How organs maintain and restore functional integrity during ordinary tissue turnover or following injury represents a central biological problem. The maintenance of taste sensory organs in the tongue was shown 140 years ago to depend on innervation from distant ganglion neurons, but the underlying mechanism has remained unknown. Here, we show that Sonic hedgehog (Shh), which encodes a secreted protein signal, is expressed in these sensory neurons, and that experimental ablation of neuronal Shh expression causes loss of taste receptor cells (TRCs). TRCs are also lost upon pharmacologic blockade of Hedgehog pathway response, accounting for the loss of taste sensation experienced by cancer patients undergoing Hedgehog inhibitor treatment. We find that TRC regeneration following such pharmacologic ablation requires neuronal expression of Shh and can be substantially enhanced by pharmacologic activation of Hedgehog response. Such pharmacologic enhancement of Hedgehog response, however, results in additional TRC formation at many ectopic sites, unlike the site-restricted regeneration specified by the projection pattern of Shh-expressing neurons. Stable regeneration of TRCs thus requires neuronal Shh, illustrating the principle that neuronal delivery of cues such as the Shh signal can pattern distant cellular responses to assure functional integrity during tissue maintenance and regeneration.
Oxymatrine (OMT), one of the main active components of extracts from the dry roots of Sophora flavescens, has been reported to possess many pharmacological properties including cancer-preventive and anti-cancer effects. The aim of the present study is to explore the efficiency of combination therapy with OMT and oxaliplatin (OXA) and identify the in vitro and in vivo cytotoxicity on colon cancer lines (HT29 and SW480) and mice model. Cells were treated with OMT and/or OXA and subjected to cell viability, colony formation, apoptosis, cell cycle, western blotting, xenograft tumorigenicity assay and immunohistochemistry. The results demonstrated that OMT and OXA inhibited the proliferation of colon cancer cells, and combination therapy of OMT and OXA resulted in a combination index < 1, indicating a synergistic effect. Co-treatment with OMT and OXA caused G0/G1 phase arrest by upregulating P21, P27 and downregulating cyclin D, and induced apoptosis through decreasing the expression of p-PI3K, p-AKT, p-mTOR, p-p70S6K. In addition, pretreatment with a specific PI3K/AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of OXA + OMT, demonstrating the important role of PI3K/AKT in this process. Moreover, in nude mice model, co-treatment displayed more efficient inhibition of tumor weight and volume on SW480 xenograft mouse model than single-agent treatment with OXA or OMT. Immunohistochemistry analysis suggests the combinations greatly suppressed tumor proliferation, which consistent with our in vitro results. In conclusion, our findings highlight that the combination therapy with OMT and OXA exerted synergistic antitumor effects in colon cancer cells through PI3K/AKT/mTOR pathway and combination treatment with OMT and OXA would be a promising therapeutic strategy for colon carcinoma treatment.
Predictive models are one of the most important techniques that are widely applied in many areas of software engineering. There have been a large number of primary studies that apply predictive models and that present well-performed studies in various research domains, including software requirements, software design and development, testing and debugging and software maintenance. This paper is a first attempt to systematically organize knowledge in this area by surveying a body of 421 papers on predictive models published between 2009 and 2020. We describe the key models and approaches used, classify the different models, summarize the range of key application areas, and analyze research results. Based on our findings, we also propose a set of current challenges that still need to be addressed in future work and provide a proposed research road map for these opportunities.
Lupeol, a dietary triterpene, present in many fruits and medicinal plants, has been reported to possess many pharmacological properties including anti-cancer activities both in vitro and in vivo. However, the precise mechanism involved remains largely unknown. The present study is conducted to investigate the anti-cancer activity and the underlying mechanisms of lupeol on human pancreatic cancer proliferating cell nuclear antigen 1 (PCNA-1) cells in vitro and in vivo. Lupeol significantly inhibited the proliferation of the cells in dose- and time-dependent manners and induced apoptosis as well as cell cycle arrest in G0/G1 phase by upregulating P21 and P27 and downregulating cyclin D1. The expression of apoptosis-related proteins in cells was evaluated by western blot analysis, and we found that lupeol induced cell apoptosis by decreasing the levels of p-AKT and p-ERK. In addition, pretreatment with a specific PI3K/AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of lupeol in PCNA-1 cells, demonstrating the important role of AKT in this process. More importantly, our in vivo studies showed that administration of lupeol decreased tumor growth in a dose-dependent manner. Immunohistochemistry analysis demonstrated the downregulation of p-AKT and p-ERK in tumor tissues following lupeol treatment, consistent with the in vitro results. Therefore, these findings indicate that lupeol can inhibit cell proliferation and induce apoptosis as well as cell cycle arrest of PCNA-1 cells and might offer a therapeutic potential advantage for human pancreatic cancer chemoprevention or chemotherapy.
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