RESUMO
BACKGROUND: Activation of autophagy flux contributed to resistance of breast cancer (BC) cells to current chemotherapeutic drugs, which seriously limited their therapeutic efficacy and facilitated BC recurrence in clinic. However, the detailed mechanisms are still not fully understood. In the present study, we identified that inactivation of AMPK-ULK1 signaling cascade mediated protective autophagy sensitized BC cells to doxorubicin in vitro. METHODS: Cell counting kit-8 (CCK-8) assay and colony formation assay were performed to evaluate cell proliferation abilities. Trypan blue staining assay was used to examine cell viability, and Annexin V-FITC/PI double staining method was conducted to determine cell apoptosis. The autophagosomes in BC cells were observed and photographed by electronic microscope (EM). Western Blot analysis was employed to examine genes expressions at protein levels. RESULTS: The parental doxorubicin-sensitive BC (DS-BC) cells were exposed to increasing concentrations of doxorubicin to establish doxorubicin-resistant BC (DR-BC) cells, and the DR-BC cells were much more resistant to high-dose doxorubicin treatment compared to the DS-BC cells. Interestingly, high-dose doxorubicin specifically increased LC3B-II/I ratio, promoted autophagosomes formation and decreased p62 expression levels to facilitate autophagy in DR-BC cells, instead of DS-BC cells, and the autophagy inhibitor 3-methyladenine (3-MA) enhanced the cytotoxic effects of high-dose doxorubicin on DR-BC cells. In addition, we proved that high-dose doxorubicin triggered protective autophagy in DR-BC cells by activating AMPK-ULK1 pathway. Functionally, high-dose doxorubicin increased the expression levels of phosphorylated AMPK (p-AMPK) and ULK1 (p-ULK1) to activate AMPK-ULK1 pathway in DR-BC cells, and the inhibitors for AMPK (compound C) and ULK1 (SBI-0206965) blocked autophagy to promote cell death and slow down cell growth in DR-BC cells treated with high-dose doxorubicin. CONCLUSIONS: Collectively, our in vitro data indicated that blockage of AMPK-ULK1 signaling cascade mediated protective autophagy might be a promising strategy to increase doxorubicin sensitivity for BC treatment.
Assuntos
Proteínas Quinases Ativadas por AMP/fisiologia , Apoptose/efeitos dos fármacos , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/fisiologia , Autofagia/fisiologia , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Adenina/análogos & derivados , Adenina/farmacologia , Autofagia/efeitos dos fármacos , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologiaRESUMO
Astrocyte elevated gene-1 (AEG-1), a novel tumor-associated gene, was found overexpressed in many tumors. Therefore, our purpose is to estimate whether AEG-1 overexpression is a novel predictor of prognostic marker in metastatic ovarian tumors. Immunohistochemistry was used to estimate AEG-1 overexpression in metastatic ovarian tumors from 102 samples. The association between AEG-1 expression and prognosis was estimated by univariate and multivariate survival analyses with Cox regression. The log-rank test was used to identify any differences in the prognosis between the two groups. The median overall and progression-free survival rates of patients with tumors from gastrointestinal tract origin were 0.97 and 0.51 years, respectively. Similarly, survival rates of patients with tumors of breast origin were 2.68 and 1.96 years (P < 0.0001). Of 102 patients, 77 had high expression, and AEG-1 overexpression had a significant link of prognosis in metastatic ovarian patients (P < 0.01). On the other hand, medians of overall survival and progression-free survival of patients with tumors of gastrointestinal tract origin were significantly lower than those of patients with tumors of breast origin (P < 0.0001). Patients with metastatic ovarian tumors of breast origin had significantly better prognosis than those with the tumors from gastrointestinal tract primary malignancies. It is suggested that AEG-1 overexpression might be an independent prognostic marker of metastatic ovarian tumors.
Assuntos
Moléculas de Adesão Celular/análise , Neoplasias Ovarianas/patologia , Adulto , Idoso , Biomarcadores , Feminino , Humanos , Imuno-Histoquímica , Proteínas de Membrana , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias Ovarianas/química , Neoplasias Ovarianas/mortalidade , Prognóstico , Modelos de Riscos Proporcionais , Proteínas de Ligação a RNARESUMO
AIMS: We aimed to investigate the incidence rates and risk factors for different subgroups of central neck lymph node (LN) metastasis (prelaryngeal, ipsilateral paratracheal, pretracheal, and contralateral paratracheal) in unilateral papillary thyroid carcinoma (PTC) patients with clinically negative neck nodes (cN0). METHODS: We evaluated 184 patients from 2007 to 2009. The relationships between different subgroups of LN metastasis and clinical pathological factors were analyzed. RESULTS: The incidence rates of different central LN metastases were diverse. Multivariate analysis indicated that lymphovascular invasion, perithyroidal invasion, and tumor size were risk factors for ipsilateral paratracheal central LN metastasis; tumor size was an independent risk factor for pretracheal central LN metastasis, and pretracheal or/and ipsilateral paratracheal central LN metastasis were risk factors for contralateral paratracheal central LN metastasis. CONCLUSION: The extent of elective central LN dissection (CLND) should be decided based on different clinical pathological factors in cN0 PTC patients. Moreover, elective prelaryngeal CLND may be unnecessary.
