Small cell lung cancer: treatment review

In silico and in vitro investigation of dual targeting Prima-1MET as precision therapeutic against lungs cancer

This study emphasizes the explorations of binding of Prima-1MET with two targets, p53 a tumor suppressor protein, and tyrosine kinase of epidermal growth factor receptor. In silico investigations reveal that Prima-1MET showed robust binding with both targets. Molecular docking simulations demonstrated the binding affinity of Prima-1MET with p53 and tyrosine kinase was found to be -38.601 kJ/mol and -38.976 kJ/mol. In addition, the stability of Prima-1MET was explored by molecular dynamics simulation. Prima-1MET attains stability in the binding site of the respective protein till the simulation period is over. Moreover, the free binding energy ΔGbind was calculated by the molecular mechanics Poisson Boltzmann surface area method. The ΔGbind of Prima-1MET with tyrosine kinase was found to be -58.585 ± 0.327 kJ/mol and with p53 it was -35.910 ± 0.335 kJ/mol. Next, cytotoxicity of the Prima-1MET was evaluated using multiple cancer cell lines and the IC50 value were ranging between 4.5 and 30 μM. The cell death was identified by apoptosis assay. Further, the p53 and tyrosine kinase expression was monitored using immunofluorescence techniques, it was found Prima-1MET induces the expression of p53 protein and mimics the level of tyrosine kinase oncogenic target. Also, reactive oxygen species (ROS) and membrane potential activity of Prima-1MET was evaluated by using a lung cancer cell line. A significant decrease in intracellular ROS was observed and resulted in disruption of mitochondrial transmembrane potential. This study uncovers the underlying mechanism of Prima-1MET and could be helpful to design further leads against lung cancers.Communicated by Ramaswamy H. Sarma.

Combined SCLC clinical and pathological aspects

Combined small cell lung carcinoma (C-SCLC) is rare and accounts for 1-3% of all lung cancer cases. Although its incidence has increased recently, there are limited studies on it. The records of patients admitted to our hospital between January 2015 and December 2019 and diagnosed with histologically proven combined small cell were scanned retrospectively and reviewed. 31 patients were analyzed. The average follow-up time was 10 months. The radiotherapy (RT) rate, surgery rate, and large cell malignancy rate were significantly lower in the ex group than in the living group (p=0.024, p=0.023, p=0.015). The rates of extensive disease, metastasis, and thyroid transcription factor 1 (TTF1) were significantly higher in the old group than in the living group (p=0.000, p=0.000, p=0.029, respectively). In the univariate model, sequential RT, fatigue, lactate dehydrogenase (LDH), stage, metastasis, contralateral lung metastasis, chemotherapy were observed to be significantly effective in predicting survival time (p=0.000, p=0.050, p=0.011, p=0.004, p=0.004, p=0.045, p=0.009).  In the multivariate model, independent (p=0.015, p=0.022, p=0.049) efficacy of RT, stage, and chemotherapy in predicting survival was observed. C-SCLC is a specific mixed carcinoma and reports evaluating this type are still scarce. The stage of the disease, radiotherapy and chemotherapy are extremely important in predicting survival.

Reducing Chemotherapy-Induced DNA Damage via nAChR-Mediated Redox Reprograming-A New Mechanism for SCLC Chemoresistance Boosted by Nicotine

Up to 60% of patients with small cell lung cancer (SCLC) continue to smoke, which is associated with worse clinical outcomes. Platinum-based chemotherapies, in combination with topoisomerase inhibitors, are first-line therapies for SCLC, with rapid chemoresistance as a major barrier. We provided evidence in this study that nicotine and its major metabolite, cotinine, at physiologically relevant concentrations, reduced the efficacy of platinum-based chemotherapies and facilitated chemoresistance in SCLC cells. Mechanistically, nicotine or cotinine reduced chemotherapy-induced DNA damage by modulating cellular redox processes, with nAChRs as the upstream targets. Surprisingly, cisplatin treatment alone also increased the levels of nAChRs in SCLC cells, which served as a self-defense mechanism against platinum-based therapies. These discoveries were confirmed in long-term in vitro and in vivo studies. Collectively, our results depicted a novel and clinically important mechanism of chemoresistance in SCLC treatment: nicotine exposure significantly compromises the efficacy of platinum-based chemotherapies in SCLC treatment by reducing therapy-induced DNA damage and accelerating chemoresistance acquisition. The results also emphasized the urgent need for tobacco cessation and the control of NRT use for SCLC management.

Roles of MET in human cancer

The MET proto-oncogene was first identified in osteosarcoma cells exposed to carcinogens. Although expressed in many normal cells, MET is overexpressed in many human cancers. MET is involved in the initiation and development of various human cancers and mediates proliferation, migration and invasion. Accordingly, MET has been successfully used as a biomarker for diagnosis and prognosis, survival, post-operative recurrence, risk assessment and pathologic grading, as well as a therapeutic target. In addition, recent work indicates that inhibition of MET expression and function has potential clinical benefit. This review summarizes the role, mechanism, and clinical significance of MET in the formation and development of human cancer.

Signaling Pathway Inhibitors, miRNA, and Nanocarrier-Based Pharmacotherapeutics for the Treatment of Lung Cancer: A Review

Lung cancer is one of the most commonly diagnosed cancers and is responsible for a large number of deaths worldwide. The pathogenic mechanism of lung cancer is complex and multifactorial in origin. Thus, various signaling pathways as targets for therapy are being examined, and many new drugs are in the pipeline. However, both conventional and target-based drugs have been reported to present significant adverse effects, and both types of drugs can affect the clinical outcome in addition to patient quality of life. Recently, miRNA has been identified as a promising target for lung cancer treatment. Therefore, miRNA mimics, oncomiRs, or miRNA suppressors have been developed and studied for possible anticancer effects. However, these miRNAs also suffer from the limitations of low stability, biodegradation, thermal instability, and other issues. Thus, nanocarrier-based drug delivery for the chemotherapeutic drug delivery in addition to miRNA-based systems have been developed so that existing limitations can be resolved, and enhanced therapeutic outcomes can be achieved. Thus, this review discusses lung cancer's molecular mechanism, currently approved drugs, and their adverse effects. We also discuss miRNA biosynthesis and pathogenetic role, highlight pre-clinical and clinical evidence for use of miRNA in cancer therapy, and discussed limitations of this therapy. Furthermore, nanocarrier-based drug delivery systems to deliver chemotherapeutic drugs and miRNAs are described in detail. In brief, the present review describes the mechanism and up-to-date possible therapeutic approaches for lung cancer treatment and emphasizes future prospects to bring these novel approaches from bench to bedside.

