Against Lung Cancer Cells: To Be, or Not to Be, That Is the Problem

Abstract

Tobacco smoke and radioactive radon gas impose a high risk for lung cancer. The radon-derived ionizing radiation and some components of cigarette smoke induce oxidative stress by generating reactive oxygen species (ROS). Respiratory lung cells are subject to the ROS that causes DNA breaks, which subsequently bring about DNA mutagenesis and are intimately linked with carcinogenesis. The damaged cells by oxidative stress are often destroyed through the active apoptotic pathway. However, the ROS also perform critical signaling functions in stress responses, cell survival, and cell proliferation. Some molecules enhance radiation-induced tumor cell killing via the reduction in DNA repair levels. Hence the DNA repair levels may be a novel therapeutic modality in overcoming drug resistance in lung cancer. Either survival or apoptosis, which is determined by the balance between DNA damage and DNA repair levels, may lender the major problems in cancer therapy. The purpose of this paper is to take a closer look at risk factor and at therapy modulation factor in lung cancer relevant to the ROS.

The Assessment of Cancer-Related Fatigue Syndrome in Patients with Lung Cancer during Palliative Chemotherapy

“…It is therefore important to ensure them the highest quality of life. Overall prognosis is poor because only 10% of patients survive one year [6]. Survival period after the application of palliative chemotherapy has increased slightly from 7.9 to 11.3 months [6].…”

Chemical Composition, Antioxidant, Anticancer Properties and Toxicity Evaluation of Leaf Essential Oil of <i>Cupressus sempervirens</i>

“…Chen et al (1998) suggested that the anticancer activity of limonene might be related to inhibition of the membrane association of P21ras protein and increased gap junction intercellular communication. An additional recent study indicated that terpinolene reduced the protein expression of AKT1 in K562 human leukemic cells and inhibited cell proliferation (Okumura et al, 2012). In contrast, Sobral et al (2014) reviewed that camphor, 4-terpineol, γ-terpinene, 1,8-cineole and myrcene which found in small quantity in Cypress essential oil under investigation in this study had antitumor activity against several human, mouse and rat cancer cell lines with different mechanisms such induction of apoptosis and inhibition of the NF-κB pathway.…”

Roles of Estrogens in Prostate Cancer Development via the Modulation of DNA-Repair System

“…It has been shown that inactivation of ATM is a critical step in genomic instability and the prostate carcinogenesis [56]. One of the additional consequences of defective DNA repair is cellular hyper-sensitivity to DNA damaging agents [57]. The p53 is an important transcription factor which regulates lots of genes and protects against genomic instability.…”

“…Suppression of DNA repair pathway seems to obstruct the mechanisms that are essential for cell survival, especially when in a presence of oncogenic mutations. Hence, DNA damaging agents work well in cancer cells with DNA repair defects for therapeutic sense [57]. Epigenetic mechanisms such as histone modifications and/or DNA methylation have also been evaluated with an understanding for improving cancer therapy via the regulation of genes-expression involved in DNA repair [68].…”