OBJECTIVE Endoscopic cauterization is an effective method for treating pyriform sinus fistula (PSF). However, these approaches sometimes result in a higher failure rate. We present an effective technique utilizing suture combined with chemocauterization as first-line treatment in patients with PSF and evaluate the safety and efficacy of its use in 126 patients. STUDY DESIGN Retrospective study. SETTING Tertiary referral center. METHODS Retrospective case review of patients treated between March 2012 and June 2021 at our institution with descriptive statistical analysis. RESULTS A total of 126 patients with PSF were included in this study with a mean age of 14.7 years. There was no sex predilection. The majority of patients presented with a left-sided neck lesion (89.7%). Ten patients presented following prior attempts at the surgery of the PSF at another institution; 8 via open surgery and 2 following endoscopic CO2 laser cauterization; other patients only had a history of repeat incision and drainage or antibiotic treatment. The success rate of obliteration of the internal opening was 96.83% after a single treatment without complications. Following reoperation, a successful outcome was achieved in the remaining 4 patients. Length of stay ranged from 10 to 14 days. No recurrences occurred within 12 to 120 months followed-up. CONCLUSION Endoscopic suture combined with chemocauterization is a safe and effective treatment of PSF. Surgery can be performed during the acute cervical inflammatory period without increased risk of complication or recurrence, however, patients found to have acute changes affecting the pyriform sinus should be treated with a staged surgery strategy.

目的 分析舌甲状舌管囊肿(lingual thyroglossal duct cysts,LTGDC)的临床特征,探讨行扩大Sistrunk手术切除复发LTGDC的临床疗效.方法 回顾性分析2007年6月～2018年1月在我科收治的15例LTDGC临床资料,男11例,女4例,年龄18～55岁.12例患者既往有1～3次不等的手术切除史,手术后2周～10个月间复发.手术均经颈前入路进入咽腔,采用扩大的Sistrunk术式切除囊肿.结果 术后咽瘘1例,经换药保守治疗愈合.1例行气管切开,出院前拔管.患者术后均无吞咽不适及言语异常.所有患者均随访2年以上无复发.结论 LTDGC临床误诊率高,经内镜下切除容易复发.采用颈前入路扩大Sistrunk术式切除LTGDC为首选术式,临床效果可靠.

Objective: Hypopharyngeal squamous cell carcinoma (HSCC) remains one of the most lethal malignancies in head and neck.Notch1 has been validated to play prominent roles in the occurrence and development of various types of cancer.The aim of this study was to explore the function and underlying mechanism of Notch1 in HSCC.Patients and methods: Seventy-one cancer tissue samples and adjacent noncancerous formalin-fixed paraffin embedded tissue specimens were analyzed by immunohistochemistry.As Notch1 is overexpressed in HSCC, we further questioned whether there was a relationship between Notch1 and the clinicopathological characteristics.After confirming the successful knockdown of Notch1 by siRNA, the migration and invasion after gene knockdown were investigated by Transwell chambers.We then tried to identify YBX1 and EGFR expression using real-time PCR (RT-PCR) and Western blot analyses.To further determine whether the downexpression of EGFR was caused by YBX1 and the overexpression of YBX1 was caused by gene amplification, the expression of EGFR was detected by RT-PCR and Western blot assays.Results: We found that the expression of Notch1 and EGFR in HSCC tissues was upregulated compared with those in the adjacent noncancerous tissues.Further clinicopathological characteristics analysis revealed that the expression of Notch1 was positively correlated with distant metastasis (P=0.003) and tumor differentiation (P=0.031).The high expression of Notch1 is an independent prognostic factor for a poor overall survival in patients with HSCC (P=0.015,χ 2 =10.403).Knocking down of Notch1 significantly inhibits the migration and invasion of FaDu cells in vitro.Mechanistic investigation reveals that Notch1 knockdown is found suppressing the expression of EGFR at transcriptional level.Interestingly, we further found that Notch1 knockdown also decreased the expression of YBX1, which is a transcription factor of EGFR.Moreover, the upregulation of YBX1 reverses the suppression of Notch1 on EGFR.Furthermore, forced overexpression of YBX1 induced the invasion of FaDu cells.Conclusion: Taken together, we found a positively cross-linked role of Notch1 signaling in the outcome of HSCC, providing a novel valuable prognostic marker and potential therapeutic target for the treatment of HSCC patients.Notch1 is a core signaling molecule for regulating migration and invasion via interplaying with EGFR in HSCC cells.