ISOTOPE: ISOform-guided prediction of epiTOPEs in cancer

Immunotherapies provide effective treatments for previously untreatable tumors and identifying tumor-specific epitopes can help elucidate the molecular determinants of therapy response. Here, we describe a pipeline, ISOTOPE (ISOform-guided prediction of epiTOPEs In Cancer), for the comprehensive identification of tumor-specific splicing-derived epitopes. Using RNA sequencing and mass spectrometry for MHC-I associated proteins, ISOTOPE identified neoepitopes from tumor-specific splicing events that are potentially presented by MHC-I complexes. Analysis of multiple samples indicates that splicing alterations may affect the production of self-epitopes and generate more candidate neoepitopes than somatic mutations. Although there was no difference in the number of splicing-derived neoepitopes between responders and non-responders to immune therapy, higher MHC-I binding affinity was associated with a positive response. Our analyses highlight the diversity of the immunogenic impacts of tumor-specific splicing alterations and the importance of studying splicing alterations to fully characterize tumors in the context of immunotherapies. ISOTOPE is available at https://github.com/comprna/ISOTOPE.

The function of LncRNAs and their role in the prediction, diagnosis, and prognosis of lung cancer

Lung cancer remains a major threat to human health. Low dose CT scan (LDCT) has become the main method of early screening for lung cancer due to the low sensitivity of chest X-ray. However, LDCT not only has a high false positive rate, but also entails risks of overdiagnosis and cumulative radiation exposure. In addition, cumulative radiation by LDCT screening and subsequent follow-up can increase the risk of lung cancer. Many studies have shown that long noncoding RNAs (lncRNAs) remain stable in blood, and profiling of blood has the advantages of being noninvasive, readily accessible and inexpensive. Serum or plasma assay of lncRNAs in blood can be used as a novel detection method to assist LDCT while improving the accuracy of early lung cancer screening. LncRNAs can participate in the regulation of various biological processes. A large number of researches have reported that lncRNAs are key regulators involved in the progression of human cancers through multiple action models. Especially, some lncRNAs can affect various hallmarks of lung cancer. In addition to their diagnostic value, lncRNAs also possess promising potential in other clinical applications toward lung cancer. LncRNAs can be used as predictive markers for chemosensitivity, radiosensitivity, and sensitivity to epidermal growth factor receptor (EGFR)-targeted therapy, and as well markers of prognosis. Different lncRNAs have been implicated to regulate chemosensitivity, radiosensitivity, and sensitivity to EGFR-targeted therapy through diverse mechanisms. Although many challenges need to be addressed in the future, lncRNAs have bright prospects as an adjunct to radiographic methods in the clinical management of lung cancer.

Effectiveness of Thermal Ablation and Stereotactic Radiotherapy Based on Stage I Lung Cancer Histology

PURPOSE

To assess whether the effectiveness of thermal ablation (TA) and stereotactic body radiotherapy (SBRT) as initial treatments for stage I lung cancer varies depending on the histological subtype.

MATERIALS AND METHODS

The 2004-2016 National Cancer Database was queried for patients with American Joint Committee on Cancer stage I lung cancer treated with TA or SBRT. Patients <18 years, those treated with surgery or chemotherapy, or those with unknown survival and follow-up were excluded. TA and SBRT patients were 1:5 propensity score matched separately for each histological subtype to adjust for confounders. Overall survival (OS) was assessed using Cox models.

RESULTS

A total of 28,425 patients were included (SBRT, n = 27,478; TA, n = 947). TA was more likely to be used in Caucasian patients, those with more comorbidities and smaller neuroendocrine tumors (NETs) of the lower lobe, and those whose treatment had taken place in the northeastern United States. After propensity score matching, a cohort with 4,085 SBRT and 817 TA patients with balanced confounders was obtained. In this cohort, OS for TA and SBRT was comparable (hazard ratio = 1.07; 95% confidence interval,0.98-1.18; P = .13), although it varied by histological subtypes: higher OS for TA was observed in patients with non-small cell NETs (vs SBRT hazard ratio = 0.48; 95% confidence interval, 0.24-0.95; P = .04). No significant OS differences between TA and SBRT were noted for adenocarcinomas, squamous cell carcinomas, small cell carcinomas, and non-neuroendocrine large cell carcinomas (each, P > .1).

CONCLUSIONS

OS following TA and SBRT for stage I lung cancer is comparable for most histological subtypes, except that OS is longer after TA in non-small cell NETs.

BET-Inhibitor I-BET762 and PARP-Inhibitor Talazoparib Synergy in Small Cell Lung Cancer Cells

Small cell lung cancer (SCLC) is an aggressive type of lung cancer with high mortality that is caused by frequent relapses and acquired resistance. Despite that several target-based approaches with potential therapeutic impact on SCLC have been identified, numerous targeted drugs have not been successful in providing improvements in cancer patients when used as single agents. A combination of targeted therapies could be a strategy to induce maximum lethal effects on cancer cells. As a starting point in the development of new drug combination strategies for the treatment of SCLC, we performed a mid-throughput screening assay by treating a panel of SCLC cell lines with BETi or AKi in combination with PARPi or EZH2i. We observed drug synergy between I-BET762 and Talazoparib, BETi and PARPi, respectively, in SCLC cells. Combinatorial efficacy was observed in MYCs-amplified and MYCs-wt SCLC cells over SCLC cells with impaired MYC signaling pathway or non-tumor cells. We indicate that drug synergy between I-BET762 and Talazoparib is associated with the attenuation HR-DSBR process and the downregulation of various players of DNA damage response by BET inhibition, such as CHEK2, PTEN, NBN, and FANCC. Our results provide a rationale for the development of new combinatorial strategies for the treatment of SCLC.

