pERK (p < 0.001). Collectively, transbronchoscopic biopsy SCLC PDXs can serve as a model for genomic profiling and identifying biomarkers predictive of chemo-R status. Using PDXs, RTK-related gene aberrances and pERK expression were found to be associated with chemo-R SCLC.