Objective To evaluate the effectiveness of endoscopic cauterization and mucosal suturing surgical management in the treatment of pyriform sinus fistula.Methods From March 2012 to December 2014, 16 patients were performed endoscopic closure of pyriform sinus fistula by mucosal suturing.All patients were treated with endoscopic cauterization and mucosal suturing.Patients presenting with acute neck abscess were processed simultaneously with surgical management of incision and drainage.There were 9 males and 7 females.The ages ranged from 6 to 54 years old.The lesions were predominantly left sided (13/16), and generally presented as acute suppurative thyroiditis (9/16) or recurrent neck abscess (5/16), two patients presented with pharyngocutaneous fistula following ipsilateral thyroidectomy.Among them, 11 patients showed acute neck infections or pharyngocutaneous fistula at the time of hospitalization.Results Two weeks post-operation, telescopic hypopharyngoscopy was employed to confirm the closure of the internal opening in all patients, and they all presented with the formation of scar tissue at piriform fossa.Following external incision and drainage, all cases presenting with acute neck abscess recovered within two weeks.Except one case presented with slight thyroiditis and rapidly recovered after antibiotic treatment, there were no serious complications and no recurrence within the follow-up period ranging from 13 to 41 months.Conclusions Endoscopic mucosal suturing closure of the internal opening is a safe and effective treatment for pyriform sinus fistula patients.Patients presenting with acute neck abscess should be processed simultaneously with incision and drainage.

Multidrug resistance (MDR) is one of the most important obstacles affecting the efficacy of chemotherapy treatments for numerous types of cancer. In the present study, we have demonstrated the possible function of Twist1 in the chemosensitivity of head and neck squamous cell carcinoma (HNSCC) and have identified that its mechanism maybe associated with MDR1/P-gp regulation. To investigate this, the hypopharyngeal cancer cell line, FaDu, and its MDR cell line induced by taxol, FaDu/T, were employed. Stable transfectants targeted to Twist1 overexpression and Twist1 silencing based on FaDu were also conducted. Morphological observation, flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR), western blotting and laser scanning confocal microscope detection were utilized to detect the associations between Twist1 and the chemosensitivity of FaDu cells. Our results demonstrated that Twist1 and MDR1/P-gp were upregulated in FaDu/T cells in a MDR dose-dependent manner. The anti-apoptotic capabilities of FaDu/T cells were enhanced during MDR progression, with apoptosis-related proteins (Bcl-2, Bax, activated caspase-3 and caspase-9) changing to resist apoptosis. Twist1 overexpression decreased the sensitivity of cells to taxol as revealed by a significant increase in MDR1/P-gp and IC50 (P<0.05). This overexpression also enhanced the resistance to apoptosis, with apoptotic proteins changing to resist cell death, and inhibited Ca2+ release induced by taxol (P<0.05). Detections in Twist1 silencing cells also confirmed this result. This study provided evidence that alterations of Twist1 expression modulates the chemosensitivity of FaDu cells to taxol. Therefore, Twist1 knockdown may be a promising treatment regimen for advanced hypopharyngeal carcinoma patients with MDR.

In order to reverse the malignant characteristics of hypopharyngeal cancer, the proteasome inhibitor MG132 was introduced into FaDu/T cells and the mechanisms underlying its effects were investigated. The multi-drug resistance (MDR) sensitivities of FaDu/T and FaDu/T-MG132 cancer cells to several chemotherapeutics were investigated by a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured by staining cells with Annexin V and propidium iodide (PI) double staining. Reverse transcription-polymerase chain reaction and western blot analysis were conducted to detect mRNA and corresponding protein levels of the MDR- and apoptosis-related genes P-glycoprotein (P-gp), caspase-3, Bcl-2 and Bax. The nuclear protein of nuclear factor κ-light-chain-enhancer of activated B cells. (NF-κB) and p53 were also investigated via western blot analysis. Compared with FaDu/T cells, the drug resistance of FaDu/T + MG132 cells to cisplatin (DDP), 5-fluorouracil (5-FU), doxorubicin (Dox) and vincristine (VCR) decreased. With increased expression of caspase-3 and Bax and decreased expression of Bcl-2, the anti-apoptotic ability markedly decreased in FaDu/T + MG132 cells. P-gp and NF-κB significantly decreased; however, p53 increased in FaDu/T + MG132 cells. These results suggested that the proteasome inhibitor MG132 reversed the malignant characteristics of FaDu/T by enhancing apoptosis and inhibiting P-gp. MG132 was also able to inhibit the nuclear translocation of NF-κB and increase the expression of p53.

