F508 amino acid deletion mutation of CFTR gene in Korean lung cancer patients

Is cellular senescence involved in cystic fibrosis?

Pulmonary disease is the main cause of the morbidity and mortality of patients affected by cystic fibrosis (CF). The lung pathology is dominated by excessive recruitment of neutrophils followed by an exaggerated inflammatory process that has also been reported to occur in the absence of apparent pathogenic infections. Airway surface dehydration and mucus accumulation are the driving forces of this process. The continuous release of reactive oxygen species and proteases by neutrophils contributes to tissue damage, which eventually leads to respiratory insufficiency. CF has been considered a paediatric problem for several decades. Nevertheless, during the last 40 years, therapeutic options for CF have been greatly improved, turning CF into a chronic disease and extending the life expectancy of patients. Unfortunately, chronic inflammatory processes, which are characterized by a substantial release of cytokines and chemokines, along with ROS and proteases, can accelerate cellular senescence, leading to further complications in adulthood. The alterations and mechanisms downstream of CFTR functional defects that can stimulate cellular senescence remain unclear. However, while there are correlative data suggesting that cellular senescence may be implicated in CF, a causal or consequential relationship between cellular senescence and CF is still far from being established. Senescence can be both beneficial and detrimental. Senescence may suppress bacterial infections and cooperate with tissue repair. Additionally, it may act as an effective anticancer mechanism. However, it may also promote a pro-inflammatory environment, thereby damaging tissues and leading to chronic age-related diseases. In this review, we present the most current knowledge on cellular senescence and contextualize its possible involvement in CF.

Cystic fibrosis transmembrane conductance regulator-emerging regulator of cancer

Mutations of cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis, the most common life-limiting recessive genetic disease among Caucasians. CFTR mutations have also been linked to increased risk of various cancers but remained controversial for a long time. Recent studies have begun to reveal that CFTR is not merely an ion channel but also an important regulator of cancer development and progression with multiple signaling pathways identified. In this review, we will first present clinical findings showing the correlation of genetic mutations or aberrant expression of CFTR with cancer incidence in multiple cancers. We will then focus on the roles of CFTR in fundamental cellular processes including transformation, survival, proliferation, migration, invasion and epithelial-mesenchymal transition in cancer cells, highlighting the signaling pathways involved. Finally, the association of CFTR expression levels with patient prognosis, and the potential of CFTR as a cancer prognosis indicator in human malignancies will be discussed.

Emerging role of cystic fibrosis transmembrane conductance regulator - an epithelial chloride channel in gastrointestinal cancers

Cystic fibrosis transmembrane conductance regulator (CFTR), a glycoprotein with 1480 amino acids, has been well established as a chloride channel mainly expressed in the epithelial cells of various tissues and organs such as lungs, sweat glands, gastrointestinal system, and reproductive organs. Although defective CFTR leads to cystic fibrosis, a common genetic disorder in the Caucasian population, there is accumulating evidence that suggests a novel role of CFTR in various cancers, especially in gastroenterological cancers, such as pancreatic cancer and colon cancer. In this review, we summarize the emerging findings that link CFTR with various cancers, with focus on the association between CFTR defects and gastrointestinal cancers as well as the underlying mechanisms. Further study of CFTR in cancer biology may help pave a new way for the diagnosis and treatment of gastrointestinal cancers.

Weighted gene co-expression network analysis of pneumocytes under exposure to a carcinogenic dose of chloroprene

AIMS

Occupational exposure to chloroprene via inhalation may lead to acute toxicity and chronic pulmonary diseases, including lung cancer. Currently, most research is focused on epidemiological studies of chloroprene production workers. The specific molecular mechanism of carcinogenesis by chloroprene in lung tissues still remains obscure, and specific candidate therapeutic targets for lung cancer are lacking. The present study identifies specific gene modules and valuable hubs associated with lung cancer.

MAIN METHODS

We downloaded the dataset GSE40795 from the Gene Expression Omnibus (GEO) and divided the dataset into the non-carcinogenic dose chloroprene exposed mice group and the carcinogenic dose chloroprene exposed mice group. With a systemic biological view, we discovered significantly altered gene modules between the two groups and identified hub genes in the carcinogenic dose exposed group using weighted co-expression network analysis (WGCNA).

KEY FINDINGS

A total of 2434 differentially expressed genes were identified. Twelve gene modules with multiple biological activities were related to the carcinogenesis of chloroprene in lung tissue. Seven hub genes that were critical for the carcinogenesis of chloroprene in lung tissue were ultimately identified, including Cftr, Hip1, Tbl1x, Ephx1, Cbr3, Antxr2 and Ccnd2. They were implicated in inflammatory response, cell transformation, gene transcription regulation, phase II detoxification, angiogenesis, cell adhesion, motility and the cell cycle.

SIGNIFICANCE

The seven hub genes may become valuable candidates for risk assessment biomarkers and therapeutic targets in lung cancer.

Cystic fibrosis transmembrane conductance regulator (CFTR) gene 5T allele may protect against prostate cancer: a case-control study in Chinese Han population

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in a wide variety of epithelial cells including the prostate subglandular epithelia. Previous studies have suggested that CFTR mutations and polymorphisms may be associated with several cancers. Mutations and polymorphisms in the CFTR gene are responsible for cystic fibrosis (CF), and the incidence of prostate cancer in CF patients seemed to be lower than expected.

METHODS

A hospital-based case-control study was conducted including 230 prostate cancer patients and 230 age-matched controls. We used nested PCR to analysis the IVS8-poly(T) tract and PCR-RFLP method to analysis the M470V polymorphism in CFTR gene.

RESULTS

We observed an association of the low expression allele, IVS8-5T with prostate cancer protection (P=0.002; OR=0.281, 95%CI 0.120-0.658). Logistic regression analysis confirmed the 5T/7T genotype was in protective association with prostate cancer risk (P=0.003; OR=0.232, 95%CI 0.090-0.599). Linkage disequilibrium between IVS8-poly(T) and M470V existed among prostate cancer patients (D'=0.701). The low expression haplotype, "5T-V470" was found to be associated with protection against prostate cancer risk (P=0.010; OR=0.324, 95%CI 0.132-0.796).

CONCLUSIONS

Our results indicate that the low expression CFTR polymorphisms may contribute to a reduced risk of prostate cancer in Chinese Han population.

Report of a Korean patient with cystic fibrosis, carrying Q98R and Q220X mutations in the CFTR gene

Although cystic fibrosis (CF) is one of the most frequently seen autosomal-recessive disorders in Caucasians, it is extremely rare in the Korean population. Recently, a 15-yr-old Korean boy was admitted to our hospital complaining of coughing, sputum, and exertional dyspnea. Chest radiographs and computed tomographic chest and paranasal sinus scans revealed diffuse bronchiectasis and pansinusitis. Pulmonary function tests revealed severe obstructive impairment. The average sweat chloride concentrations on both of the patients' forearms were 63.0 mM/L (reference limit: < 40 mM/L). Upon mutation analysis, two different mutations (Q98R and Q220X) were identified in the cystic fibrosis transmembrane conductance regulator gene, both of which had been previously detected in CF patients, one from France and the other from England. As CF is quite rare in Korea, the diagnosis of CF in this patient might be delayed. Therefore, we recommend that a diagnosis of CF should be suspected in patients exhibiting unexplained chronic respiratory symptoms.