Natural Health Products (NHP's) and Natural Compounds as Therapeutic Agents for the Treatment of Cancer; Mechanisms of Anti-Cancer Activity of Natural Compounds and Overall Trends

Most cancer therapeutics, such as tubulin-targeting chemotherapy drugs, cause cytotoxic, non-selective effects. These harmful side-effects drastically reduce the cancer patient's quality of life. Recently, researchers have focused their efforts on studying natural health products (NHP's) which have demonstrated the ability to selectively target cancer cells in cellular and animal models. However, the major hurdle of clinical validation remains. NHP's warrant further clinical investigation as a therapeutic option since they exhibit low toxicity, while retaining a selective effect. Additionally, they can sensitize cancerous cells to chemotherapy, which enhances the efficacy of chemotherapeutic drugs, indicating that they can be utilized as supplemental therapy. An additional area for further research is the investigation of drug-drug interactions between NHP's and chemotherapeutics. The objectives of this review are to report the most recent results from the field of anticancer NHP research, and to highlight the most recent advancements in possible supplemental therapeutic options.

SIRT3 increases cisplatin sensitivity of small-cell lung cancer through apoptosis

Small-cell lung cancer (SCLC) is the most invasive of all lung cancer subtypes, and is characterized by its rapid response to chemotherapy resistance. Overcoming chemotherapy resistance is therefore the key to treating SCLC. P53 is mutated in most SCLCs, which has an effect of enhancing chemotherapy resistance. Regulation of p53 proteins by a variety of post-translational modifications, such as acetylation, which affects their function. Acetylation and deacetylation of p53 may be potential targets for modulating chemosensitivity. Recent studies have shown that SIRT3 acts as a deacetylase that regulates acetylation of p53. However, whether SIRT3 can regulate the post-translational modification of mutant p53 has not been studied. In the present study, we found that SIRT3 can deacetylate mutant p53, thus reducing its expression, inducing apoptosis in SCLC cells, and increasing SCLC chemosensitivity. The relationship between SIRT3 and mutant p53 could be the basis of a new SCLC treatment approach.

Analysis of the role of DAMTC in lung adenocarcinoma cells based on the DNA microarrays

The present study aimed to investigate the effect of 7, 8-diacetoxy-4-methylcoumarin (DAMTC) on lung adenocarcinoma cells (A549) and analyze the molecular mechanism underlying DAMTC-treated lung adenocarcinoma. Gene expression profile GSE29698 was downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) in 3 DAMTC-treated A549 samples were analyzed and compared with 3 DAMTC-untreated samples using the limma package. Gene Ontology (GO) and pathway enrichment analyses of DEGs were performed, followed by the functional annotation and protein-protein interaction (PPI) network construction. Finally, pathway crosstalk analysis was conducted. A total of 500 upregulated and 389 downregulated DEGs were identified. The upregulated and downregulated DEGs were enriched in different GO terms and pathways, including metabolic process, p53 signaling pathway and metabolic pathways. A total of 9 DEGs were determined to have node degrees >16 in the PPI network, including interleukin 6 (IL6), MDM2 oncogene, E3 ubiquitin protein ligase (MDM2), cell division cycle 42 (CDC42) and MYC associated factor X (MAX). Furthermore, numerous DEGs were identified to function as transcription factors and tumor suppressor genes, including histone deacetylase 3 and MAX. Additionally, apoptosis, tight junction, and endocytosis pathway were determined to cross-talk with small cell and non-small cell lung cancer. The DEGs (IL6, MDM2, CDC42 and MAX) involved in different pathways, including the p53 signaling pathway and endocytosis, may be the potential targets for DAMTC in lung adenocarcinoma. The elucidation of the underlying mechanism of the DAMTC effect may make it a potential drug.

Towards a high throughput impedimetric screening of chemosensitivity of cancer cells suspended in hydrogel and cultured in a paper substrate

In order to achieve high predictive value of cell chemosensitivity test for clinical efficacy, cancer cells were suggested to be encapsulated and cultured in hydrogel to mimic the natural microenvironment of tumors. However, handling 3D cells/hydrogel culture construct is tedious and cellular response is difficult to be quantitatively analyzed. In the current study, a novel platform for conducting 3D cell culture and analyzing cell viability has been developed towards a high throughput drug screening. Cells encapsulated in the hydrogel were cultured in the microwells of a paper substrate. The substrate was then immersed in the culture medium containing drug for 2 days. At 24 and 48h during the culture course, the paper substrate was placed on the measurement electrodes for conducting the impedance measurement in order to quantify the cell viability in the hydrogel. Cell viability of two human hepatoma cell lines (Huh7 and Hep-G2) was quantitatively investigated under the treatment of two drugs (doxorubicin and etoposide). The results represented by IC₅₀ values revealed that Huh7 cells had a higher drug resistance than Hep-G2 cells and doxorubicin had a higher efficacy than etoposide for treating hepatocellular carcinoma. The current work has demonstrated a high throughput, convenient, and quantitative platform for the investigation of chemosensitivity of cells cultured in the 3D environment.

Interactions between anticancer active platinum complexes and non-coding RNAs/microRNAs

Platinum(II) complexes such as cisplatin, carboplatin and oxaliplatin are clinically approved for the therapy of various solid tumors. Challenging pathogenic properties of cancer cells and the response of cancers towards platinum-based drugs are strongly influenced by non-coding small RNA molecules, the microRNAs (miRNAs). Both increased platinum activity and formation of tumor resistance towards platinum drugs are controlled by miRNAs. This review gives an overview of the interactions between platinum-based drugs and miRNAs, and their influence on platinum activity in various cancer types is discussed.

Emodin induces apoptosis of lung cancer cells through ER stress and the TRIB3/NF-κB pathway

Emodin is a phytochemical with potent anticancer activities against various human malignant cancer types, including lung cancer; however, the molecular mechanisms underlying the effects of emodin remain unclear. In the present study, the A549 and H1299 human non-small lung cancer cell lines were treated with emodin and the induced molecular effects were investigated. Changes in cell viability were evaluated by MTT assay, Hoechst staining was used to indicate the apoptotic cells, and western blotting was utilized to assess endoplasmic reticulum (ER) stress and signaling changes. RNA interference was also employed to further examine the role of tribbles homolog 3 (TRIB3) in the emodin-induced apoptosis of lung cancer cells. Emodin was found to reduce the viability of lung cancer cells and induce apoptosis in a concentration-dependent manner. Emodin-induced apoptosis was impaired by inhibition of ER stress using 4-phenylbutyrate (4-PBA). ER stress and TRIB3/nuclear factor-κB signaling was activated in emodin-treated lung cancer cells. Emodin-induced apoptosis was reduced by TRIB3 knockdown in A549 cells, whereas ER stress was not reduced. In vivo assays verified the significance of these results, revealing that emodin inhibited lung cancer growth and that the inhibitory effects were reduced by inhibition of ER stress with 4-PBA. In conclusion, the results suggest that TRIB3 signaling is associated with emodin-induced ER stress-mediated apoptosis in lung cancer cells.