BACKGROUND:The objective of this study was to evaluate the efficacy of Nimesulide, a selective cyclooxygenase-2 (COX-2) inhibitor, on the growth of hypopharyngeal carcinoma cells (FaDu) in vitro, and investigate its potential mechanism.METHODS:After FaDu cells were treated with graded concentrations of Nimesulide for divergent time, sensitivity of cells to drug treatment was analyzed by MTT assay. Morphological changes of FaDu cells in the presence of Nimesulide were observed by acridine orange cytochemistry staining. Proliferating cells were detected using the 5-Bromo-2'-deoxy-uridine (BrdU) incorporation assay. Following cells were subjected to Nimesulide (500 μmol/l) for 6 h, 12 h and 24 h, the percentage of apoptosis was examined by flow cytometry. We detected COX-2 and Survivin expression change by RT-PCR and Western blot, and analyzed the correlation of them with the growth of FaDu cells. Additionally, we also analyzed Caspase-3, Bcl-2 and Bax expressions as markers to investigate the related pathway of Nimesulide-indued apoptosis.RESULTS:Compared with the control group, the viabilities rates were decreased by Nimesulide in time- and dose-dependent manners, typical morphological changes of apoptotic cells were observed in the Nimesulide-treatment groups, Nimesulide could suppress the proliferation of FaDu cells significantly. The percentage of apoptosis in FaDu cells were markedly increased after Nimesulide-treatment for 6 h, 12 h and 24 h. Nimesulide down-regulated the Survivin and COX-2 expressions at mRNA and protein levels in FaDu cells. Additional analyses indicated that Bcl-2 expression was significantly decreased and the expressions of Caspase-3 as well as Bax were increased at both mRNA and protein levels.CONCLUSIONS:Based on the induction of apoptosis and suppression of proliferation, Nimesulide could inhibit the growth of FaDu cells. Furthermore, the suppression of Survivin expression may play an important role in Nimesulide-induced growth inhibition. Nimesulide could act as an effective therapeutic agent for hypopharyngeal carcinoma therapy.

OBJECTIVE:To investigate the expression of multidrug resistance gene ABCB1 and ABCG2 in FaDu cells (human hypopharyngeal carcinoma cell line) and the multidrug resistance (MDR) cell lines FaDu/T transformed from FaDu cells by taxol and underlying mechanisms of MDR. METHODS:The multidrug resistance sensitivities of FaDu and FaDu/T to cisplatin (DDP), 5-fluorouracil (5-FU), doxorubicin (Dox), and vincristine (VCR) were examined by methyl-thiazolyl-tetrazolium (MTT) assay. The mRNA and protein expressions of multidrug resistance genes ABCB1 and ABCG2 were analysed with RT-PCR, Western blot and laser confocal microscopy. JNK signal proteins were detected through Western blot. RESULTS:The multidrug resistance of FaDu/T cells to Taxol, DDP, 5-FU, ADM and VCR was more than that of FaDu cells. The expression of ABCB1 in FaDu/T cells was significantly higher than that in FaDu cells (t = 22.42, P < 0.05), but the expression of ABCG2 in FaDu/T cells was significantly lower than that in FaDu cells (t = 10.06, P < 0.05). JNK signal was inhibited in FaDu or FaDu/T cells and the inhibited JNK was reactivated by taxol or anisomycin (an activator for MAPK signal transduction pathways). Anisomycin down-regulated the expression of ABCB1 (F = 33.72, P < 0.05) and up-regulated the expression of ABCG2 (F = 220.16, P < 0.05) in FaDu/T cells, but not in FaDu/T cells pretreated by JNK inhibitor SP600125 (P > 0.05). CONCLUSION:The overexpression of ABCB1 and the down-regulation of ABCG2 in FaDu/T cells were the main features of MDR in hypopharyngeal carcinomas, in which JNK signal transduction pathways could play an important role.

