Objective The specific roles of phosphorylated signal transducer and activator of transcription-3 (p-STAT3) and β-Catenin in laryngeal squamous cell carcinoma (LSCC) remain unclear. Methods In this study, the correlations between p-STAT3, β-Catenin, and clinicopathological characteristics were investigated using tissues and clinical data from 124 LSCC cases. Immunohistochemistry and immunofluorescence assays were used to examine p-STAT3 and β-Catenin expression and localization in these samples. Kaplan–Meier survival and Cox regression analyses were performed to evaluate the prognostic significance of these proteins. LSCC cell lines were treated with a STAT3 inhibitor (dihydroartemisinin) or activator (interleukin-6) to explore the mechanism of p-STAT3 and β-Catenin. Results There was an inverse correlation between p-STAT3 and β-Catenin expression in the LSCC samples. Patients with high p-STAT3 and low β-Catenin expression levels had significantly worse overall survival. Multivariate Cox regression analysis revealed that lymph node metastasis and β-Catenin expression were both independently correlated with unfavorable overall survival. Cell treatment with the p-STAT3 inhibitor inhibited the nuclear accumulation of β-Catenin, while p-STAT3 activator treatment could promote β-Catenin translocation to the nucleus. Conclusion Overall, our data indicate that p-STAT3 expression is associated with LSCC by promoting β-Catenin degradation. Keywords β-Catenin , epithelial-mesenchymal transition , laryngeal squamous cell carcinoma , STAT3 , prognostic indicator , biomarker

Objective The specific roles of phosphorylated signal transducer and activator of transcription-3 (p-STAT3) and β-Catenin in laryngeal squamous cell carcinoma (LSCC) remain unclear. Methods In this study, the correlations between p-STAT3, β-Catenin, and clinicopathological characteristics were investigated using tissues and clinical data from 124 LSCC cases. Immunohistochemistry and immunofluorescence assays were used to examine p-STAT3 and β-Catenin expression and localization in these samples. Kaplan–Meier survival and Cox regression analyses were performed to evaluate the prognostic significance of these proteins. LSCC cell lines were treated with a STAT3 inhibitor (dihydroartemisinin) or activator (interleukin-6) to explore the mechanism of p-STAT3 and β-Catenin. Results There was an inverse correlation between p-STAT3 and β-Catenin expression in the LSCC samples. Patients with high p-STAT3 and low β-Catenin expression levels had significantly worse overall survival. Multivariate Cox regression analysis revealed that lymph node metastasis and β-Catenin expression were both independently correlated with unfavorable overall survival. Cell treatment with the p-STAT3 inhibitor inhibited the nuclear accumulation of β-Catenin, while p-STAT3 activator treatment could promote β-Catenin translocation to the nucleus. Conclusion Overall, our data indicate that p-STAT3 expression is associated with LSCC by promoting β-Catenin degradation.

目的探讨沉默修复交叉互补基因1（excision repair cross complementary 1,ERCC1）表达对裸鼠人鳞状细胞癌移植瘤化疗增敏作用及其机制。方法 Balb/c纯系裸鼠背部皮下分别注入2×10~6个Hep-2细胞0.2 ml,制备裸鼠喉鳞状细胞癌移植瘤模型。实验随机分为空质粒对照组（A组）,顺铂化疗组（DDP组,B组）,顺铂化疗联合ERCC1 ShRNA组（DDP+ERCC1 ShRNA,C组）。测量并计算移植瘤体积,应用免疫组织化学方法检测喉癌Hep-2细胞移植瘤组织Ki67指数和ERCC1的表达,应用Western blot检测喉癌Hep-2细胞移植瘤组织ERCC1表达。结果移植瘤模型小鼠体积在C组于给药第15天和第20天明显减小,与B组相比差异有统计学意义（t值分别为13.103和17.022,P均＜0.01）。Ki67指数C组与B组相比明显降低,差异有统计学意义（t=3.794,P＜0.05）,ERCC1表达的免疫组织化学结果和Western blot结果均显示,B组与A组相比明显升高,两组相比差异有统计学意义（t值分别为4.919和6.345,P均＜0.01）;C组与B组相比明显降低,差异有统计学意义（t值分别为5.367和 6.463,P均＜0.01）。结论喉鳞状细胞癌裸鼠移植瘤体内实验证明抑制ERCC1表达对化疗有明显增敏作用。