Synthetic tambjamine analogues induce mitochondrial swelling and lysosomal dysfunction leading to autophagy blockade and necrotic cell death in lung cancer

Current pharmacological treatments for lung cancer show very poor clinical outcomes, therefore, the development of novel anticancer agents with innovative mechanisms of action is urgently needed. Cancer cells have a reversed pH gradient compared to normal cells, which favours cancer progression by promoting proliferation, metabolic adaptation and evasion of apoptosis. In this regard, the use of ionophores to modulate intracellular pH appears as a promising new therapeutic strategy. Indeed, there is a growing body of evidence supporting ionophores as novel antitumour drugs. Despite this, little is known about the implications of pH deregulation and homeostasis imbalance triggered by ionophores at the cellular level. In this work, we deeply analyse for the first time the anticancer effects of tambjamine analogues, a group of highly effective anion selective ionophores, at the cellular and molecular levels. First, their effects on cell viability were determined in several lung cancer cell lines and patient-derived cancer stem cells, demonstrating their potent cytotoxic effects. Then, we have characterized the induced lysosomal deacidification, as well as, the massive cytoplasmic vacuolization observed after treatment with these compounds, which is consistent with mitochondrial swelling. Finally, the activation of several proteins involved in stress response, autophagy and apoptosis was also detected, although they were not significantly responsible for the cell death induced. Altogether, these evidences suggest that tambjamine analogues provoke an imbalance in cellular ion homeostasis that triggers mitochondrial dysfunction and lysosomal deacidification leading to a potent cytotoxic effect through necrosis in lung cancer cell lines and cancer stem cells.

Treatment outcomes of patients with small cell lung cancer without prophylactic cranial irradiation

BACKGROUND

Prophylactic cranial irradiation (PCI) is indicated for limited disease (LD) in small cell lung cancer (SCLC) patients who achieve a complete or near-complete response; however, it is sometimes not administered because of possible adverse reactions or patient refusal. Here we assessed treatment outcomes among patients with SCLC who were not treated with PCI.

METHODS

The medical records of 60 patients (45 men, 15 women; mean age, 68 years; age range, 51-82 years) with SCLC were retrospectively reviewed. The tumors were staged by TNM classification. Two, 2, 5, 4, 32, and 15 patients had stage IA, IB, IIA, IIB, IIIA, and IIIB tumors, respectively. The patients were treated with thoracic radiotherapy (TRT) and four courses of chemotherapy.

RESULTS

Our subjects had a median survival of 25 months and 2- and 5-year survival rates of 52.6% and 25.3%, respectively. Univariate analysis revealed that the development of brain metastasis, performance status (PS), and T-stage were significant factors correlated with survival rate. Multivariate analysis identified only PS [hazard ratio (HR), 5.845, 95% confidence interval (CI), 2.333-14.63, P=0.002] and brain metastasis as independent prognostic variables (HR, 2.344, 95% CI, 1.071-5.128, P=0.033).

CONCLUSIONS

The results of our study demonstrated that the outcomes of treatment without PCI were improved, as compared with those of previously published data. Our findings may be used as reference data when PCI cannot be performed.

Current State of Metal-Based Drugs for the Efficient Therapy of Lung Cancers and Lung Metastases

Lung cancer is the second most common cancer in both men and women and thus a leading cause of cancer-related deaths worldwide. New efficient treatments especially for its advanced stages and metastases are desperately needed, particularly with regard to overcoming the resistance which thwarts the efficacy of most clinically established drugs such as the platinum complexes. Glimpses of hope are new metal-based drugs that have emerged over the past decade which displayed efficacy in patients with platinum-resistant tumors and metastases. This chapter provides an overview of the latest developments of such metal-based drugs against lung cancer.

Efficacy of 3D conformal thoracic radiotherapy for extensive-stage small-cell lung cancer: A retrospective study

The aim of the present study was to evaluate the effect of 3-dimensional conformal thoracic radiotherapy (TRT) on extensive-stage small-cell lung cancer (ES-SCLC). A total of 165 patients with ES-SCLC were enrolled in the present study, including 82 patients receiving chemotherapy combined with TRT (the ChT/TRT group) and 83 patients receiving chemotherapy alone (the ChT group). The overall survival (OS) and progression-free survival (PFS) rates were compared between the ChT/TRT and ChT groups, and the prognostic factors for OS rate were identified. It was found that the patients had a median OS time of 15 months, and 2- and 5-year OS rates of 31.5 and 2.4%, respectively. The 2- and 5-year OS rates were 35.3 and 2.4% in the ChT/TRT group, and 14.5 and 2.4% in the ChT group, respectively (P<0.05). The 1- and 2-year PFS rates were 35.4 and 6.0% in the ChT/TRT group, and 20.5 and 6.0% in the ChT group, respectively (P<0.05). The median PFS was 11 months in the 20 patients receiving TRT at 45 Gy/30 fractions twice daily, and 9 months in the 22 patients receiving TRT at 60 Gy/30 fractions daily (P=0.043). Multivariate analysis revealed that receiving ≥4 cycles of chemotherapy (P=0.001) and TRT (P=0.008) were favorable prognostic factors for OS. It was concluded that the addition of TRT improves the OS and PFS rates of patients with ES-SCLC, and TRT administration at 45 Gy/30 fractions twice daily is feasible and tolerable for the treatment of ES-SCLC. Thus, TRT and receiving ≥4 cycles of chemotherapy are independent, favorable prognostic factors for OS in patients with ES-SCLC.

Next-generation sequencing reveals frequent consistent genomic alterations in small cell undifferentiated lung cancer

Aims

Small cell lung cancer (SCLC) carries a poor prognosis, and the systemic therapies currently used as treatments are only modestly effective, as demonstrated by a low 5-year survival at only ∼5%. In this retrospective collected from March 2013 to study, we performed comprehensive genomic profiling of 98 small cell undifferentiated lung cancer (SCLC) samples to identify potential targets of therapy not currently searched for in routine clinical practice.