Tumor stem cells (TSC), which are considered as likely candidates for the origin of cancer, are deduced to be responsible for tumor metastasis theoretically. We therefore investigated whether TSC were associated with lymph node metastasis in supraglottic carcinoma. Immunohistochemistry was performed for CD44, CD133, and LYVE-1 to detect TSC and lymphatic vessel density (LVD) in 66 primary supraglottic carcinoma tissue samples from 30 patients with lymph node metastasis (N+) and 36 patients without (N0). Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of CD44 and CD133 at mRNA and protein levels in N+ and N0 primary tumors. The LVD was 22.4 ± 10.26 in 30N+ and 6.8 ± 4.09 in 36N0 samples subjected to immunohistochemistry, which was associated with their clinical nodal stages. There were 43.33% CD44-positive and 93.33% CD133-positive samples in 30N+, and 13.89% CD44-positive and 44.44% CD133-positive samples in 36N0 ( P < 0.05). However, in each positive slide, there were only 5∼10% CD44-positive cells, but 70∼85% CD133-possitive cells. The expressions of CD44 and CD133 of N+ obtained through RT-PCR and Western blot were significantly higher than those of N0. These results suggest that TSC identified through CD44-positive cells in N+ were significantly higher than those in N0, indicating that TSC may be responsible for lymph node metastasis. CD133, whose expression is not restricted to TSC, may be unspecific for TSC identification in hypostatic supraglottic carcinoma.

The transcription factor TWIST is an important factor in regulation of the epithelial–mesenchymal transition (EMT), which represents the primary stages during the metastasis of tumors. To identify the role of TWIST in the regulation of metastasis in laryngeal carcinoma Hep-2 cells, we investigated whether the alteration of TWIST has an effect on the Hep-2 cells morphology and whether the alteration of TWIST has an effect on the expression of E-cadherin, N-cadherin as well as the ability of cell motion, migration, and invasion.

BACKGROUND:Twist is a highly conserved epithelial-mesenchymal transcription factor that has been reported to be a key factor in tumor malignancy, including lymph node metastasis. It represents the major step of dissemination and serves as a chief prognostic indicator of disease progression. However, the mechanism by which Twist regulates lymph node metastasis remains incompletely understood. Studies on the mechanism of metastasis are thus required for determining appropriate therapeutic strategies.METHODS:Immunohistochemistry for lymphatic vessel endothelial receptor 1 (LYVE-1), Ki-67, Twist, vascular endothelial growth factor C (VEGF-C), and vascular endothelial growth factor receptor 3 (VEGFR-3) was performed to detect lymphatic vessel density (LVD), cell proliferation levels and the expressions of Twist, VEGF-C, and VEGFR-3 were determined from 66 primary supraglottic carcinoma tissue samples from 36 patients with lymph node metastasis (pathological N+, pN+) and 30 patients without metastasis (pathological N0, pN0). Western blotting analysis of the proteins in pN+ and pN0 primary tumors was used to characterize the expressions of Twist, VEGF-C, and VEGFR-3 further.RESULTS:The LVD was 22.4 ± 10.3 in pN+ patients and 6.8 ± 4.1 in pN0 ones. For Ki-67, the number of proliferous cells in pN+ patients was greater than that in pN0 ones. Both, however, were associated with their clinical nodal stages. In pN+ patients, Twist, VEGF-C, and VEGFR-3 expressions were 86.11% (31/36), 80.56% (29/36), and 58.33% (21/36), respectively. These values were higher than those found for pN0 patients (i.e., 13/30, 11/30, and 7/30, respectively) (P < 0.05). Among the samples with Twist expression, 88.64% were VEGF-C-positive and 59.09% were VEGFR-3-positive. The pN0 counterparts were 4.55% and 9.09%, respectively (P < 0.05). The expressions of Twist, VEGF-C, and VEGFR-3 in pN+ patients obtained through Western blotting analysis were significantly higher than those in pN0 patients, and the levels of VEGF-C and VEGFR-3 were positively correlated with that of Twist.CONCLUSIONS:Twist expression correlates with lymph node metastasis. The mechanism involved in such a correlation may be related to lymphangiogenesis.

The transcription factor TWIST is an important factor in regulating epithelial-mesenchymal transition (EMT) and tumor metastasis. To explore the functions of TWIST in hypopharyngeal cancer, we investigated if overexpression of TWIST has an effect on FaDu cell morphology, and if alteration of TWIST has an effect on E-cadherin, N-cadherin, c-fos, MMP-9, as well as in cell migration, and the invasion ability of FaDu cells. Moreover, we also studied the relationship between TWIST overexpression and clinicopathological characteristics in hypopharyngeal cancer tissue samples by immunohistochemical assays. The results showed that overexpression of TWIST-induced morphological changes, such as occurrence of EMT. TWIST overexpression also increased cell migration and invasion ability, accompanied by an alteration of E-cadherin, N-cadherin, c-fos and MMP-9 expression. Furthermore, immunohistochemical assays showed that TWIST overexpression was related with tumor differentiation (P=0.038), tumor size (P=0.048) and lymph node metastasis (P=0.044). The data presented reveal that overexpression of TWIST plays a significant role in the metastasis of hypopharyngeal tumors, and alteration of TWIST has an effect on the EMT, c-fos and MMP-9 expression in FaDu cells. We conclude that TWIST promotes hypopharyngeal carcinoma metastasis, and the TWIST/c-fos/MMP-9 signaling pathway may play an important role in the metastasis of FaDu cells.

