Genome-wide gene expression analysis of chemoresistant pulmonary carcinoid cells

Exploring the multifaceted antitumor activity of axitinib in lung carcinoids

Introduction

Lung carcinoids (LCs) are a type of neuroendocrine tumor (NET) that originate in the bronchopulmonary tract. LCs account for 20-25% of all NETs and approximately 1-2% of lung cancers. Given the highly vascularized nature of NETs and their tendency to overexpress vascular growth factor receptors (VEGFR), inhibiting angiogenesis appears as a potential therapeutic target in slowing down tumor growth and spread. This study evaluated the long-term antitumor activity and related mechanisms of axitinib (AXI), a VEGFR-targeting drug, in LC cell lines.

Methods

Three LC cell lines (NCI-H727, UMC-11 and NCI-H835) were incubated with their respective EC50 AXI concentrations for 6 days. At the end of the incubation, FACS experiments and Western blot analyses were performed to examine changes in the cell cycle and the activation of apoptosis. Microscopy analyses were added to describe the mechanisms of senescence and mitotic catastrophe when present.

Results

The primary effect of AXI on LC cell lines is to arrest tumor growth through an indirect DNA damage. Notably, AXI triggers this response in diverse manners among the cell lines, such as inducing senescence or mitotic catastrophe. The drug seems to lose its efficacy when the DNA damage is mitigated, as observed in NCI-H835 cells.

Conclusion

The ability of AXI to affect cell viability and proliferation in LC tumor cells highlights its potential as a therapeutic agent. The role of DNA damage and the consequent activation of senescence seem to be a prerequisite for AXI to exert its function.

Pancreatic metastasis from mixed adenoneuroendocrine carcinoma of the uterine cervix: a case report

Metastatic cancers of the pancreas are rare, accounting for approximately 2-4% of all pancreatic malignancies. Renal cell carcinoma is the most common solid tumor that metastasizes to the pancreas. Here, we present a case of uterine cervical carcinoma metastasizing to the pancreas and review the literature regarding this rare event. A 44-year-old woman with a uterine cervical tumor had undergone radical hysterectomy and had been diagnosed pathologically with stage Ib mixed adenoneuroendocrine carcinoma in 2004. She underwent concurrent radiotherapy and chemotherapy postoperatively. Pulmonary metastases subsequently appeared in 2008 and 2011, and she underwent complete resection of the lung tumors by video-assisted thoracic surgery. Although she was followed up without any treatment and with no other recurrences, positron emission tomography revealed an area of abnormal uptake within the pancreatic body in 2012. Enhanced computed tomography demonstrated a 20-mm lesion in the pancreatic body and upstream pancreatic duct dilatation. Endoscopic ultrasonography-guided fine needle aspiration was performed and pathological examination suggested neuroendocrine carcinoma (NEC). On the basis of these results and the patient's oncological background, lesions in the pancreatic body were diagnosed as secondary metastasis from the cervical carcinoma that had been treated 8 years earlier. No other distant metastases were visualized, and the patient subsequently underwent middle pancreatectomy. Pathological examination showed NEC consistent with pancreatic metastasis from the uterine cervical carcinoma. The patient has survived 7 months since the middle pancreatectomy without any signs of local recurrence or other metastatic lesions.

Overexpression of CYP3A4 in a COLO 205 Colon Cancer Stem Cell Model in vitro

Cancer stem cells (CSCs) seem to constitute a subpopulation of tumor cells that escape from chemotherapy and cause recurrent disease. Low proliferation rates, protection in a stem cell niche and overexpression of drug resistance proteins are considered to confer chemoresistance. We established an in vitro colon CSC-like model using the COLO 205 cell line, which revealed transiently increased expression of CD133 when transferred to serum-free stem cell culture medium. Assessment of global gene expression of COLO 205 cells under these conditions identified a set of upregulated genes including cytochrome P450 3A4 (CYP3A4) and aldehyde dehydrogenase 1A1 (ALDH1A1), as confirmed by real-time qPCR. ALDH1A1 is a CSC marker for certain tumor entities and confers resistance to cyclophosphamide. CYP3A4 is expressed in liver and colon and its overexpression seems particularly relevant in colon cancer, since it inactivates irinotecan and other xenobiotics, such as taxols and vinca alkaloids. In conclusion, this COLO 205 model provides evidence for CD133 induction concomitant with overexpression of CYP3A4, which, together with ATP-binding cassette, subfamily G, member 2 (ABCG2) and others, may have a role in chemoresistant colon CSCs and a negative impact on disease-free survival in colon cancer patients.