Low expression of ERK signaling pathway affecting proliferation, cell cycle arrest and apoptosis of human gastric HGC-27 cells line

Breaking the Barrier of Cancer through Papaya Extract and their Formulation

Background:

In the last decade, many new avenues of cancer treatment have opened up but the costs of treatment have sky-rocketed too. Hence, screening of indigenously available plant and animal resources for anti-carcinogenic potential is an important branch of anticancer research. The effort has been made through this comprehensive review to highlight the recent developments of anticancer therapies using different parts of papaya plant extract.

Methods:

In search of the naturally existing animals and plants for anticarcinogenic potential, papaya plant has been exploited by the scientist working in this research field. A widespread literature search was performed for writing this review.

Results:

Different constituents of Carica papaya responsible for anticancer activities have been discussed. Papaya extract for the treatment of breast, liver, blood, pancreas, skin, prostate, and colon cancer have also been reported. Finally, the various formulation approach using Carica papaya extract have been highlighted.

Conclusion:

The information provided in this review might be useful for researchers in designing of novel formulation of Carica papaya extract for the treatment of cancer.

Lycopene Inhibits Activation of Epidermal Growth Factor Receptor and Expression of Cyclooxygenase-2 in Gastric Cancer Cells

Reactive oxygen species (ROS) contribute to the oncogenic phenotype of cancer cells by acting as signaling molecules for inducing proliferation. ROS are known to activate the epidermal growth factor receptor (EGFR), which causes the activation of the Ras/mitogen-activated protein kinases (MAPKs) pathway. The Ras-dependent pathway promotes the activation of nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-κB), a transcriptional modulator of cyclooxygenase-2 (COX-2) that induces cell proliferation. Lycopene is a potent antioxidant carotenoid and is responsible for the red color of fruits and vegetables. This study aims to investigate whether lycopene inhibits proliferation and induces apoptosis in gastric cancer AGS cells by suppressing the EGFR/Ras/MAPK and NF-κB-COX-2 signaling axis. Lycopene decreased cell viability and increased apoptotic indices (DNA fragmentation, apoptosis inducing factor, cleavage of caspase-3 and caspase-9, Bax/Bcl-2 ratio). Lycopene reduced the level of intracellular and mitochondrial ROS and decreased the activation of the ROS-mediated EGFR/Ras/extracellular signal-regulated kinase (ERK) and p38 MAPK pathways, thus leading to attenuation of the DNA-binding activity of NF-κB p50/p50 and the level of COX-2 gene expression. These results show that lycopene-induced apoptosis and inhibition of proliferation occur via inhibition of ROS-activated EGFR/Ras/ERK and p38 MAPK pathways and NF-κB-mediated COX-2 gene expression in AGS cells. In conclusion, consumption of lycopene-enriched foods could decrease the incidence of gastric cancer.

Lycopene treatment inhibits activation of Jak1/Stat3 and Wnt/β-catenin signaling and attenuates hyperproliferation in gastric epithelial cells

Helicobacter pylori (H pylori) colonizes the human stomach and increases the risk of gastric diseases including gastric cancer. H pylori increases reactive oxygen species (ROS), which activate Janus-activator kinase 1 (Jak1)/signal transducers and activators of transcription 3 (Stat3) in gastric epithelial cells. ROS mediate hyperproliferation, a hallmark of carcinogenesis, by activating Wnt/β-catenin signaling in various cells. Lycopene is a potent antioxidant exhibiting anticancer effects. We hypothesized that lycopene may inhibit H pylori-induced hyperproliferation by suppressing ROS-mediated activation of Jak1/Stat3 and Wnt/β-catenin signaling, and β-catenin target gene expression in gastric epithelial cells. We determined cell viability, ROS levels, and the protein levels of phospho- and total Jak1/Stat3, Wnt/β-catenin signaling molecules, Wnt-1, lipoprotein-related protein 5, and β-catenin target oncogenes (c-Myc and cyclin E) in H pylori-infected gastric epithelial AGS cells. The Jak1/Stat3 inhibitor AG490 served as the control treatment. The significance of the differences among groups was calculated using the 1-way analysis of variance followed by Newman-Keuls post hoc tests. The results show that lycopene reduced ROS levels and inhibited Jak1/Stat3 activation, alteration of Wnt/β-catenin multiprotein complex molecules, expression of c-Myc and cyclin E, and cell proliferation in H pylori-infected AGS cells. AG490 similarly inhibited H pylori-induced cell proliferation, alteration of Wnt/β-catenin multiprotein complex molecules, and oncogene expression. H pylori increased the levels of Wnt-1 and its receptor lipoprotein-related protein 5; this increase was inhibited by either lycopene or AG490 in AGS cells. In conclusion, lycopene inhibits ROS-mediated activation of Jak1/Stat3 and Wnt/β-catenin signaling and, thus, oncogene expression in relation to hyperproliferation in H pylori-infected gastric epithelial cells. Lycopene might be a potential and promising nutrient for preventing H pylori-associated gastric diseases including gastric cancer.

