Dutch Statistics on Lung Cancer: Sobering Experience for a New Approach

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.

miR-193a-3p inhibition of the Slug activator PAK4 suppresses non-small cell lung cancer aggressiveness via the p53/Slug/L1CAM pathway

L1 cell adhesion molecule (L1CAM) promotes invasiveness and metastasis in non-small cell lung cancer (NSCLC) cells and is upregulated by the p53-regulated transcription factor Slug. p21-activated kinase 4 (PAK4) directly phosphorylates Slug, resulting in pro-malignant Slug stabilization. We hypothesized that microRNA-based negative regulation of PAK4 would reduce L1CAM-induced NSCLC aggressiveness via destabilizing Slug. We found that elevated L1CAM expression was tightly correlated with p53 loss-of-function and reduced NSCLC patient survival. L1CAM suppression reduced NSCLC cell migration and invasiveness in vitro as well as tumor formation and distal metastasis in vivo. Mechanistically, p53 restricts L1CAM expression through the β-catenin/Slug pathway, with levels of β-catenin and Slug positively correlating with L1CAM expression in NSCLC tumors. The microRNA miR-193a-3p directly targets PAK4 and suppresses downstream p-Slug and L1CAM expression. Silencing PAK4, Slug, and L1CAM mirrored miR-193a-3p's effects upon the migration and invasiveness of NSCLC cells in vitro. Decreased miR-193a-3p levels correlated with elevated PAK4, p-Slug, and L1CAM levels in NSCLC tumors. Our findings support a model of miR-193a-3p as a suppressor of metastatic disease progression in NSCLC via modulation of the p53/Slug/L1CAM pathway.

CDK16 overexpressed in non-small cell lung cancer and regulates cancer cell growth and apoptosis via a p27-dependent mechanism

Cyclin-dependent kinase 16 (CDK16, PCTAIRE1) expression is upregulated in a wide variety of human malignancies. However, the function(s) of CDK16 in non-small cell lung cancer (NSCLC) remain unknown. Therefore, here we investigated the role of CDK16 in NSCLC. From 43 NSCLC tumors and matching healthy control lung tissues, immunohistochemistry revealed significantly greater CDK16 and phospho-p27^Ser10 staining levels in NSCLC samples relative to healthy controls. The NSCLC cell line EKVX was transfected with a control siRNA, a CDK16-siRNA, or CDK16-siRNA + p27-siRNA. We found significantly decreased proliferation levels and significantly increased apoptosis levels in CDK16-silenced NSCLC cells. However, these effects were abrogated in cells treated with both the CDK16-siRNA and the p27-siRNA. In CDK16-silenced NSCLC cells, we found upregulated p27 and downregulated phospho-p27^Ser10 protein expression but downregulated ubiquitinated p27 and ubiquitinated phospho-p27^Ser10 protein expression. Cycloheximide-treated CDK16-silenced NSCLC cells displayed a much milder reduction in p27 protein expression over time relative to untreated CDK16-silenced NSCLC cells. In summary, CDK16 is significantly upregulated in human NSCLC tumor tissue and plays an oncogenic role in NSCLC cells via promoting cell proliferation and inhibiting apoptosis in a p27-dependent manner. Moreover, CDK16 negatively regulates expression of the p27 via ubiquination and protein degradation.

Targeting the Wnt-Regulatory Protein CTNNBIP1 by microRNA-214 Enhances the Stemness and Self-Renewal of Cancer Stem-Like Cells in Lung Adenocarcinomas

A novel hypothesis in cancer biology proposes that cancer growth is driven by cancer stem-like cells (CSLCs), also called tumor-initiating cells, which can self-renew and differentiate into multilineage progeny in a fashion similar to stem cells. However, the impact and underlying mechanisms of this process in lung adenocarcinoma (LAC) remain to be elucidated. Here, we report that microRNA-214 (miR-214) contributes to cell self-renewal by directly targeting catenin beta interacting protein 1 (CTNNBIP1), a member of the Wnt signaling pathway. We demonstrate that miR-214 overexpression enhances stem-like properties in LAC cells and that miR-214 shows increased expression in CSLCs derived from primary tumor tissue and from two LAC cell lines (A549 and NCI-H1650). Strikingly, downregulation of miR-214 expression in CSLCs resulted in a significant decrease in spheroid formation and the expression of the stem-cell markers Nanog, Oct-4, and Sox-2. Finally, CTNNBIP1 was identified as a target of miR-214. miR-214 expression in LAC was negatively correlated with CTNNBIP1 expression and positively correlated with differentiated cellular states. Moreover, CTNNBIP1 expression correlated with longer overall survival in LAC patients. This study reveals that miR-214 plays a critical role in CSLC self-renewal and stemness by targeting CTNNBIP1. The identification of this functional miR-214-CTNNBIP1 interaction that regulates self-renewal in CSLCs has the potential to direct the development of novel therapeutic strategies for LAC.