Objective To explore whether dihydroartemisinin (DHA) can block interleukin (IL)-6-induced epithelial–mesenchymal transition (EMT) in laryngeal squamous cell carcinoma (LSCC). Methods The expression of SLUG, signal transducer and activator of transcription 3 (STAT3), and microRNA (miR)-130b-3p was measured. In addition, a dual-luciferase reporter assay was performed to examine the interaction of miR-130b-3p with STAT3. Results We found that IL-6 can promote EMT and invasion in LSCC cells, whereas DHA can inhibit these two processes. However, DHA alone does not influence EMT and cancer invasion. Furthermore, DHA upregulated miR-130b-3p, which can downregulate STAT3 and β-catenin protein expression and decrease the activity of the IL-6/STAT3 signaling pathway. Moreover, we found that miR-130b-3p can target STAT3 directly. Conclusions DHA can block IL-6-triggered EMT and invasion in LSCC, and during these processes, DHA increases miR-130b-3p expression to decrease the activation of the IL-6/STAT3 and β-catenin signaling pathways. These findings may provide new insights into strategies for suppressing and even preventing LSCC metastasis.

Background Polarized M2 macrophages are an important type of tumor-associated macrophage (TAM), with roles in the growth, invasion, and migration of cancer cells in the tumor microenvironment. Dihydroartemisinin (DHA), a traditional Chinese medicine extract, has been shown to inhibit the progression and metastasis of head and neck squamous cell carcinoma (HNSCC); however, the effect of DHA on cancer prevention, and the associated mechanism, has not been investigated in the tumor microenvironment. Materials and Methods First, human Thp-1 monocytes were induced and differentiated into M2 macrophages using phorbol 12-myristate 13-acetate (PMA), interleukin-6 (IL-6), and interleukin-4 (IL-4). Induction success was confirmed by cell morphology evaluation, flow cytometry, and quantitative real-time polymerase chain reaction (qRT-PCR). Then, DHA was applied to interfere with M2 macrophage polarization, and conditioned medium (CM), including conditioned medium from M2 macrophages (M2-CM) and conditioned medium from M2 macrophages with DHA (M2-DHA-CM), was obtained. CM was applied to Fadu or Cal-27 cells, and its effects on cancer invasion, migration, and angiogenesis were evaluated using transwell, wound-healing, and tube formation assays, respectively. Finally, Western blotting was used to evaluate the relationship between signal transducer and activator of transcription 3 (STAT3) signaling pathway activation and M2 macrophage polarization. Results Human Thp-1 monocytes were successfully polarized into M2-like TAMs using PMA, IL-6, and IL-4. We found that M2-like TAMs promoted the invasion, migration, and angiogenesis of HNSCC cells; however, DHA significantly inhibited IL-4/IL-6-induced M2 macrophage polarization. Additionally, as DHA induced a decrease in the number of M2-like TAMs, M2-DHA-CM inhibited the induction of invasion, migration, and angiogenesis of Fadu and Cal-27 cells. Finally, DHA inhibited M2 macrophage polarization by blocking STAT3 pathway activation in macrophages. Conclusion DHA inhibits the invasion, migration, and angiogenesis of HNSCC by preventing M2 macrophage polarization via blocking STAT3 phosphorylation.

