Hedgehog signaling in gastrointestinal carcinogenesis and the gastrointestinal tumor microenvironment

The Hedgehog (HH) signaling pathway plays important roles in gastrointestinal carcinogenesis and the gastrointestinal tumor microenvironment (TME). Aberrant HH signaling activation may accelerate the growth of gastrointestinal tumors and lead to tumor immune tolerance and drug resistance. The interaction between HH signaling and the TME is intimately involved in these processes, for example, tumor growth, tumor immune tolerance, inflammation, and drug resistance. Evidence indicates that inflammatory factors in the TME, such as interleukin 6 (IL-6) and interferon-γ (IFN-γ), macrophages, and T cell-dependent immune responses, play a vital role in tumor growth by affecting the HH signaling pathway. Moreover, inhibition of proliferating cancer-associated fibroblasts (CAFs) and inflammatory factors can normalize the TME by suppressing HH signaling. Furthermore, aberrant HH signaling activation is favorable to both the proliferation of cancer stem cells (CSCs) and the drug resistance of gastrointestinal tumors. This review discusses the current understanding of the role and mechanism of aberrant HH signaling activation in gastrointestinal carcinogenesis, the gastrointestinal TME, tumor immune tolerance and drug resistance and highlights the underlying therapeutic opportunities.

1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) increases Carmofur stability and in vitro antiproliferative effect

Addition of DMPC considerably inhibits the degradation of Carmofur in neutral phosphate buffer solutions and this drug becomes less influenced by pH. Carmofur stabilization at neutral pH caused by DMPC addition for in vitro studies was characterized and monitored by ¹H NMR. Antiproliferative activity studies on various tumor cell lines showed considerable increase of Carmofur ability to prevent tumor cell growth, when it is added as a mixture with DMPC. This technique opens a way for Carmofur drug delivery in neutral and basic media.

Identification of functional tissue-resident cardiac stem/progenitor cells in adult mouse

In most somatic tissues, ASCs (adult stem cells) are crucial for the maintenance of tissue homoeostasis under normal physiological state and recovery from injury. LRC (label retaining cell) assay is a well-known method of identifying possible somatic stem/progenitor cells and their location both in situ and in vivo. BrdU (bromodeoxyuridine) was used here to tag the possible CSCs (cardiac stem cells)/CPCs (cardiac progenitor cells) in newborn pups, followed by a trace period of up to 24 months. In addition, we have used our newly developed 'KAL' method to rapidly Kill proliferating cells in adult heart tissues, then, Activate and Label the surviving CSCs/CPCs. LRCs that definitively exist in the heart tissues of adult mice, and some LRCs express the stem cell marker, Sca-1 or c-Kit, and are located primarily in the myocardium and vascular endothelial regions. Moreover, the number of LRCs remains nearly constant during the lifespan of the mouse. After injury induced by 5-fluorouracil, the proliferating cells were almost completely cleared on day 3, and the activated CSCs/CPCs retained their BrdU label after regeneration was complete. A small percentage of the CSCs/CPCs express Sca-1 or c-Kit. Furthermore, the LRC method together with KAL may be used to identify and locate possible CSCs/CPCs, which has potential clinical application.