Methods

DNA from 98 SCLC was sequenced to high, uniform coverage (Illumina HiSeq 2500) and analysed for all classes of genomic alterations.

Results

A total of 386 alterations were identified for an average of 3.9 alterations per tumour (range 1–10). Fifty-two (53%) of cases harboured at least 1 actionable alteration with the potential to personalise therapy including base substitutions, amplifications or homozygous deletions in RICTOR (10%), KIT (7%), PIK3CA (6%), EGFR (5%), PTEN (5%), KRAS (5%), MCL1 (4%), FGFR1 (4%), BRCA2, (4%), TSC1 (3%), NF1 (3%), EPHA3 (3%) and CCND1. The most common non-actionable genomic alterations were alterations in TP53 (86% of SCLC cases), RB1 (54%) and MLL2 (17%).

Conclusions

Greater than 50% of the SCLC cases harboured at least one actionable alteration. Given the limited treatment options and poor prognosis of patients with SCLC, comprehensive genomic profiling has the potential to identify new treatment paradigms and meet an unmet clinical need for this disease.

Gambogenic acid kills lung cancer cells through aberrant autophagy

Lung cancer is one of the most common types of cancer and causes 1.38 million deaths annually, as of 2008 worldwide. Identifying natural anti-lung cancer agents has become very important. Gambogenic acid (GNA) is one of the active compounds of Gamboge, a traditional medicine that was used as a drastic purgative, emetic, or vermifuge for treating tapeworm. Recently, increasing evidence has indicated that GNA exerts promising anti-tumor effects; however, the underlying mechanism remains unclear. In the present paper, we found that GNA could induce the formation of vacuoles, which was linked with autophagy in A549 and HeLa cells. Further studies revealed that GNA triggers the initiation of autophagy based on the results of MDC staining, AO staining, accumulation of LC3 II, activation of Beclin 1 and phosphorylation of P70S6K. However, degradation of p62 was disrupted and free GFP could not be released in GNA treated cells, which indicated a block in the autophagy flux. Further studies demonstrated that GNA blocks the fusion between autophagosomes and lysosomes by inhibiting acidification in lysosomes. This dysfunctional autophagy plays a pro-death role in GNA-treated cells by activating p53, Bax and cleaved caspase-3 while decreasing Bcl-2. Beclin 1 knockdown greatly decreased GNA-induced cell death and the effects on p53, Bax, cleaved caspase-3 and Bcl-2. Similar results were obtained using a xenograft model. Our findings show, for the first time, that GNA can cause aberrant autophagy to induce cell death and may suggest the potential application of GNA as a tool or viable drug in anticancer therapies.

miR-335 inhibits small cell lung cancer bone metastases via IGF-IR and RANKL pathways

Small cell lung cancer (SCLC) is a rapidly progressing, incurable cancer that frequently spreads to bone. New insights are needed to identify therapeutic targets to prevent or retard SCLC metastatic progression. Human SCLC SBC-5 cells in mouse xenograft models home to skeletal and nonskeletal sites, whereas human SCLC SBC-3 cells only pervade nonskeletal sites. Because microRNAs (miRNA) often act as tumor regulators, we investigated their role in preclinical models of SCLC. miRNA expression profiling revealed selective and reduced expression of miRNA (miR)-335 and miR-29a in SBC-5 cells, compared with SBC-3 cells. In SBC-5 cells, miR-335 expression correlated with bone osteolytic lesions, whereas miR-29a expression did not. Overexpression of miR-335 in SBC-5 cells significantly reduced cell migration, invasion, proliferation, colony formation, and osteoclast induction in vitro. Importantly, in miR-335 overexpressing SBC-5 cell xenografts (n = 10), there were minimal osteolytic lesions in the majority of mice and none in three mice. Expression of RANK ligand (RANKL) and insulin-like growth factor-I receptor (IGF-IR), key mediators of bone metastases, were elevated in SBC-5 as compared with SBC-3 cells. Mechanistically, overexpression of miR-335 in SBC-5 cells reduced RANKL and IGF-IR expression. In conclusion, loss of miR-335 promoted SCLC metastatic skeletal lesions via deregulation of IGF-IR and RANKL pathways and was associated with metastatic osteolytic skeletal lesions.

IMPLICATIONS

These preclinical findings establish a need to pursue the role of miR-335 in human SCLC with metastatic skeletal disease.

Genome-wide identification of genes with amplification and/or fusion in small cell lung cancer

To obtain a landscape of gross genetic alterations in small cell lung cancer (SCLC), genome-wide copy number analysis and whole-transcriptome sequencing were performed in 58 and 42 SCLCs, respectively. Focal amplification of known oncogene loci, MYCL1 (1p34.2), MYCN (2p24.3), and MYC (8q24.21), was frequently and mutually exclusively detected. MYCL1 and MYC were co-amplified with other regions on either the same or the different chromosome in several cases. In addition, the 9p24.1 region was identified as being amplified in SCLCs without amplification of MYC family oncogenes. Notably, expression of the KIAA1432 gene in this region was significantly higher in KIAA1432 amplified cells than in non-amplified cells, and its mRNA expression showed strong correlations with the copy numbers. Thus, KIAA1432 is a novel gene activated by amplification in SCLCs. By whole-transcriptome sequencing, a total of 60 fusion transcripts, transcribed from 95 different genes, were identified as being expressed in SCLC cells. However, no in-frame fusion transcripts were recurrently detected in ≥2 SCLCs, and genes in the amplified regions, such as PVT1 neighboring MYC and RLF in MYCL1 amplicons, were recurrently fused with genes in the same amplicons or with those in different amplicons on either the same or different chromosome. Thus, it was indicated that amplification and fusion of several genes on chromosomes 1 and 8 occur simultaneously but not sequentially through chromothripsis in the development of SCLC, and amplification rather than fusion of genes plays an important role in its development.

Nuclear factor I/B is an oncogene in small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive cancer often diagnosed after it has metastasized. Despite the need to better understand this disease, SCLC remains poorly characterized at the molecular and genomic levels. Using a genetically engineered mouse model of SCLC driven by conditional deletion of Trp53 and Rb1 in the lung, we identified several frequent, high-magnitude focal DNA copy number alterations in SCLC. We uncovered amplification of a novel, oncogenic transcription factor, Nuclear factor I/B (Nfib), in the mouse SCLC model and in human SCLC. Functional studies indicate that NFIB regulates cell viability and proliferation during transformation.