BACKGROUND Accumulating evidence indicates that cancer stem cells (CSCs) are a minor subpopulation of cancer cells that may be the primary source of cancer invasion, migration, and widespread metastasis. MATERIAL AND METHODS We investigated the effects of dihydroartemisinin (DHA) on distant metastasis of laryngeal carcinoma and the relevant mechanism. In vitro, we used the Hep-2 human laryngeal squamous carcinoma cell line (Hep-2 cells) to assemble CSCs, using CD133 as the cell surface marker. Our data demonstrate that the CD133⁺ subpopulation of Hep-2 cells has greater invasion and migration capabilities than CD133⁻ cells. We also evaluated the effects of DHA, a newly defined STAT3 inhibitor, on the invasion and migration of CD133⁺ Hep-2 cells under hypoxia and IL-6 stimulation, both of which can activate STAT3 phosphorylation. RESULTS CSCs exhibited a significant decrease in the ability of migration and invasion upon the application of DHA, along with simultaneous alterations in related proteins, both in cultured cells and in xenograft tumors. The associated signaling proteins included phosphorylated STAT3 (p-STAT3), matrix metalloproteinase-9 (MMP-9), and E-cadherin, which are closely involved in cancer invasion and metastasis. In vivo, we found that DHA can reduce lung metastasis formation caused by CSCs and prolong survival in mice, and can inhibit STAT3 activation, downregulate MMP-9, and upregulate E-cadherin in lung metastatic tumors. CONCLUSIONS Taken together, our findings indicate that CSCs possess stronger invasive and metastatic capabilities than non-CSCs, and DHA inhibits invasion and prevents metastasis induced by CSCs by inhibiting STAT3 activation.

目的 探讨双氢青蒿素(DHA)抑制下咽癌Fadu细胞增殖的机制,为其应用于临床抗肿瘤治疗提供理论依据.方法应用含不同浓度葡萄糖(5.5、10、15、25、50、100 mM)培养基,培养Fadu细胞36 h,Western blot检测p-STAT3及内质网应激相关蛋白GRP78的表达情况.应用不同浓度(10、20、40、80、160μM)DHA在培养基糖浓度为25 mM条件下处理下咽癌Fadu细胞,24 h后用MTT比色法检测对细胞增殖的影响;Western blot检测p-STAT3、GRP78的表达情况.结果DHA抑制下咽癌Fadu细胞增殖,且具剂量依赖性;低糖培养基可以降低p-STAT3的表达,增加GRP78的表达;DHA抑制p-STAT3表达,低浓度DHA刺激GRP78表达,随着浓度逐渐增高则抑制其表达.结论DHA可以显著抑制下咽癌Fadu细胞的增殖,抑制p-STAT3的表达,诱导内质网应激,其作用机制可能与干扰细胞糖代谢密切相关.

目的 初步探索神经生长因子受体在喉癌Hep2细胞系的表达情况并研究相关的细胞生物学特性.方法 应用免疫细胞化学及免疫荧光染色法,检测p75NTR在喉癌Hep2细胞系中的表达;应用流式细胞仪检测人喉癌Hep2细胞系中呈p75NTR高表达及CD133高表达细胞的分布比例情况.结果 喉癌Hep2细胞系内小部分肿瘤细胞显示免疫染色强阳性,p75NTR强阳性显色的细胞部分处于旺盛的增殖分裂状态;大部分呈CD133强阳性的Hep2细胞也呈p75NTR强阳性.结论 p75NTR高表达于喉癌Hep2细胞系中具有较强增殖活力的细胞,p75NTR信号通路对支持或促进喉癌细胞增殖具有潜在作用.p75NTR高表达的喉癌Hep2细胞与肿瘤干细胞之间的关系密切,有待进一步深入研究.

