TGF-ß Signaling and Resistance to Cancer Therapy.

The transforming growth factor ß (TGF-ß) pathway, which is well studied for its ability to inhibit cell proliferation in early stages of tumorigenesis while promoting epithelial-mesenchymal transition and invasion in advanced cancer, is considered to act as a double-edged sword in cancer. Multiple inhibitors have been developed to target TGF-ß signaling, but results from clinical trials were inconsistent, suggesting that the functions of TGF-ß in human cancers are not yet fully explored. Multiple drug resistance is a major challenge in cancer therapy; emerging evidence indicates that TGF-ß signaling may be a key factor in cancer resistance to chemotherapy, targeted therapy and immunotherapy. Finally, combining anti-TGF-ß therapy with other cancer therapy is an attractive venue to be explored for the treatment of therapy-resistant cancer.

Heat exposure affected the reproductive performance of pregnant mice: Enhancement of autophagy and alteration of subcellular structure in the corpus luteum.

To investigate whether autophagy and subcellular changes are involved in the corpus luteum after heat exposure, a total of 30 early pregnant mice were divided equally into heat stress (HS) and non-HS (NHS) groups (n = 15). Mice in the HS group were exposed to 40.5 ±â€¯0.2 ℃ for 7 consecutive days. Ovaries were collected for immunohistochemistry (IHC), western blot (WB) analysis and transmission electron microscopy (TEM). Serum was collected to determine progesterone by RIA and uteri were collected to count the implantation sites. Results showed that heat exposure increased rectal temperature, decreased body weight and number of implantation sites. WB analysis revealed that ovarian expression of LC3B and Atg7 was up-regulated, while p62 was down-regulated in the HS group. IHC results demonstrated that ovarian staining intensity of LC3B was more intense in the HS group than that of the NHS group. LC3B was mainly localized in the granulosa cells, oocytes and luteal steroidogenic cells of the HS group. TEM results revealed double-layered separated membranes indicative of autophagosomes in the luteal steroidogenic cells of the HS group. Moreover, TEM showed that the mitochondrial cristae became dearth, structure-less, swollen after HS. Additionally, the nucleus expanded and accumulation of lipid droplets increased after HS. Results also showed that heat exposure decreased serum progesterone level and ovarian P450scc expression. These results indicate that HS enhanced autophagy and altered the subcellular structure of luteal steroidogenic cells, which may contribute to interfering with the maintenance of luteal function in early pregnant mice.