Ovarian cancer is one of the most aggressive female reproductive tract tumors. Paclitaxel (PTX) is widely used for the treatment of ovarian cancer. However, ovarian cancers often acquire chemotherapeutic resistance to this agent. We investigated the mechanism of chemoresistance by analysis of microRNAs using the ovarian cancer cell line KFr13 and its PTX-resistant derivative (KFr13Tx). We found that miR-31 was downregulated in KFr13Tx cells, and that re-introduction of miR31 re-sensitized them to PTX both in vitro and in vivo. miR-31 was found to bind to the 3′-UTR of mRNA of MET, and the decrease in MET correlated to higher sensitivity to PTX. Furthermore, co-treatment of KFr13Tx cells with MET inhibitors sensitized the tumor cells to PTX both in vitro and in vivo. In addition, lower levels of miR31 and higher expression of MET in human ovarian cancer specimens were significantly correlated with PTX chemoresistance and poor prognosis. This study demonstrated miR31-dependent regulation of MET for chemoresistance of ovarian cancer, raising the possibility that combination therapy with a MET inhibitor and PTX will increase PTX efficacy.

Few surface modification processes appear to coat a 1 mm thick compact layer on a substrate successfully, although several technologies have been proposed and applied. The present paper concerns a fundamental approach to establishing a friction surfacing technique that produces a 1mm thick hard coat. Experiments were carried out to clarify the effect of process parameters on the quality of coatings. Martensitic stainless steel with 1C-17 Cr was the coating material and low carbon structural steel the substrate, using a conventional friction welding machine equipped with a sliding stage. A 20 mm wide and 1 mm thick stable hardened layer was produced using a 20 mm dia. Rod of coating material. The dimensions of the layer depend on the rotational speed of the consumable rod, as lower rotational speeds produce thicker, wider coating layers. Calorimetric measurements revealed that the total heat input rate was not influenced by the frictional speed, however the ratio of thermal distributions on to the substrate and rod was significantly affected by rotational speed. Additional experiments were carried out to clarify the effect of edge preparation, rotational direction, and overlapping distance on defect formation in multilayer depositions by friction coating for wide area coating on steel plates. Results were optimised by grinding the edges of previous layers to prevent defects such as incomplete bonding.

In this work, a feasibility study has been conducted on the formation of NiTi intermetallic compound coating by plasma transferred arc (PTA) surfacing process. The filler materials used were alloyed powder of NiTi and physically mixed powder of nickel and titanium. Wear characteristics of the coatings were evaluated by a modified Okoshi-type wear tester.It was found that it is possible to produce intermetallic compound coatings from the mixed powder as well as alloyed powder by PTA surfacing process. The wear resistance of the coatings formed from alloyed powder (the NiTi coating) is superior to the resistance of Stellite ♯6 coatings. The coatings formed from mixed powder (the Ni＋Ti coating) have wear resistance similar to that of Stellite ♯6 coatings. X-ray diffraction result indicates that the NiTi coatings mainly consist of NiTi phase, whereas the Ni ＋Ti coatings principally consist of NiTi and FeTi phases. Hardness values of both NiTi and Ni＋Ti coatings reached to 800HV or more, and then minute cracks were observed in both coatings.

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