Oral squamous cell carcinoma (OSCC) cells are usually resistant to doxorubicin, resulting in limited application of doxorubicin in OSCC treatment. MicroRNA (miR)-221 has been reported to be involved in the development of OSCC; however, it remains unclear if and how miR-221 is implicated in modulating the sensitivity of OSCC cells to doxorubicin. In the present study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to assess miR-221 expression in OSCC cells in response to doxorubicin treatment. In addition, the SCC4 and SCC9 OSCC cell lines were transfected with anti-miR-221 oligonucleotides and cell viability and apoptosis following doxorubicin treatment were evaluated using an MTT assay and Annexin V-fluorescein isothiocyanate/Hoechst double staining, respectively. The mRNA and protein expression levels of tissue inhibitor of metalloproteinase-3 (TIMP3) in anti-miR-221-transfected cells were assessed using RT-qPCR and western blot analysis, respectively. Furthermore, a luciferase reporter assay was performed to investigate whether TIMP3 may be a direct target gene of miR-221. To explore the roles of TIMP3 in miR-221-mediated cell responses, TIMP3 expression was silenced following transfection with TIMP3-targeting small interfering (si)RNA in cells overexpressing miR-221, and cell viability and apoptosis in response to doxorubicin treatment were measured. The results of the present study demonstrated that miR-221 expression was upregulated in SCC4 and SCC9 cells following treatment with doxorubicin. However, inhibiting the doxorubicin-induced upregulation of miR-221 through transfection with anti-miR-221 oligonucleotides led to an increase in the sensitivity of OSCC cells to doxorubicin. In addition, the results indicated that TIMP3 was a direct target of miR-221 in OSCC cells, as determined by a 3′-untranslated region luciferase reporter assay. Co-transfection of cells with anti-miR-221 oligonucleotides and TIMP3-specific small interfering RNA resulted in reduced sensitivity to doxorubicin compared with the cells transfected with the miR-221 inhibitor alone. In conclusion, these results indicated that OSCC cells are resistant to doxorubicin through upregulation of miR-221, which in turn downregulates TIMP3. Therefore, silencing miR-221 or upregulating TIMP3 may be considered promising therapeutic approaches to enhance the sensitivity of OSCC to doxorubicin.

Abstract. CCN2 and CCN3 belong to the CCN family of proteins, which show a high level of structural similarity. Previous studies have shown that CCN2 mediates the ability of transforming growth factor (TGF)-β to stimulate collagen synthesis, leading to keloid formation. CCN2 and CCN3 are opposing factors in regulating the promoter activity and secretion of this extracellular matrix (ECM) protein. Thus, we hypothesize that CCN3 possesses an anti-scarring effect. However, the exact mechanism of CCN3 in this anti-scarring effect remains unclear. The aim of this study was to investigate the mechanism of CCN3 in reducing scar formation. Palatal fibroblasts were obtained from the explants of the oral palatal mucosa of 8-week-old male Sprague-Dawley rats. CCN3 overexpression vector was constructed and then transfected into cells. The inhibitory effects of CCN3 on cell growth were detected via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured using an Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) apoptosis detection kit and flow cytometry. The expression levels of collagen I, collagen III and α-smooth muscle actin (α-SMA) were determined by western blot analysis and RT-PCR. Following treatment with TGF-β1, we detected the expression of CCN3 and Smad1 in the fibroblasts. CCN3 significantly inhibited the growth and induction of apoptosis of fibroblasts. The expression of collagen I, collagen III and α-SMA was lower in the CCN3-transfected group as compared to the control and vector groups. TGF-β1 stimulation efficiently suppressed the expression of CCN3 at the mRNA and protein levels, and CCN3 was required for TGF-β1-induced Smad1 phosphorylation. Results of this study demonstrated that CCN3 is involved in the proliferation and apoptosis of fibroblasts and the synthesis of ECM proteins. Therefore, CCN3 may play an important role in the development of scar tissue, and may represent a novel therapeutic target for reducing scar formation.

Background: Determining the mental health status of parents who chronically care for a child with speech impairment is important for developing appropriate interventions to improve both parents' and children's health and achieve a win-win situation. Unfortunately, no study in China has explored this issue. This study investigated the differences in four aspects of mental health between maternal and paternal caregivers for the Mandarin-speaking children with speech impairment and determine whether depressive symptoms mediate the relationships between anxiety symptoms and suicidal ideation, hopelessness and suicidal ideation.Methods: This cross-sectional questionnaire survey was conducted in February 2020 by sending a link to the predesigned electronic questionnaire in WeChat. Standardized assessment tools were employed. Hierarchical multiple logistic regression was conducted to examine the associations between various factors and suicidal ideation, and two separate structural equation models were performed to evaluate the mediating effects of depressive symptoms in the relationship between anxiety symptoms and suicidal ideation as well as between hopelessness and suicidal ideation.Results: This study included 446 parental caregivers of Mandarin-speaking children with speech impairment. Paternal caregivers had greater score than maternal caregivers on loss of motivation (one of the subdomains of hopelessness). Somatic complications of the child (OR = 2.73, 95% CI: 1.09–6.67) and depressive symptoms (OR = 3.38, 95% CI: 1.83–6.30) were positively associated with caregivers' suicidal ideation. Having speech therapy of child (OR = 0.54, 95% CI: 0.29–0.98) was negatively correlated with caregivers' suicidal ideation. There was direct effect of depressive symptoms on suicidal ideation. Depressive symptoms play mediating roles on the relationships between anxiety symptoms (β = 0.171, p < 0.001) as well as between hopelessness and suicidal ideation (β = 0.187, p < 0.001).Conclusions: Paternal and maternal caregivers of Mandarin-speaking children with speech impairment suffered from mental health problems. Preventive strategies and interventions to ameliorate parental psychological well-being, and health care policies to increase the accessibility to speech therapy care of children with speech impairment are imperative.