Curcumin induces mitochondria pathway mediated cell apoptosis in A549 lung adenocarcinoma cells

Abstract

Abstract.Several studies have shown that curcumin can induce apoptosis and inhibit growth in human tumor cell lines. However, the mechanism is not completely understood yet. The present studies were designed to investigate the effects of curcumin on human A549 lung adenocarcinoma cells lines to better understand its effect on apoptosis and apoptosis-related genes in vitro. Apoptosis induction, mitochondria membrane potential, mitochondria structure, and apoptotic associated gene expression were examined by flow cytometric assay, confocal microscopy, Western blotting and electron microscopy. After treatment with curcumin, percentage of apoptotic cells increased dose-and timedependently, and morphology observation revealed typical apoptotic features. Our data further indicated that the expression of Bax proteins in A549 cells was increased in a dose-dependent manner, whereas the expression of Bcl-2 was significantly decreased, thus the ratio of Bax/Bcl-2 was increased. The apoptotic process was accompanied by the change of mitochondrial function and structure which led to release of the cytochrome c, and activation of caspase-9 and caspase-3. Furthermore, curcumin also induced a dosedependent cleavage of PARP. Caspases activation during the course of curcumin-induced apoptosis was additionally confirmed by using a broad-spectrum caspases inhibitor, Z-VAD-fmk. As expected, the inhibitor was able to decrease curcumin-induced apoptosis on A549 cells. These results suggested that mitochondria played an important role in the curcumin-induced apoptosis, and mitochondria membrane potential loss initiated apoptosis via the activation of caspases.

Synergistic anticancer activity of curcumin and bleomycin: An in�vitro study using human malignant testicular germ cells

“…We found that curcumin induced caspasedependent apoptotic signaling pathways, accompanied by a decreased Bcl-2 expression and increased Bax and Cyt-c levels in NT2 cell lines. Similar to our findings, several studies have reported that curcumin decreased Bcl-2 levels in many types of cancer cells, such as squamous cell carcinoma (18), small cell lung cancer (19), myeloid leukemia (20) and adenocarcinoma cells (21). Our results are consistent with those from other reports of curcumin-mediated cytotoxic activity via the induction of apoptosis (22).…”

Luteolin Induced-growth Inhibition and Apoptosis of Human Esophageal Squamous Carcinoma Cell Line Eca109 Cells in vitro

“…Luteolin inhibits the proliferation of many types of cancer cells through regulating the cell cycle (Fotsis et al, 1997;Knowles et al, 2000;Ong et al, 2010;Cai et al, 2011). Moreover, luteolin also could induce tumor cells apoptosis including epidermoid carcinoma, leukemia, pancreatic tumor, lung cancer and hepatoma (Huang et al, 1999;Lee et al, 2002;Cheng et al, 2005;Lee et al, 2005;Chen et al, 2012). However, the vitro experiment of luteolin affected on human esophageal cancer cell line has not been intensely investigated.…”

Curcumin Conjugates Induce Apoptosis Via a Mitochondrion Dependent Pathway in MCF-7 and MDA-MB-231 Cell Lines

“…Bax and Bak induce apoptosis in cells. Hence the ratio antiapoptotic vs apoptotic protein is important to lead the way of mitochondrial dependent apoptosis (Chen et al, 2010;Kunwar et al, 2012). Bax translocates to mitochondria and leads to membrane permeabilization.…”