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@#Objective: To study the effects of vitamin C (VC) on reversing cisplatin (DDP) resistance in oral squamous cell carcinoma (OSCC) and the mechanism. Methods: Human OSCC CAL27 cells were cultured in vitro and DDP-resistant CAL27 cell line (CAL27/ DDP) was screened by increasing concentration gradient method. Plate clone formation assay, CCK-8, Wound healing assay, Annexin V-FITC/PI staining flow cytometry were used to determine the effects of DDP alone or in combination with VC on colony formation, proliferation, migration and apoptosis of CAL27/DDP cells. Western blotting was used to detect the expression level of P-gp protein in CAL27 cells, CAL27/DDP cells and VC treated CAL27/DDP cells. Results: The inhibition concentration (IC50) of DDP increased significantly in CAL27/DDP cells as compared with that in CAL27 cells (P<0.05), indicating CAL27/DDP was DDP-resistant.After the combination with VC, the IC50 of DDP on CAL27/DDP cells was significantly reduced compared with that of DDP alone (P<0.05). DDP combined with VC significantly inhibited the migration of CAL27/DDP cells (P<0.01), and promoted the apoptosis rate (P<0.01). The expression level of P-gp protein in CAL27/DDP cells was increased compared with that in CAL27 cells (P<0.05), but decreased after VC intervention (P<0.05). Conclusion: VC can reverse DDP-resistance in OSCC cells by inhibiting P-gp protein expression.
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@#口腔鳞状细胞癌是头颈部常见的恶性肿瘤，化疗是其常规治疗手段之一，铂类化疗药物作为一线化疗药物应用于口 腔鳞状细胞癌的治疗中。然而化疗耐药极大地限制了铂类化疗药物的临床应用，因此阐明口腔鳞状细胞癌铂类化疗耐药的分子 机制具有十分重要的临床意义。本文从药物转运蛋白、DNA损伤修复、细胞凋亡、自噬、上皮间质转化和miRNA等方面综述了口 腔鳞状细胞癌铂类化疗耐药的分子机制，以期为逆转铂类耐药及相关肿瘤的生物治疗靶点的开发提供新的思路。
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<p><b>OBJECTIVE</b>To explore the effects of resuscitation with different kinds of colloids on oxygen metabolism of swine during shock stage of burn injury.</p><p><b>METHODS</b>Eighteen Guangxi Bama miniature swine were inflicted with 40% TBSA full-thickness burn on the back. And then they were divided into succinylated gelatin group (S) , hydroxyethyl starch group (H), and allogeneic plasma group (A) according to the random number table, with 6 swine in each group. The fluid resuscitation was begun at post injury hour (PIH) 2. The colloids used in groups S, H, and A were respectively succinylated gelatin, 60 g/L hydroxyethyl starch 130/0.4, and allogeneic plasma. The blood pressure, urine volume, heart rate, and central venous pressure (CVP) were recorded before injury and at the first and second PIH 24. The volume of resuscitation fluid was recorded at the first and second PIH 24. The changes in oxygen delivery., oxygen consumption, oxygen extraction ratio and D-lactate were determined and calculated before injury and at PIH 4, 8, 24, and 48. Data were processed with analysis of variance of repeated measurement, one-way analysis of variance and LSD test.</p><p><b>RESULTS</b>There were no statistically significant differences among the three groups in blood pressure, urine volume, heart rate, and CVP at each time point (with P values above 0. 05). There were no statistically significant differences in resuscitation fluid volume among the three groups at the first and second PIH 24 (with F values respectively 0. 239 and 2. 023, P values respectively 0. 790 and 0. 167). The oxygen consumption of swine in group S was (201 ± 38) L · min(-1) · m(-2) at PIH 48, which was significantly higher than that in group A [(150 ± 37) L · min(-1) · m(-2), P < 0.05], and the oxygen consumption was similar among the three groups at the rest time points (with P values above 0.05). The oxygen delivery of swine in group S was (484 ± 63) L · min(-1) · m(-2) at PIH 8, and it was significantly lower than that in group A [(652 ± 65) L(-1) min(-1) · m(-2), P < 0.01]. The oxygen delivery of swine in group S reached (903 ± 132) and (1,028 ± 98) L · min(-1) · m(-2) at PIH 24 and 48, respectively, and they were significantly higher than those in group A [(686 ± 72) and (720 ± 75) L · min(-1) · M(-2), with P values below 0.01]. Oxygen delivery in group H was similar to that of group A at each time point (with P values above 0.05). The oxygen extraction ratio in group S or group H was close to that of group A at each time point (with P values above 0.05). The D-lactate level in group S was (69 ± 9) mmol/L, and it was significantly higher than that in group A [(52 ± 4) mmol/L, P < 0.01] at PIH 48. The D-lactate level was similar among the three groups at the rest time points (with P values above 0.05).</p><p><b>CONCLUSIONS</b>According to the changes in oxygen metabolism of swine during shock stage of burn injury resuscitated with different kinds of colloids, it is found that allogeneic plasma is better than artificial colloid, and 60 g/L hydroxyethyl starch 130/0.4 is superior to succinylated gelatin.</p>