MET phosphorylation predicts poor outcome in small cell lung carcinoma and its inhibition blocks HGF-induced effects in MET mutant cell lines

Background:

Small cell lung carcinoma (SCLC) has poor prognosis and remains orphan from targeted therapy. MET is activated in several tumour types and may be a promising therapeutic target.

Methods:

To evaluate the role of MET in SCLC, MET gene status and protein expression were evaluated in a panel of SCLC cell lines. The MET inhibitor PHA-665752 was used to study effects of pathway inhibition in basal and hepatocyte growth factor (HGF)-stimulated conditions. Immunohistochemistry for MET and p-MET was performed in human SCLC samples and association with outcome was assessed.

Results:

In MET mutant SCLC cells, HGF induced MET phosphorylation, increased proliferation, invasiveness and clonogenic growth. PHA-665752 blocked MET phosphorylation and counteracted HGF-induced effects. In clinical samples, total MET and p-MET overexpression were detected in 54% and 43% SCLC tumours (n=77), respectively. MET phosphorylation was associated with poor median overall survival (132 days) vs p-MET negative cases (287 days)(P<0.001). Phospho-MET retained its prognostic value in a multivariate analysis.

Conclusions:

MET activation resulted in a more aggressive phenotype in MET mutant SCLC cells and its inhibition by PHA-665752 reversed this phenotype. In patients with SCLC, MET activation was associated with worse prognosis, suggesting a role in the adverse clinical behaviour in this disease.

Hypoxic human cancer cells are sensitized to BH-3 mimetic–induced apoptosis via downregulation of the Bcl-2 protein Mcl-1

Solid tumors contain hypoxic regions in which cancer cells are often resistant to chemotherapy-induced apoptotic cell death. Therapeutic strategies that specifically target hypoxic cells and promote apoptosis are particularly appealing, as few normal tissues experience hypoxia. We have found that the compound ABT-737, a Bcl-2 homology domain 3 (BH-3) mimetic, promotes apoptotic cell death in human colorectal carcinoma and small cell lung cancer cell lines exposed to hypoxia. This hypoxic induction of apoptosis was mediated through downregulation of myeloid cell leukemia sequence 1 (Mcl-1), a Bcl-2 family protein that serves as a biomarker for ABT-737 resistance. Downregulation of Mcl-1 in hypoxia was independent of hypoxia-inducible factor 1 (HIF-1) activity and was consistent with decreased global protein translation. In addition, ABT-737 induced apoptosis deep within tumor spheroids, consistent with an optimal hypoxic oxygen tension being necessary to promote ABT-737–induced cell death. Tumor xenografts in ABT-737–treated mice also displayed significantly more apoptotic cells within hypoxic regions relative to normoxic regions. Synergies between ABT-737 and other cytotoxic drugs were maintained in hypoxia, suggesting that this drug may be useful in combination with chemotherapeutic agents. Taken together, these findings suggest that Mcl-1–sparing BH-3 mimetics may induce apoptosis in hypoxic tumor cells that are resistant to other chemotherapeutic agents and may have a role in combinatorial chemotherapeutic regimens for treatment of solid tumors.

Noncardiac chest pain during war

OBJECTIVES

Noncardiac chest pain (NCCP) has emerged as one of the biggest challenges facing military healthcare providers. The objectives of this study are to determine disease burden and diagnostic breakdown of NCCP, and to identify factors associated with return-to-duty (RTD).

METHODS

Data were prospectively collected from the Deployed Warrior Medical Management Center in Germany on 1935 service and nonservice members medically evacuated out of Operations Iraqi and Enduring Freedom for a primary diagnosis of NCCP between 2004 and 2007. Electronic medical records were reviewed to examine the effect myriad factors had on RTD.

RESULTS

One thousand nine hundred thirty-five personnel were medically evacuated with a diagnosis of NCCP, of whom 92% were men, 70% were in the Army, and 79% sustained their injury in Iraq. Fifty-eight percent returned to duty. The most common causes were musculoskeletal (23.4%), unknown (23%), cardiac (21%), pulmonary (13.9%), and gastrointestinal (11.9%). Factors associated with a positive outcome were being a commissioned officer [adjusted odds ratio (OR) 1.87, P=0.009]; serving in the navy (OR 2.25, P=0.051); having a noncardiac etiology, including gastrointestinal (adjusted OR 5.65, P<0.001), musculoskeletal (OR 4.19, P<0.001), pulmonary (OR 1.80, P=0.018), psychiatric (OR 2.11, P=0.040), or neuropathic (OR 5.05, P=0.040) causes; smoking history (OR 1.54, P=0.005); and receiving no treatment for chest pain (OR 2.17, P=0.006). Covariates associated with a decreased likelihood of RTD were service in Iraq (OR 0.68, P=0.029) and treatment with opioids (OR 0.59, P=0.006) or adjuvants (OR 0.61, P=0.026).

CONCLUSIONS

NCCP represents a significant cause of soldier attrition during combat operations, but is associated with the highest RTD rate among any diagnostic category. Among various causes, gastrointestinal is associated with the highest RTD rate.

PRIMA-1Met/APR-246 induces apoptosis and tumor growth delay in small cell lung cancer expressing mutant p53

PURPOSE

Small cell lung cancer (SCLC) is a highly malignant disease with poor prognosis, necessitating the need to develop new and efficient treatment modalities. PRIMA-1(Met) (p53-dependent reactivation of massive apoptosis), also known as APR-246, is a small molecule, which restores tumor suppressor function to mutant p53 and induces cancer cell death in various cancer types. Since p53 is mutated in more than 90% of SCLC, we investigated the ability of PRIMA-1(Met) to induce apoptosis and inhibit tumor growth in SCLC with different p53 mutations.

EXPERIMENTAL DESIGN

The therapeutic effect of PRIMA-1(Met)/APR-246 was studied in SCLC cells in vitro using cell viability assay, fluorescence-activated cell-sorting analysis, p53 knockdown studies, and Western blot analyses. The antitumor potential of PRIMA-1(Met)/APR-246 was further evaluated in two different SCLC xenograft models.

