1.Inhibition of Rac Induces Hyper-Activation of c-Jun N-Terminal Kinase and Caspase-Dependent Apoptosis
Yudai Matsuoka ; Hirokazu Nakahara ; Shinichi Nozaki ; Tomohiro Otani ; Mikihiko Kogo
Oral Science International 2008;5(1):52-60
Apoptosis is one mechanism by which cancer cells can be eliminated. Therefore, understanding the signaling pathways that transduce apoptotic signals in cancer cells is an indispensable component of cancer research. Rac, a member of the Rho family of proteins, has been implicated in the regulation of cell survival and apoptosis. However, the mechanisms underlying this process remain to be elucidated. To understand the role of Rac in oral squamous cancer, we inhibited its activity by a Rac-specific small molecule inhibitor, NSC23766, or transfection of dominant negative Rac (Rac-DN), and discovered that inhibition of Rac activity elicits apoptosis in highly malignant oral squamous carcinoma (OSC-19) cells. Upon suppression of Rac, we observed up-regulation of c-Jun N-terminal kinase (JNK), leading to caspase-dependent apoptosis. Furthermore, stimulation of protein phosphatase (PP5) rescued apoptosis caused by Rac inhibition by dephosphorylating JNK. Taken together, inhibition of Rac activity leads to the suppression of PP5 activity, which results in extensive activation of JNK and caspase-dependent apoptosis. In conclusion, Rac inhibition may represent a novel therapeutic approach for oral squamous carcinoma.
2.The Effect of Psychological Status and Family Function in Breast Cancer Patients on Their Children’s Quality of Life (Effect of Family Function in Breast Cancer Patients on Children)
Yuying TANG ; Haruka ONO ; Yuko OGAWA ; Miwa OZAWA ; Tomohiro TAMAKI ; Hiroyuki OTANI ; Sachiko KIYOTO ; Shin-ichi SUZUKI
Palliative Care Research 2021;16(2):169-177
Objective: The influence of depression, anxiety, and family function in breast cancer patients on the quality of life of their children was investigated from the perspective of the participants’ demographic characteristics after controlling for their attributes. Methods: The demographic characteristics and confounding factors were divided into two subgroups, and two-factor analysis of variance was conducted with depression, anxiety, and family function as the independent variables, and the children’s quality of life scores as the dependent variable. Results: The quality of life of children in each characteristic demographic-subgroup was significantly lower when their mother had high depressed. Moreover, the quality of life in children of the subgroup with mothers receiving chemotherapy varied according to the quality of family function regardless of having siblings. Conclusion: It is necessary to focus on the conditions of children in addition to the psychological status of breast cancer patients. This investigation suggested that understanding mothers’ psychological status helps to identify children’s psychosocial problems. Moreover, it is suggested that the demographic characteristics of families with breast cancer patients should be considered when approaching mothers’ psychological status and family function.
3.Validation of a Trainer for Improving Knot-Tying Skills Using Gummy Candies
Minoru AOYAMA ; Yoko NAKAZATO ; Tomohiro SANO ; Ruriko HIKI ; Natsumi UESHIMA ; Ryo KANEDA ; Momoka OTANI ; Ryota TANAKA
Medical Education 2024;55(5):403-407
Introduction: We evaluated a trainer for improving knot-tying skills using gummy candies (KTG; knot-tying trainer using gummy). To reveal its efficacy, the KTG was compared with a standard knot-tying board by evaluating construct and concurrent validities. Method: The completion times for knot-tying with the both the trainers were recorded for 18 novices and 18 experts in our university hospital. The evaluation formula was published previously and comprised four items (accuracy, gap, slippage, and breakage) to calculate the total score. Results: With the standard knot-tying board, the average score was 27.1±22.6 points in the novice group and 37.3±18.7 points in the expert group. There was no statistically significant difference between the groups. With the KTG, the average score was 12.3±20.6 points in the novice group and 36.7±18.3 points in the expert group, with a statistically significant difference (p<0.001). Discussion: Using the KTG for knot-tying training, it may be possible to acquire knot-tying skills with proficiency-based training, which could improve knot-tying technique.