Assuntos
Carcinoma/epidemiologia , Carcinoma/secundário , Linfonodos/patologia , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/secundário , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/cirurgia , Carcinoma Papilar , Criança , Feminino , Seguimentos , Humanos , Incidência , Modelos Logísticos , Excisão de Linfonodo , Linfonodos/cirurgia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Valor Preditivo dos Testes , Fatores de Risco , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Adulto JovemRESUMO
BACKGROUND: Liver receptor homolog 1 (LRH1) plays a vital role in several human cancers, but its role in ovarian cancer (OC) remains unclear. We aimed to explore the functions of LRH1 and its clinical relevance. METHODS: LRH1 expression was evaluated by immunohistochemistry and reverse transcription quantitative polymerase chain reaction (RT-qPCR). The effects of LRH1 on tumor cell proliferation, migration and epithelial-mesenchymal transition (EMT) were evaluated in vitro. Furthermore, bioinformatics analysis was applied to predict the functions of LRH1. RESULTS: RT-qPCR showed that LRH1 mRNA expression was higher in the invasive lesions (P < 0.05). LRH1 overexpression was extremely related with elevated International Federation of Gynecology and Obstetrics (FIGO) stage (P = 0.001), lymph node metastasis (P = 0.011), peritoneal metastasis (P = 0.001), and platinum resistance (P = 0.037). Furthermore, LRH1 expression was an independent prognostic index for disease-free survival in patients with OC (P = 0.041). LRH1 overexpression (P = 0.011), FIGO stage (P < 0.001), and ascites (P = 0.015) independently affected peritoneal metastasis in patients with OC. LRH1 knockdown significantly inhibited the proliferation, migration, and EMT of human OC cells (P < 0.05); however, it reversed cisplatin resistance. Bioinformatics analysis indicated that the functions of LRH1 were associated with the PRC1 complex, nuclear ubiquitin ligase complex, and Polycomb-group (PcG) proteins. CONCLUSIONS: This study provides evidence of the predictive value of LRH1 on peritoneal metastasis and poor outcome and highlights the potential role of LRH1 as a biomarker for the targeted therapy of OC. Furthermore, LRH1 promotes OC cell proliferation, migration, and EMT in vitro, and its functions may be associated with PRC1 complex, nuclear ubiquitin ligase complex, and PcG proteins.
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Podoplanin (PDPN) is an important positive regulator of platelet aggregation and functions as a lymphatic endothelial marker. PDPN has been observed to be expressed in human tumor tissues and various cancer cell lines. In the present study, PDPN expression in patients with primary osteosarcoma was assessed at the mRNA and protein levels, and the associations between PDPN expression and pulmonary metastasis (PM) and prognosis were examined. Reverse transcription-quantitative PCR (RT-qPCR) analysis was used to detect the expression levels of PDPN in primary osteosarcoma tissues and paired normal bone tissues (n=20 pairs). In addition, immunohistochemical analysis of PDPN expression was performed in 168 paraffin-embedded osteosarcoma tissue specimens and 23 matched normal tissues. The RT-qPCR results revealed higher mRNA expression levels of PDPN in patients with PM compared with patients without PM. Further survival analyses identified Enneking stage and PM as two independent prognostic indicators. Finally, univariate analysis revealed that high PDPN protein expression was significantly associated with Enneking stage and PM in patients with osteosarcoma.
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Human papillomavirus (HPV) is an etiological risk factor for oropharyngeal squamous cell carcinomas (OPSCC). Our study investigates the prevalence, prognostic, and clinicopathologic features of HPV-related oropharyngeal cancer in Northeast China and elucidates the involvement of p16 in the tumorigenesis and progression of OPSCC. Specimens from 1470 OPSCC patients collected from 2000 to 2016 were analyzed using the status of HPV by polymerase chain reaction (PCR) and p16 immunohistochemistry. Overexpression of p16 was observed in 81 (5.51%) of the 1470 cases, and HPV positive was present in 78 cases (5.31%) of the 1470 cases. HPV positive and p16 overexpression have a good concordance. However, we found that the etiological fraction of HPV in cancers of the OPSCCs was obviously lower in Northeast China than other cohorts previously reported. Interestingly, nearly 89% of patients with p16 expression were smokers, and nearly 70% of patients with p16 expression had a history of alcohol. Our study also demonstrates that p16 expression is significantly associated with early stage primary OPSCCs and the patients with p16 expression tend to show better survival following surgery and radiotherapy.