Concurrent chemoradiotherapy for large-volume locally-advanced non-small cell lung cancer

PURPOSE

Patients with large volume stage III non-small cell lung cancer (NSCLC) are often excluded from concurrent chemoradiotherapy (CRT) protocols due to fears about excessive toxicity and poor survival. Patients with N3 nodal disease may be excluded for the same reason. We have routinely accepted fit patients in both the above groups for CRT if they met our planning parameters. We analyzed toxicity and survival outcomes for patients undergoing CRT with a planning target volume (PTV) exceeding 700 cc, either with or without N3 nodal disease, or a PTV less then 700 cc with N3 disease.

MATERIALS AND METHODS

Single center, retrospective study of patients with stage III NSCLC treated with CRT between 2004 and 2011.

RESULTS

121 patients were eligible, with 81% (98/121) having a PTV>700 cc (of whom 33% (32/98) had N3 nodal disease) and 19% (23/121) having N3 disease and a PTV≤700 cc. Grade ≥3 esophagitis and pneumonitis were recorded in respectively 34% and 4% of all patients. Median follow-up for all patients was 37.6 months (mo). Median overall (OS) and progression-free (PFS) survivals were 15.7 mo and 11.6 mo, respectively, OS for all patients with PTV>700 cc was 14.5 mo (19.5 mo with N3 and 13.2 mo without N3), compared to 26.5 mo for PTV≤700 cc with N3 (p=0.009). About 1 in 4 patients with PTV>700 cc died within 6 mo of starting radiotherapy (this was associated with Charlson comorbidity index [CCI]≥1), while about 18% were alive at 3 years.

CONCLUSION

Patients undergoing CRT for stage III NSCLC with a PTV>700 cc, with or without N3 nodal disease, had a significantly shorter OS than patients with PTV≤700 cc with N3. Patients with PTV>700 cc and with CCI≥1, had a significantly higher risk of early death but longer-term survivors with PTV>700 cc are observed. The PTV and CCI should be considered in clinical decision making and used as stratification factors in future trials.

Improved survival after introduction of chemotherapy for malignant pleural mesothelioma in Slovenia: Population-based survey of 444 patients

Background

Malignant pleural mesothelioma is a rare tumour with increasing frequency throughout the world. Due to long latency after exposure to asbestos, restrictions in the production and use of asbestos have not yet alleviated the burden of mesothelioma. During the last decade, several trials confirmed the benefit of systemic treatment with drugs such as doublets with cisplatina and gemcitabine or pemetrexed for carefully selected patients in good performance status. The purpose of this survey was to assess the impact of systemic treatment for the whole national population of patients with mesothelioma.

Patients and methods.

A retrospective study included all patients in Slovenia with histologically confirmed diagnosis of malignant pleural mesothelioma in the period from 1974 till 2008. Data from the Cancer Registry of Slovenia were supplemented by review of clinical records of the Institute of Oncology in Ljubljana where virtually all non-surgical treatment for mesothelioma was performed. We analysed the incidence, treatment, and survival of patients treated in the era of infrequent chemotherapy (1974–2003, the first period) and after it (2004–2008, the second period).

Results

The survey included 444 patients, of whom 325 and 119 were diagnosed in the first and second period, respectively. Joinpoint regression analysis showed that after 1995 the trend in crude incidence rates increased more rapidly; the annual change was 0.03 per 100,000 per year before 1995 and 0.06 per 100,000 per year after. There was clear male predominance (70%) throughout the period covered by the survey. The proportion of patients above 65 years of age increased from 41.8% to 54.6% for the first and second period, respectively (p = 0.02). With a total of 52 (11.7%) operated patients, surgical treatment was rare and used only for selected patients with early disease and without comorbidity, leading to their relatively long median survival of 13.6 months. Chemotherapy was applied to 56 (17.2%) and to 96 (80.7%) patients during the first and second period, respectively. While a variety of older drugs were used in the first period, the most common regimen in the second period (applied to 91 patients) was doublet of low-dose gemcitabine in prolonged infusion and cisplatin. For the whole population of patients regardless the mode of treatment, median survival was 7.4 and 12.6 months (p-value = 0.037) for the first and second period, respectively.

Conclusions

Increasing incidence, male predominance and increased proportion of older patients confirm that the burden of mesothelioma persists in spite of a 15-years old ban in the production of asbestos. Modern chemotherapy, and in particular treatment with low-dose gemcitabine in prolonged infusion and cisplatin significantly prolonged median survival of patients with malignant pleural mesothelioma in Slovenia.