RESULTS

PRIMA-1(Met)/APR-246 efficiently inhibited the growth of the SCLC cell lines expressing mutant p53 in vitro and induced apoptosis, associated with increased fraction of cells with fragmented DNA, caspase-3 activation, PARP cleavage, Bax and Noxa upregulation and Bcl-2 downregulation in the cells. The growth suppressive effect of PRIMA-1(Met)/APR-246 was markedly reduced in SCLC cell lines transfected with p53 siRNA, supporting the role of mutant p53 in PRIMA-1(Met)/APR-246-induced cell death. Moreover, in vivo studies showed significant antitumor effects of PRIMA-1(Met) after i.v. injection in SCLC mouse models with no apparent toxicity.

CONCLUSION

This study is the first to show the potential use of p53-reactivating molecules such as PRIMA-1(Met)/APR-246 for the treatment of SCLC.

DNA copy number aberrations in small-cell lung cancer reveal activation of the focal adhesion pathway

Small-cell lung cancer (SCLC) is the most aggressive subtype of lung cancer in its clinical behavior, with a 5-year overall survival as low as 5%. Despite years of research in the field, molecular determinants of SCLC behavior are still poorly understood, and this deficiency has translated into an absence of specific diagnostics and targeted therapeutics. We hypothesized that tumor DNA copy number alterations would allow the identification of molecular pathways involved in SCLC progression. Array comparative genomic hybridization was performed on DNA extracted from 46 formalin-fixed paraffin-embedded SCLC tissue specimens. Genomic profiling of tumor and sex-matched control DNA allowed the identification of 70 regions of copy number gain and 55 regions of copy number loss. Using molecular pathway analysis, we found a strong enrichment in these regions of copy number alterations for 11 genes associated with the focal adhesion pathway. We verified these findings at the genomic, gene expression and protein level. Focal Adhesion Kinase (FAK), one of the central genes represented in this pathway, was commonly expressed in SCLC tumors and constitutively phosphorylated in SCLC cell lines. Those were poorly adherent to most substrates but not to laminin-322. Inhibition of FAK phosphorylation at Tyr(397) by a small-molecule inhibitor, PF-573,228, induced a dose-dependent decrease of adhesion and an increase of spreading in SCLC cell lines on laminin-322. Cells that tended to spread also showed a decrease in focal adhesions, as demonstrated by a decreased vinculin expression. These results support the concept that pathway analysis of genes in regions of copy number alterations may uncover molecular mechanisms of disease progression and demonstrate a new role of FAK and associated adhesion pathways in SCLC. Further investigations of FAK at the functional level may lead to a better understanding of SCLC progression and may have therapeutic implications.

Concurrent decline of several antioxidants and markers of oxidative stress during combination chemotherapy for small cell lung cancer

OBJECTIVES

To investigate the oxidant effects of adriamycin-containing chemotherapy (CT), we evaluated various antioxidants, total antioxidant capacity (TRAP) and different parameters of oxidative and nitrosative stress during combination CT.

DESIGN AND METHODS

Blood samples were obtained from 16 small cell lung cancer patients at baseline and several times during the first, second and sixth CT cycles.

RESULTS

There were significant decreases in serum urate and serum proteins during all cycles, serum TRAP during the first two cycles, plasma ascorbic acid and serum TBARS during the first cycle, and serum conjugated dienes and plasma alphatocopherol during the last cycle. The baseline levels of tocopherols increased significantly between the first and sixth CT cycles. Higher levels of baseline plasma thiols were associated with better overall survival (p=0.008).

CONCLUSIONS

Adriamycin-containing CT causes significant oxidative stress as implied by reduced levels of protective antioxidants. Long-term CT treatment seems to enhance lipid peroxidation.

Prognostic factors in patients with small cell lung carcinoma

BACKGROUND

The current prognosis in patients with small cell lung cancer (SCLC) is unsatisfactory, even though there have been considerable improvements in diagnosis and treatment.

METHODS

We retrospectively analyzed all consecutive patients with small cell lung carcinoma between 1995 and 2007 in a Turkish chest hospital. A total of 116 SCLC patients initially presented with limited disease, while 92 small cell lung carcinoma patients were found to be extensive.

RESULTS

The mean age of the patients (18 women and 190 men) was 56 years. The median survival was 74 weeks. Performance status, superior vena cava syndrome (SVCS), stage, elevated white blood cell count, elevated lactate dehidrogenase levels, short symptom duration (<or=4 weeks) response to chemotherapy and bone metastasis were significant prognostic factors in univariate analysis. It was necessary for patients to receive at least three cycles of chemotherapy for a survival benefit. Cox proportional hazards model identified only stage, performance status and SVCS as independent prognostic factors.

CONCLUSIONS

Stage, performance status and SVCS were determined to be the most important prognostic factors for SCLC patients.

Genetic changes in small cell lung carcinoma

Small cell lung carcinoma (SCLC) accounts for approximately 15% of all lung cancer cases. Despite a frequently good response to first-line treatment with chemotherapy and/or radiotherapy, early relapse occurs in the majority of patients and 5-year survival is only about 5%. Therefore, there is a need to develop novel treatments to improve the outcome of patients with SCLC. To fulfil this need, it is critical to gain further understanding on the molecular basis of SCLC and specifically to identify novel therapeutic targets. Clinical trials with molecularly targeted agents have been performed with little success in the past, but recently many promising oncogenic pathways have been discovered and novel targeted therapies are under evaluation. In this review, we summarise the most relevant genetic and signalling pathway alterations reported to date in SCLC and discuss the potential therapeutic implications of such events.

Small-Cell Lung Cancer: An Unusual Therapeutic Approach with More than 10-year Overall Survival. Case Report and Review of the Literature

Small-cell lung cancer is the most aggressive lung cancer, with a dismal prognosis. The authors present a case report of a patient with limited-stage small-cell lung cancer who underwent a thoracotomy for diagnostic purposes, with the diagnosis being made after surgical excision. Combination chemotherapy remains the cornerstone of treatment for both limited and extensive disease. Radiotherapy has been established as an adjunct to chemotherapy in limited-stage disease, while in extensive-stage disease it is mostly reserved for the treatment of brain metastases. As for surgery, the potential benefits of resection are predominantly seen in patients who present with a solitary pulmonary nodule. Since small-cell lung cancer becomes highly resistant to chemotherapy, second-line chemotherapeutic schemes are used for disease progression, with topotecan being the highlighted agent. Despite the unusual therapeutic approach, where surgery was preferred over the standard diagnostic and staging procedures, the patient's more than ten years’ survival makes this case presentation a very interesting one.