目的 探讨应用RNA干扰技术沉默胶质瘤细胞转录因子1(Glioma-associated Oncogene Homolog 1,Gli1)基因表达对喉癌Hep-2细胞增殖影响极其机制.方法 应用脂质体法将Gli1小发夹RNA(small hairpin RNA,shRNA)转染到人喉癌Hep-2细胞,流式细胞术检测转染效率,四甲基偶氮唑蓝(MTT)法检测细胞增殖变化,Western blot法检测Gli1和cyclin D1蛋白表达.结果 Gli1蛋白表达在Gli1 shRNA组与空白对照组(t=15.565,P<0.01)和空质粒对照组(t=14.406,P<0.01)相比明显降低,统计学有显著差异.细胞增殖抑制率在Gli1 shRNA组与空白对照组(t=9.728,P<0.01)和空质粒对照组(t=9.649,P<0.01)相比明显增高,统计学有显著差异.cyclin D1蛋白表达在Gli1 shRNA组与空白对照组(t=23.045,P<0.01)和空质粒组(t=26.630,P<0.01)相比均明显降低.结论 RNA干扰技术沉默Gli1基因表达明显抑制喉癌Hep-2细胞增殖活性,其机制可能是通过降低cyclin D1蛋白表达.

OBJECTIVE To investigate the radiosensitization of combined inhibition of signal transducer and activator of transcription 3(STAT3) and hypoxia-inducible factor-1α(HIF-1α)on laryngeal squamous carcinoma of xenograft mice and its underlying mechanisms.METHODS Xenograft mice were divided into 5 groups randomly: control group(A), irradiation group(B), irradiation and AG490 group(C), irradiation and PX478 group(D), irradiation combined AG490 and PX478 group(E). The size of xenograft tumor was measured and calculated. The expression of Ki67 and HIF-1α was detected by immunohistochemical method. Western blot was used to detect the expression of PARP1.RESULTS The size of xenograft tumor in group E was smaller compared with that in group C and group D. There were significantly difference between them respectively (t=12.367,11.598,P=0.000). The expression of HIF-1α in group E was lower than that in group C and group D respectively, and there were significantly difference respectively(t=5.422, 3.000,P<0.05). Ki67 index in group E was lower compared with that in group C and group D respectively and there were significantly difference respectively (t=4.479, 4.352,P<0.05). The level of cleaved PARP-1 in group E was higher than that in group C and group D respectively and there were significantly difference respectively (t=5.507, 7.102,P<0.05). CONCLUSION Combined inhibition of STAT3 and HIF-1α can increase the radiosensitivity of human laryngeal squamous carcinoma in the xenograft mice.

Laryngeal squamous carcinoma (LSC) represents one of the refractory malignant tumors of head and neck squamous cell carcinoma (HNSCC), leading to high patient mortality and unsatisfactory overall 5-year survival.New therapeutic targets and modalities for effective chemoprevention and treatment are required to improve the survival of patients with LSC.Evidence from previous studies has suggested that proteasome inhibitors (PIs) possess effective antitumor activity and have been approved by the United States Food and Drug Administration (FDA) to treat myeloma.However, resistance of myeloma to PIs has been reported, which prevents PIs from their clinical uses in cancer treatment.So far, the underlying mechanisms of tumor cells anti-PIs effects remain unclear.In the present study, we found that constitutive activation of signal transducer and activator of transcription 3 (STAT3) was associated with clinicopathlologic factors in LSC patients, and persistent activation of STAT3 was found in Hep-2 laryngeal carcinoma cells.Moreover, we demonstrated that proteasome inhibitor MG-132 induces apoptosis and cell cycle arrest in Hep-2 cells, accompanied by increased activation of STAT3; knockdown of STAT3 expression by shRNA or application of STAT3 inhibitor AG490 potentiates the antitumor effects of MG-132 in vitro, which is attributed to the down-regulation of cyclin D1 and Bcl-2.Taken together, we identified that STAT3 activation plays a great role in therapeutic resistance to PIs in LSC; blocking STAT3 activation could potentiate the tumor killing effects of PIs in LSC or other malignancies involving STAT3 activation.Combined application of PIs and STAT3 inhibitor may implicate a promising strategy for managing LSC or even other HNSCC.

