ABSTRACT
Oral squamous cell carcinoma (OSCC) is the fifth common cause of cancer mortality in Taiwan with high incidence and recurrence and needs new therapeutic strategies. In this study, ursolic acid (UA), a triterpenoid, was examined the antitumor potency in OSCC cells. Our results showed that UA inhibited the proliferation of OSCC cells in a dose- and time-dependent manner in both Ca922 and SCC2095 oral cancer cells. UA induced caspase-dependent apoptosis accompanied with the modulation of various biological biomarkers including downregulating Akt/mTOR/NF-κB signaling, ERK, and p38. In addition, UA inhibited angiogenesis as evidenced by abrogation of migration/invasion and blocking MMP-2 secretion in Ca922 cells. Interestingly, UA induced autophagy in OSCC cells, as manifested by LC3B-II conversion and increased p62 expression and accumulation of autophagosomes. Inhibition by autophagy inhibitor enhanced UA-mediated apoptosis in Ca922 cells. The experiment provides a rationale for using triterpenoid in the treatment of OSCC.
Subject(s)
Angiogenesis Inhibitors/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , Carcinoma, Squamous Cell/pathology , Mouth Neoplasms/pathology , Triterpenes/pharmacology , Carcinoma, Squamous Cell/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Down-Regulation , Humans , Mouth Neoplasms/metabolism , NF-kappa B/metabolism , Signal Transduction , Ursolic AcidABSTRACT
BACKGROUND: Social cognitive career theory (SCCT) can explain the mechanism underlying the formulation of nurse turnover intention. However, little is known about the role of professional commitment in such a mechanism. AIMS: The aim of this study was to explore how elements of SCCT have an impact on the three aspects of professional commitment and thus nurses' intention to leave the profession. DESIGN: This study used surveys to collect two-wave data. METHODS: The participants were sampled in all available units of a major medical centre in 2017. By using proportionate random sampling methods, we successfully followed up a representative sample of 524 full-time nurses. Most participants (98.1%) were female. Items came from Cunningham et al.'s Self-Efficacy Scale, Outcome Expectations Scale, Human Capital Scale and Vocational Interest Scale; Meyer et al.'s Professional Commitment Scale; and Teng et al.'s Turnover Intention Scale. Structural equation modelling was used to test the hypotheses. RESULTS: Self-efficacy was positively related to outcome expectation. Outcome expectation was positively related to career interest. Career interest was positively related to affective professional commitment. Human capital was positively related to normative professional commitment. Affective professional commitment was positively related to intention to improve professional capabilities, which was further negatively related to intention to leave the profession. CONCLUSION: Aspects of professional commitment are important process variables in the impact of self-efficacy and outcome expectation on nurses' turnover intention.