OBJECTIVE To investigate the different or similar characteristics between the hypopharyngeal carcinoma cell line(FaDu cells)and the multidrug resistance(MDR)cell lines(FaDu/T)induced by Taxol.METHODS Human FaDu cells were exposed in stepwise escalating concentration of Taxol until the resistant cell line was formed.The drug resistance was investigated by methyl-thiazolyl-tetrazolium(MTT)assay.The cell apoptosis was measured by staining cells with acridine orange(AO),Ho.33342 and PI staining.Meanwhile,the cell cycle distribution was quantified through flow cytometry.Reverse Transcription Polymerase Chain Reaction(RT-PCR)was conducted to detect mRNA levels of the drug resistance genes ABCB1 and apoptosis related genes Bax,Bcl-2,Caspase-3.The proteins levels were detected through Western blot.RESULTS Compared with parents FaDu cells,the drug resistance cells of FaDu/T had the biological characteristics as follows: ①They had a lower growth velocity;②Their mutidrug resistance ability was increased;③The percentage of cells in G0/G1 phases was increased while that in G2/M and S phase decreased,but the proportion of apoptosis cells had no prominent difference;④The expression of ABCB1 gene increased significantly;⑤The anti-apoptotic protein Bcl-2 increased prominently,while the apoptotic protein,Caspase-3 and Bax,decreased.CONCLUSION The high expression of ABCB1,Bcl-2 may be the critical reason of the chemotherapy resistance in FaDu/T;but the internal connection among various biological characteristics of tumor cells is worth to be further investigeated.

The major obstacle to tumor chemotherapy is drug resistance. In the present study, we investigated the characteristics of FaDu cells (a hypopharyngeal carcinoma cell line) with multidrug resistance (MDR) induced by Taxol. The resistant cell line, FaDu/T, was grown by exposing normal FaDu cells to escalating concentrations of Taxol stepwise for over 12 months. The multidrug resistant sensitivities of the FaDu/T cells to cisplatin (DDP), 5-fluorouracil (5-FU), doxorubicin (Dox) and vincristine (VCR) were investigated by methyl-thiazolyl-tetrazolium (MTT) assay. Cell apoptosis was measured by acridine orange and Hoechst 33342/propidium iodide double staining. Cell cycle distribution and the cell apoptosis index were quantified using flow cytometry. Reverse transcription-polymerase chain reaction (RT-PCR) was conducted to determine the mRNA levels of the MDR-related genes MDR1/ABCB1 and BCRP/ABCG2. Western blotting was used to assay the expression of MDR1/ABCB1 and BCRP/ABCG2 and the apoptosis-related proteins caspase-3, Bcl-2 and Bax. Compared with the FaDu cells, the drug resistance of FaDu/T cells to DDP, 5-FU, Dox and VCR was increased 8.99-, 21.96-, 31.42- and 10.00-fold, respectively. The percentages of FaDu/T cells in the G0/G1 and G2/M phases were increased while the cell percentage in the S phase decreased as compared with the percentages of FaDu cells. The anti-apoptotic ability increased prominently, as the index of apoptosis decreased. Furthermore, caspase-3, Bcl-2 and Bax expression was altered accordingly to resist apoptosis in the FaDu/T cells. MDR1/ABCB1 expression increased significantly at both the mRNA and protein levels, while BCRP/ABCG2 expression appeared to inversely affected, i.e. decreased, in a concentration-dependent manner. These -findings may provide theoretical support for the prevention of MDR in clinical cancer chemotherapy.