ERCC6L, a DNA helicase, is involved in cell proliferation and associated with survival and progress in breast and kidney cancers

By analyzing 4987 cancer transcriptomes from The Cancer Genome Atlas (TCGA), we identified that excision repair cross-complementation group 6 like (ERCC6L), a newly discovered DNA helicase, is highly expressed in 12 solid cancers. However, its role and mechanism in tumorigenesis are largely unknown. In this study, we found that ERCC6L silencing by small interring RNA (siRNA) or short hairpin RNA (shRNA) significantly inhibited the proliferation of breast (MCF-7, MDA-MB-231) and kidney cancer cells (786-0). Furthermore, ERCC6L silencing induced cell cycle arrest at G0/G1 phase without affecting apoptosis. We then performed RNA sequencing (RNA-seq) analysis after ERCC6L silencing and identified that RAB31 was markedly downregulated at both the transcriptional and translational levels. Its downstream protein, phosphorylated MAPK and CDK2 were also inhibited by ERCC6L silencing. The xenograft experiment showed that silencing of ERCC6L strikingly inhibited tumor growth from the 7th day after xenograft in nude mice. In addition, higher ERCC6L expression was found to be significantly associated with worse clinical survival in breast and kidney cancers. In conclusion, our results suggest that ERCC6L may stimulates cancer cell proliferation by promoting cell cycle through a way of RAB31-MAPK-CDK2, and it could be a potential biomarker for cancer prognosis and target for cancer treatment.

Lycopene: Is it Beneficial to Human Health as an Antioxidant?

It is well known that free oxygen radicals play an important role in the pathogenesis of several chronic disorders. Antioxidants are known as potential scavengers of reactive oxygen species that can protect biologic membranes against oxidative damage. Recent interest in phytochemicals has increased because of their protective effects against free oxygen radicals. Lycopene, which belongs to the carotenoid family, is the most effective singlet oxygen scavenger in vitro of all the carotenoids. Foods that contain lycopene and related supplements have been reported to prevent chronic diseases including cancer, asthma, and cardiovascular disorders. The aim of the article was to give a brief review of the antioxidant properties and beneficial health effects of lycopene.

Flux Balance Analysis Inspired Bioprocess Upgrading for Lycopene Production by a Metabolically Engineered Strain of Yarrowia lipolytica

Genome-scale metabolic models embody a significant advantage of systems biology since their applications as metabolic flux simulation models enable predictions for the production of industrially-interesting metabolites. The biotechnological production of lycopene from Yarrowia lipolytica is an emerging scope that has not been fully scrutinized, especially for what concerns cultivation conditions of newly generated engineered strains. In this study, by combining flux balance analysis (FBA) and Plackett-Burman design, we screened chemicals for lycopene production from a metabolically engineered strain of Y. lipolytica. Lycopene concentrations of 126 and 242 mg/L were achieved correspondingly from the FBA-independent and the FBA-assisted designed media in fed-batch cultivation mode. Transcriptional studies revealed upregulations of heterologous genes in media designed according to FBA, thus implying the efficiency of model predictions. Our study will potentially support upgraded lycopene and other terpenoids production from existing or prospect bioengineered strains of Y. lipolytica and/or closely related yeast species.

Upregulation of mitogen-inducible gene 6 triggers antitumor effect and attenuates progesterone resistance in endometrial carcinoma cells

Researches regarding mitogen-inducible gene 6 (Mig-6) have confirmed its role as a tumor suppressor and progesterone resistance factor in endometrium. In this study, after confirming the downregulation of Mig-6 protein in endometrial carcinoma (EC) tissues, the expression of Mig-6 was upregulated in Ishikawa cells by pCMV6-Mig-6 plasmid. We observed the increased apoptosis, decreased proliferation and invasion potential of Ishikawa cells after upregulation of Mig-6. The proapoptosis ability of P4 significantly enhanced by 39.36%, the antiproliferation ability increased by 37.90% and the anti-invasion ability increased by 48.89%, suggesting the antiprogesterone resistance potential of Mig-6 in endometrium. In addition, the results suggested that Mig-6 may induce Ishikawa cell apoptosis through the mitochondrial pathway, inhibit cell proliferation via the extracellular signal-regulated kinase pathway and the anti-invasion potential may associate with matrix metalloproteinase (MMP)-2 and MMP-9 downexpression. Therefore, upregulation of Mig-6 may add a new strategy to suppress endometrial tumorigenesis and attenuate the progesterone resistance during P4 treatment.

Anticancer Effect of Lycopene in Gastric Carcinogenesis

Gastric cancer ranks as the most common cancer and the second leading cause of cancer-related death in the world. Risk factors of gastric carcinogenesis include oxidative stress, DNA damage, Helicobacter pylori infection, bad eating habits, and smoking. Since oxidative stress is related to DNA damage, smoking, and H. pylori infection, scavenging of reactive oxygen species may be beneficial for prevention of gastric carcinogenesis. Lycopene, one of the naturally occurring carotenoids, has unique structural and chemical features that contributes to a potent antioxidant activity. It shows a potential anticancer activity and reduces gastric cancer incidence. This review will summarize anticancer effect and mechanism of lycopene on gastric carcinogenesis based on the recent experimental and clinical studies.