Objective:To investigate the effect of dihydroartemisinin (DHA) on the apoptosis of Fadu cells.Method:Fadu cells were treated with DMSO or different doses of DHA for 24 or 48 h.After that, IC50 values of DHA were calculated based on the cell viability tested via MTT assay, the cell morphology was observed,the percentage of apoptotic cells was analyzed with the Annexin V-FITC Apoptosis Detection Kit, and some important regulators of apoptosis, such as Bcl-2, Bcl-xl, Mcl-1, Bax, and C-PARP were determined by Western blotting.Result:Certain doses of DHA significantly inhibited the proliferation and induced apoptosis of Fadu cells in a dose and time dependent manners. DHA also downregulated the expression of antiapoptotic proteins (Bcl-2, Bcl-xl, and Mcl-1) and upregulated the expression of proapoptotic proteins (Bax and C-PARP).Conclusion:DHA remarkably inhibited proliferation and induction of apoptosis in Fadu cells via affecting proteins of Bcl-2 family. DHA may be a promising drug to treat hypopharyngeal carcinoma.

Developing drugs that can effectively block STAT3 activation may serve as one of the most promising strategy for cancer treatment. Currently, there is no putative STAT3 inhibitor that can be safely and effectively used in clinic. In the present study, we investigated the potential of dihydroartemisinin (DHA) as a putative STAT3 inhibitor and its antitumor activities in head and neck squamous cell carcinoma (HNSCC). The inhibitory effects of DHA on STAT3 activation along with its underlying mechanisms were studied in HNSCC cells. The antitumor effects of DHA against HNSCC cells were explored both in vitro and in vivo. An investigation on cooperative effects of DHA with cisplatin in killing HNSCC cells was also implemented. DHA exhibited remarkable and specific inhibitory effects on STAT3 activation via selectively blocking Jak2/STAT3 signaling. Besides, DHA significantly inhibited HNSCC growth both in vitro and in vivo possibly through induction of apoptosis and attenuation of cell migration. DHA also synergized with cisplatin in tumor inhibition in HNSCC cells. Our findings demonstrate that DHA is a putative STAT3 inhibitor that may represent a new and effective drug for cancer treatment and therapeutic sensitization in HNSCC patients.

OBJECTIVE:To investigate the effects of combined inhibition of signal transducer and activator of transcription 3 (STAT3) and hypoxia-inducible factor-1α (HIF-1α) in the enhancement of chemosensitivity of the model of human laryngeal squamous cacinoma in nude mice. METHOD:Model nude mice were divided into six groups randomly: control group(A) , cisplatin group(B) , cisplatin and AG490 group(C) , cisplatin and HIF-1α⁻/⁻ group (D), cisplatin combined AG490 and HIF-1α⁻/⁻ group (E), HIF-1α⁻/⁻ group (F) (only in calculating tumor inhibition rate). 3mg/kg cisplatin was administered by peritoneal injection for 3 days. Then cisplatin and 10 mg/kg AG490 were administered every other day for 12 days. The expression of Ki67 and HIF-1α was detected by immunocytochemical method. Western blot was used to detect the expression of p-STAT3. RESULT:The expression of HIF-1α in group C and group D were lower than that in group B, and there were significant difference respectively (t₁ = 2.782, t₂ = 3.873, P < 0.05); The expression of HIF-1α in group E was lower than that in group C and group D respectively, and there were significant difference respectively (t₁ = 6.140, t₂ = 3.667, P < 0.01). The expression level of p-STAT3 in group C was markedly lower compared with that in group B, and there were significant difference between them (t = 17.840, P < 0.01); There were no difference between the expression level of p-STAT3 in group D and that in group B (t = 0.038, P > 0.05); The expression level of p-STAT3 in group E was significantly lower compared with that in group C and group D respectively (P < 0.01). Tumor inhibition rate of group E was higher than that in group B, group C , as well as group D respectively and there were significant difference respectively (t₁ = 5.509, P < 0.01; t₂ = 3.422, P < 0.05; t₃ = 2.718, P < 0.05 ). Ki67 index of group E was lower than that in group B, group C as well as group D respectively and there were significant difference respectively(t₁ = 8.307, P < 0.01; t₂ = 3.736, P < 0.05; t₃ = 4.524, P < 0.01). CONCLUSION:Combined inhibition of STAT3 and HIF-1α could enhance chemo-sensitivity in the model of human laryngeal squamous cacinoma in nude mice.