[Small cell lung cancer]

With about 20% of all lung cancers small cell lung cancer (SCLC) represents a major subset of this entity. Although therapeutic improvements did not receive as much attention as in non small cell lung cancer (NSCLC), many small steps of clinical progress have been achieved within the last 20 years. An optimal treatment should be based on an interdisciplinary treatment plan. The standard treatment in localized stages represents combined radiation and chemotherapy. Cisplatin and etoposide are in this concern considered as a gold standard. 3D-planned conformal radiotherapy should start as early as possible and should be applied concomitantly to chemotherapy and in certain cases even in a hyperfractionated treatment protocol. In very early stages surgical resection could be an option in selected cases. In advanced stages a platinum-based doublet offers high response rates. As already established in limited disease prophylactic cranial irradiation is now also indicated in extensive disease in case of any tumor remission. In the second line treatment and in patients with reduced performance status topotecan is recommended. Similar as in NSCLC pemetrexed might become an alternative treatment option in the second line setting. In the field of new targeted therapies bevacizumab achieved the most promising results. The present review highlights historical milestones and up-to-date trends in radiotherapy, chemotherapy and surgery. Furthermore, the role of experimental strategies and the management of certain special clinical situations are discussed.

Tumor suppressor role of Notch-1 signaling in neuroendocrine tumors

A growing body of literature is demonstrating that Notch signaling is a more complex process than originally thought. Contradictory findings of notch-1 acting as an oncogene or a tumor suppressor revealed that its role is very specific to the cellular context. In this review we focus on the tumor suppressor role of Notch-1 signaling in neuroendocrine tumors (NETs) such as carcinoid and medullary thyroid cancers. NETs secrete various bioactive hormones that can cause debilitating symptoms. Surgery is the only potential curative treatment for the patients with NETs. Notch-1 signaling is absent in these tumors and activation of Notch-1 significantly reduces tumor growth in vitro. Therefore, identification of compound(s) that activate the Notch-1 pathway in NETs could be a potential strategy to treat patients with NETs.

D2 dopamine receptor-mediated antiproliferation in a small cell lung cancer cell line, NCI-H69

The D2 dopamine receptor agonist bromocriptine has been used clinically for reducing tumor mass of pituitary adenomas arising from lactotroph origins. As well, bromocriptine has been shown to have an antiproliferative effect on primary lactotrophs and lactotroph-derived cell lines. The presence of D2 dopamine-like receptors on NCI-H69 cells was previously established by the use of [(125)I]iodosulpride binding and has been confirmed in this study by use of reverse transcription PCR with receptor-specific primers. The reverse transcription PCR analysis of NCI-H69 cells demonstrates that both the D2s and D2l are expressed in NCI-H69 cells, with D2s having the higher relative expression. The activation of the D2R results in an inhibition of growth of NCI-H69 cells as assessed by the incorporation of [(3)H]thymidine; a process not sensitive to pertussis toxin. In NCI-H69 cells, the D2 dopamine-like receptor is coupled to the inhibition of forskolin-stimulated cAMP accumulation and to the stimulation of phospholipase D. The receptor-mediated inhibition of cAMP accumulation is ablated by overnight treatment with pertussis toxin but the stimulation of phospholipase D mediated by dopaminergic agonists is not. These data suggest that the phospholipase D pathway is responsible for the antiproliferative effects of D2 dopamine-like receptors agonists in small cell lung cancer cells. In support of this hypothesis, the inhibition of [(3)H]thymidine incorporation mediated by dopaminergic agonists was shown to be sensitive to the presence of ethanol. Taken together, these data suggest that the D2 dopamine-like receptor activates phospholipase D, which ultimately leads to an inhibition of growth of this small cell lung cancer cell line.

Lung cancer: Future directions

Increasingly, basic research is being translated into clinical benefits for patients. Recent studies have shed more light on the clinical use of targeted therapies such as tyrosine kinase and angiogenesis inhibitors, and predictive factors for their clinical benefit and their role in different clinical settings are now being elucidated. New insights into the basic biology of lung cancer hold translational promise in risk assessment, early detection, molecular staging, treatment response prediction and novel therapies. New targeted agents directed at apoptotic and developmental pathways have the potential to exploit newly discovered vulnerabilities in the basic machinery of cancer. In addition, exploration of the cancer stem cell phenomenon in lung cancer may generate new approaches to prevent recurrence in surgically respectable lung cancer, and for the long-term control of extensive disease. Molecular profiling may also allow for highly individualized prognostic, predictive and therapeutic treatment plans tailored for each patient based on the molecular diagnostic profile of their tumour. Advances in genetic susceptibility, early detection and individualized therapy based on each tumour's unique biological properties all hold promise for the future management of lung cancer.

Targeting mTOR signaling in lung cancer

Lung cancer is the leading cause of cancer-related mortality in the world, with more than 1 million deaths per year. Over the past years, lung cancer treatment has been based on cytotoxic agents and an improvement in the outcome and quality of life for patients has been observed. However, it has become clear that additional therapeutic strategies are urgently required in order to provide an improved survival benefit for patients. Two major intracellular signaling pathways, the Ras/Raf/extracellular signal-regulated kinase (Erk) and the phosphoinositide 3-kinase (PI3K)/Akt pathways have been extensively studied in neoplasia, including lung cancer. Furthermore, the study of constitutively activated receptor tyrosine kinases (RTKs) and their downstream signaling mediators has opened a promising new field of investigation for lung cancer treatment. Since both the Ras/Raf/Erk and the PI3K/Akt pathways are downstream of a plethora of activated RTKs, they have been extensively studied for the development of novel anti-tumor agents. Moreover, the mammalian target of rapamycin (mTOR) has been identified as a downstream target of the PI3K/Akt pathway. Rapamycin and its derivatives are highly selective and very potent inhibitors of mTOR and initial pre-clinical and clinical studies have reported encouraging results for different tumor types. Nevertheless for lung cancer, this approach has not been successful yet. Here we will review the molecular basis of PI3K/Akt/mTOR signaling in lung cancer and further discuss the therapeutic potential of multi-targeted strategies involving mTOR inhibitors.