Sepiapterin regulates cell proliferation and migration: its association with integrin α3β1 and p53 in human lung cancer cells

Tetrahydrobiopterin from cyanide-degrading bacterium Bacillus pumilus strain SVD06 induces apoptosis in human lung adenocarcinoma cell (A549)

Tetrahydrobiopterin (BH4) is an essential biological cofactor and a derivative of pterin which is considered potent anticancer agents. In continuation of our previous study on the identification of BH4 from cyanide-degrading Bacillus pumilus, the present study focuses on evaluating the anticancer properties of BH4 on A549, a human lung adenocarcinoma. Anticancer activity analysis shows that BH4 inhibited A549 cell growth after 24 h of incubation with 0.02 mg/mL. In acridine orange/ethidium bromide staining, BH4-treated A549 cells showed apoptotic morphology. BH4 treatment caused cell cycle arrest at G0/G1 phase compared to control cells. BH4 augmented p53 expression in alveolar cancer cells by downregulating MDM2 levels. There was downregulation of casp-3 and upregulation of iNOS gene in BH4-treated A549 cells. Further, docking studies indicated that BH4 had significant interactions with the above proteins affirming the apoptosis mechanism. Thus, BH4 could be considered a potential anticancer drug.

Proteomic analysis enables distinction of early- versus advanced-stage lung adenocarcinomas

Background

A gel‐free proteomic approach was utilized to perform in‐depth tissue protein profiling of lung adenocarcinoma (ADC) and normal lung tissues from early and advanced stages of the disease. The long‐term goal of this study is to generate a large‐scale, label‐free proteomics dataset from histologically well‐classified lung ADC that can be used to increase further our understanding of disease progression and aid in identifying novel biomarkers.

Methods and results

Cases of early‐stage (I‐II) and advanced‐stage (III‐IV) lung ADCs were selected and paired with normal lung tissues from 22 patients. The histologically and clinically stratified human primary lung ADCs were analyzed by liquid chromatography‐tandem mass spectrometry. From the analysis of ADC and normal specimens, 4863 protein groups were identified. To examine the protein expression profile of ADC, a peak area‐based quantitation method was used. In early‐ and advanced‐stage ADC, 365 and 366 proteins were differentially expressed, respectively, between normal and tumor tissues (adjusted P‐value < .01, fold change ≥ 4). A total of 155 proteins were dysregulated between early‐ and advanced‐stage ADCs and 18 were suggested as early‐specific stage ADC. In silico functional analysis of the upregulated proteins in both tumor groups revealed that most of the enriched pathways are involved in mRNA metabolism. Furthermore, the most overrepresented pathways in the proteins that were unique to ADC are related to mRNA metabolic processes.

Conclusions

Further analysis of these data may provide an insight into the molecular pathways involved in disease etiology and may lead to the identification of biomarker candidates and potential targets for therapy. Our study provides potential diagnostic biomarkers for lung ADC and novel stage‐specific drug targets for rational intervention.

Analeptic agent from microbes upon cyanide degradation

Microbes being the initial form of life and ubiquitous in occurrence, they adapt to the environment quickly. The microbial metabolism undergoes alteration to ensure conducive environment either by degrading the toxic substances or producing toxins to protect themselves. The presence of cyanide waste triggers the cyanide degrading enzymes in the microbes which facilitate the microbes to utilize the cyanide for its growth. To enable the degradation of cyanide, the microbes also produce the necessary cofactors and enhancers catalyzing the degradation pathways. Pterin, a cofactor of the enzyme cyanide monooxygenase catalyzing the oxidation of cyanide, is considered to be a potentially bioactive compound. Besides that, the pterins also act as cofactor for the enzymes involved in neurotransmitter metabolism. The therapeutic values of pterin as neuromodulating agent validate the necessity to pursue the commercial production of pterin. Even though chemical synthesis is possible, the non-toxic methods of pterin production need to be given greater attention in future.

Regulatory effects of Siegesbeckia glabrescens on non-small cell lung cancer cell proliferation and invasion

Siegesbeckia glabrescens (SG) Makino (Compositae) has been used as a traditional medicine for the treatment of allergic and inflammatory diseases. In the present study, we examined the effects and molecular mechanism of the ethanol extract of SG on cell proliferation and invasion in p53 wild-type A549 and p53-deficient H1299 non-small cell lung cancer (NSCLC) cells. SG treatment markedly inhibited the proliferation and invasion in both cell lines, independently of p53 expression. The anti-proliferative effect of SG on A549 cells was mediated by the inactivation of Akt and p70(S6K) as evidenced by treatment with LY294002 and rapamycin, respectively. In addition, anti-invasive activity of SG in A549 cells was found to be associated with the inhibition of p70(S6K). In contrast, in H1299 cells the inactivation of p38(MAPK) appeared to be involved in SG-mediated inhibition of cell proliferation and invasion. Collectively, these findings suggest that SG modulates cellular fates such as proliferation and invasion by differential regulation of signaling pathways, depending on the status of p53 expression in NSCLC, and support the development of SG as a potent therapeutic agent for the treatment of NSCLC.

The in vitro antitumor activity of Siegesbeckia glabrescens against ovarian cancer through suppression of receptor tyrosine kinase expression and the signaling pathways

Siegesbeckia glabrescens (SG) Makino (Compositae) has been used as a traditional medicine for the treatment of a variety of diseases such as allergy, inflammation, acute hepatitis and hypertension. The primary aim of this study was to determine whether the ethanol extract of SG has antitumor activity against ovarian cancer and to identify molecular mechanisms and targets involved in the regulation of cell growth and progression. We demonstrate that SG treatment inhibits proliferation, adhesion, migration and invasion of SKOV-3 human ovarian cancer cells. The anti-proliferative effect of SG on SKOV-3 cells is accompanied by reduced expression of cyclin E and enhanced expression of the cyclin-dependent kinase inhibitor p27(Kip1), leading to inhibition of pRb phosphorylation. We also show that these antitumor activities are found to be mediated through suppression of FAK, ERK, Akt and p70(S6K)-dependent signaling pathways and downregulation of receptor tyrosine kinases such as EGFR, VEGFR-2 and FGFR-1 as well as the cell adhesion molecule N-cadherin. Taken together, our findings suggest further development and evaluation of SG for the treatment of ovarian cancer.