Accumulating evidence from epidemiological, pharmacological and case control studies has shown that dihydroartemisinin (DHA), one of first-line antimalarial drugs recommended by World Health Organization (WHO), possesses antineoplastic activity and selective cytotoxicity to a variety of human cancer cell model systems. Although some antitumor mechanisms of DHA have been confirmed, the findings from the previous studies are insufficient to fully reveal the whole picture of tumor suppression by DHA. In a recent investigation, we demonstrated that DHA exhibits antitumor properties against a variety of human HNSCC cells both in vitro and in vivo. The underlying mechanism involves selective inhibition of Jak2/STAT3 signaling. By specific inhibition of STAT3 activation, DHA exerted the chemotherapeutic efficacy, including reduction in cell viability and migratory capability, along with induction of G1 phase cell cycle arrest and apoptosis in HNSCC cells. All of data suggested that DHA may be a potent inhibitor of STAT3 that can be potentially used to treat patients with HNSCC, as well as other human cancers harboring STAT3 activation.

OBJECTIVETo investigate the influence of signal transducer and activator of transcription 3 (Stat3) and hypoxia-inducible factor-lα (HIF-1α) on the resistance effect of laryngeal squamous cell carcinoma to radiation therapy and chemotherapy under the hypoxia circumstances.METHODWestern blot was used to test the expression of p-Stat3 and HIF-1α in the Hep-2 cells under the hypoxia conditions. MTT assay was used to test the proliferation of Hep-2 cells after radiation therapy and chemotherapy; the Hep-2 cells were suppressed expression of Stat3 and/or HIF-1α.RESULT(1) AG490 induced significant proliferation inhibition on Hep-2 cells and Hep-2HIF-1α-/- cells in vitro underthe hypoxia environments (P < 0.05); (2) Suppressing expression of Stat3 reduced the expression of HIF-1α protein (P < 0.05); (3) Combined inhibition of Stat3 and HIF-1α enhanced radio- and chemo-sensitivity in laryngeal squamous carcinoma cells under hypoxia.CONCLUSIONCombined inhibition of Stat3 and HIF-1α can further enhance radio- and chemo-sensitivity in laryngeal squamous carcinoma cells under hypixia compare than inhibiting Stat3 or HIF-1α alone. Effectively blocking of HIF-1α pathway and suppressing the expression of Stat3, would be an effective method to enhance radio- and chemo-sensitivity in laryngeal squamous carcinoma cells, which provides a new thought to reduce the resistance to treatment.

Although the expression of tumor necrosis factor receptors (TNFRs) has been associated with clinicopathologic features of some other cancers, their roles in hypopharyngeal squamous cell carcinoma (HPSCC) have not been documented. Forty-five HPSCC specimens were analyzed for the expression of TNFR1 and TNFR2 and its relationship with clinicopathologic factors. Interaction between the two receptors and its effects on TNF-α was investigated by neutralizing TNFR1 and upregulation of TNFR2. The results indicated that, in HPSCC specimens, the expression of TNFR1 but not TNFR2 is associated with clinical staging, T stage, cervical lymph node metastasis, and histologic grade in HPSCC. In Fadu cells, when conjugating with its receptors, TNF-α mediates proliferation effects, and neutralizing TNFR1 and/or upregulating TNFR2 evokes proliferation-inhibiting and apoptosis-inducing effects and potentiates cisplatin (DDP)-induced growth inhibition and apoptosis induction. In conclusion, interaction of TNFR1 with TNFR2 determines the biological characters of HPSCC, and TNFR1 may dominate this process. Moreover, interaction between the two receptors plays important roles in determining the fates of HPSCC cells and thus may serve as a therapeutic target for developing new therapeutic strategies for HPSCC.