OBJECTIVE To explore the effects of overexpression of transcription factor Twist on the expression of E-cadherin and N-cadherin and invasion in a human laryngeal carcinoma cell line Hep-2. METHODS The well-constructed pcDNA3.1-Twist was transfected into Hep-2 cells by lipofectamine 2000. The expressions of Twist, E-cadherin and N-cadherin at protein level after transfection for 72 h were examined by Western-blotting. Morphological changes of Hep-2 cells after transfection was observed by reserved microscope. Cell invasion was measured by Transwell Chamber assay. RESULTS The expression of Twist at protein levels after transfection for 72h in Hep-2 cells was increased, with up-regulation of N-cadherin and down-regulation E-cadherin. There was a statistically significant difference between treatment and control group(P0.05). Hep-2 cells were undergoing epithelial-mesenchymal transition, their morphology switched from an apical-basolateral, polarized epithelial phenotype to a spindle-shaped, fibroblast-like mesenchymal phenotype. Number of invasion cells in pcDNA3.1-Twist transfectants was markedly increased compared to that of normal or pcDNA3.1 Hep-2 cells. Number of invasion cells were 85.33±6.66, 29.33±10.70 and 32.00±3.61 in above groups respectively(F=52.32, P0.05). CONCLUSION Twist, which could induce epithelial-mesenchymal transition and promote invasion in Hep-2 cells, may play its role through induction of N-cadherin and inhibiting E-cadherin expression.

在胚胎发育过程中,转录因子Twist可以促进细胞生长和分化,在成人阶段Twist基因的表达常处于沉默状态。近年来研究显示,在许多肿瘤中都发现了Twist存在表达异常,并且随着肿瘤的进展,其量的改变更加明显,因此断定Twist参与了肿瘤的发生、侵袭和转移过程。现在关于Twist调节肿瘤转移的具体机制还不是很明确,在其发挥作用的过程中受到了很多因子的调控,同时也调节了一些因子的表达,本文将这些相关因子做一综述。

OBJECTIVE:To investigate the effects of Nimesulide, a selective Cox-2 inhibitor, on the apoptosis, invasion and migration of hypopharyngeal carcinoma cell line (FaDu).METHODS:Viabilities of FaDu cells treated with various concentrations of Nimesulide were detected by MTT assay. Morphological changes were observed by acridine orange cytochemistry staining. Apoptosis was examined by flow cytometry. The ability of invasion and migration of cells was detected by Transwell chambers. The mRNA and protein expressions of Cox-2, MMP-9 and caspase-3 in response to Nimesulide were examined by RT-PCR and Western blot, respectively.RESULTS:MTT assay showed that the cell surviving rates significantly decreased in time- and concentration-dependent manners (P < 0.05). The typical morphological changes of apoptotic cells were observed. Percent of apoptosis after 6 h Nimesulide treatment was (32.4 ± 6.1)%. The metastatic cells were decreased by Nimesulide to about 20%. Nimesulide decreased the expressions of Cox-2 and MMP-9, whereas increased expression the of Caspase-3.CONCLUSION:Nimesulide could induce the apoptosis and inhibit metastasis of FaDu cells.

OBJECTIVETo explore the relationship between the expression of transcription factor TWIST and apoptosis of Hep-2 cells induced by paclitaxel.METHODSMorphological changes of Hep-2 cells were observed by reserved microscopy and acridine orange cytochemistry staining. Viability of Hep-2 cells treated with various concentrations of paclitaxel was detected by MTT assay. Apoptosis was examined by flow cytometry. The expressions of transcription factor TWIST at both mRNA and protein level in response to paclitaxel at 24 h, 48 h and 72 h were then examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively.RESULTSTypical morphological changes of apoptotic cells, i.e., cellular rounding-up, cytoplasmic contraction, chromatin condensation and, particularly, apoptotic body, the main morphological characteristic of apoptosis, were observed by reserved microscopy and acridine orange cytochemistry staining. The cell surviving rates significantly decreased in a concentration- and time-dependent manner as evidenced by MTT assay (P < 0.05). Percent of apoptosis after 24 h, 48 h or 72 h paclitaxel-treatment was (22.6 +/- 5.3)%, (38.7 +/- 7.9)% and (52.4 +/- 14.3)%, respectively, whereas the percent of control was (9.85 +/- 5.83)%. There existed a statistically significant difference between treatment and control (F = 12.621, P < 0.05). The expression of TWIST at both mRNA and protein levels for 24 h, 48 h or 72 h in the paclitaxel-induced apoptosis of Hep-2 cells were decreased by 16.7%, 46.8%, 76.9% (F = 10.407, P < 0.05) and 16.4%, 33.6%, 69.6% (F = 18.013, P < 0.05) respectively.CONCLUSIONSTWIST, which is significantly decreased in expression in response to paclitaxel in Hep-2 cells, may play a pivotal role in paclitaxel-induced apoptosis of Hep-2 cells.