Although the expression of tumor necrosis factor receptors (TNFRs) has been associated with clinicopathologic features of some other cancers, their roles in hypopharyngeal squamous cell carcinoma (HPSCC) have not been documented. Forty-five HPSCC specimens were analyzed for the expression of TNFR1 and TNFR2 and its relationship with clinicopathologic factors. Interaction between the two receptors and its effects on TNF-alpha was investigated by neutralizing TNFR1 and upregulation of TNFR2. The results indicated that, in HPSCC specimens, the expression of TNFR1 but not TNFR2 is associated with clinical staging, T stage, cervical lymph node metastasis, and histologic grade in HPSCC. In Fadu cells, when conjugating with its receptors, TNF-alpha mediates proliferation effects, and neutralizing TNFR1 and/or upregulating TNFR2 evokes proliferation-inhibiting and apoptosis-inducing effects and potentiates cisplatin (DDP)-induced growth inhibition and apoptosis induction. In conclusion, interaction of TNFR1 with TNFR2 determines the biological characters of HPSCC, and TNFR1 may dominate this process. Moreover, interaction between the two receptors plays important roles in determining the fates of HPSCC cells and thus may serve as a therapeutic target for developing new therapeutic strategies for HPSCC.

胶质细胞瘤转录因子1 (Glioma-associated oncogene homolog 1,Gli1)是在胚胎期细胞发育中有重要作用的Hedgehog (Hh)信号通路中的一个核转录因子,Hh信号转导通路蛋白在成体细胞中不表达Agyeman等[1]报道Hh信号转导通路在包括结肠癌在内的多种肿瘤组织中重新激活,并促进肿瘤的恶性增殖以及侵袭转移.本研究检测喉癌中Gli1和CD34蛋白的表达,并计数瘤内微血管密度(microvessel density,MVD),旨在探讨Gli1在喉癌组织中的表达及与肿瘤微血管形成之间的关系,以探讨Gli1在喉癌新生血管形成中的作用,为喉癌的基因治疗提供新靶点.

Objective To investigate the effect of silencing of S-phase kinase associated protein 2 (Skp2) by small hairpin RNA ( shRNA) in combination with chemotherapy on proliferation and apoptosis in laryngeal carcinoma cell line Hep-2 cells. Methods Laryngeal cancer cells were divided into pGPU6 group, Skp2 shRNA group, Skp2 shRNA with chemotherapy group, pGPU6 with chemotherapy group and chemotherapy group. After transfected with Skp2 shRNA, Hep-2 cells were cultured and received cisplatin 6 h after that. Forty-eight hours after cultured, the cell proliferation was assayed by MTT, and apoptosis rate and the expression of Skp2 and p27 protein were analyzed by flow cytometry. Results The expression of Skp2 protein in Skp2 shRNA group was significantly lower than that in pGPU6 group (P<0. 01). The expression of p27 protein in Skp2 shRNA group was higher than that in pGPU6 group (P<0. 05). The growth inhibition rate in Skp2 shRNA group with cisplatin at 0 mg/L, 1 mg/L, 2 mg/L and 3 mg/L were higher than those in pGPU6 group with cisplatin at 0 mg/L, 1 mg/L, 2 mg/L and 3 mg/L, respectively (P<0. 01). The apoptosis rate in Skp2 shRNA with cisplatin group (2 mg/L) was strikingly higher than that in pGPU6 with cisplatin group (2 mg/L)(P<0. 01). Conclusion Skp2 shRNA could inhibit the expression of Skp2 gene selectively and combining with chemotherapy might provide a new therapeutic approach to treatment of laryngeal carcinomas.