Assuntos
Biomarcadores Tumorais/análise , Inibidor p16 de Quinase Dependente de Ciclina/análise , Neoplasias Bucais/metabolismo , Neoplasias Orofaríngeas/epidemiologia , Infecções por Papillomavirus/epidemiologia , Adulto , Idoso , Biomarcadores Tumorais/genética , China/epidemiologia , Estudos de Coortes , Inibidor p16 de Quinase Dependente de Ciclina/genética , Feminino , Histocitoquímica , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/epidemiologia , Neoplasias Bucais/genética , Neoplasias Bucais/virologia , Neoplasias Orofaríngeas/genética , Neoplasias Orofaríngeas/patologia , Neoplasias Orofaríngeas/virologia , Orofaringe/química , Orofaringe/patologia , Papillomaviridae , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Fatores de RiscoRESUMO
IgA nephropathy (IgAN) is characterized by high serum IgA levels and IgA deposition in the renal mesangium. Recent research has indicated that pathogenic IgA may originate from affected tonsils, where present enhancement of IgA production by IgA class switching and immuno-activation. Tripterygium Wilfordii (TW) was found to be especially effective in IgAN by its' immunosuppression effect. Given this background, we investigated the mechanisms underlying the role of TW in the generation of IgA and IgA class switching in tonsillar GCs of IgAN patients. Immunohistochemistry and RT-PCR revealed that the expression of thymic stromal lymphopoietin (TSLP) and IgA inducing cytokines were decreased in the tonsils of IgAN patients with TW treatment compared with those without treatment, followed by significantly decreased of IgA-bearing cells. The location of TSLP and IgA inducing cytokines in tonsillar tissue was confirmed by double immunofluorescence. Importantly, TW inhibit TSLP and IgA production in isolated FDC-associated clusters. Serum TSLP levels were decreased and correlated with IgA downregulation in the tonsils and serum of IgAN patients. These data indicated that TW may be involved in IgA production in the tonsils of IgAN patients, inhibiting IgA class switching in IgAN patients through the cooperative roles of AID, TGF-ß1, BAFF, and APRIL, highlighting a promising strategy for therapeutic intervention in IgAN.
RESUMO
Immunoglobulin A (IgA) nephropathy (IgAN) is characterized by high serum IgA levels and IgA deposition in the renal mesangium. Previous studies suggest that elevated serum IgA partly originates from the tonsils. Here, we investigated the mechanisms of IgA production in the tonsils of patients with IgAN. Immunohistochemistry revealed that the number and relative percentage of IgA-bearing cells were significantly increased in the tonsils of IgAN patients. Compared with non-IgAN patients, enhanced IgA class switching and overexpression of thymic stromal lymphopoietin (TSLP), TSLP receptor (TSLPR), activation-induced cytidine deaminase (AID), transforming growth factor-ß1 (TGF-ß1), B cell-activating factor of the tumor necrosis factor family (BAFF), and a proliferation-inducing ligand (APRIL) were detected in follicular dendritic cells (FDCs) of tonsillar germinal centers from IgAN patients. Importantly, TSLP correlated with IgA production in isolated FDC-associated clusters. Serum TSLP levels were increased and correlated with IgA overexpression in the tonsils and serum of IgAN patients. These data indicated that TSLP overexpression in tonsillar FDCs may promote IgA class switching in IgAN patients through the cooperative roles of AID, TGF-ß1, BAFF, and APRIL. Therefore, interactions between TSLP in FDCs and IgA production in tonsils may be an important mechanism contributing to the pathogenesis of IgAN.
Assuntos
Citocinas/metabolismo , Células Dendríticas Foliculares/metabolismo , Glomerulonefrite por IGA/sangue , Imunoglobulina A/sangue , Switching de Imunoglobulina/genética , Tonsila Palatina/patologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Citocinas/sangue , Células Dendríticas Foliculares/patologia , Feminino , Centro Germinativo/metabolismo , Centro Germinativo/patologia , Humanos , Masculino , Microdissecção , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Interleucina-7/metabolismo , Adulto Jovem , Linfopoietina do Estroma do TimoRESUMO
In the present study, we isolated and screened an antitumor polysaccharide (PGP2a) from the roots of Panax ginseng. Chemical composition analysis indicated PGP2a was an acidic protein-polysaccharide. The average molecular weight was estimated to be 3.2 × 10(4)Da. According to gas chromatography (GC) result, PGP2a consisted of galactose, arabinose, glucose and galacturonic acid in the molar ratio of 3.7:1.6:0.5:5.4, respectively. MTT assay showed that PGP2a had a potent inhibitory effect on the growth of HGC-27 cells in a dose-dependent fashion. Furthermore, the number of HGC-27 cells arrested in G2/M phase, and the percentage of apoptotic cells were increased in response to PGP2a treatment along with concentration increasing. Moreover, western blotting analysis showed that protein expressions of Twist and AKR1C2 were suppressed by PGP2a, whereas an increase of NF1 was observed at protein level. Taken together, these findings suggested that PGP2a could be developed as a novel antitumor agent acting on Twist related gene for human gastric cancer therapy.
Assuntos
Apoptose/efeitos dos fármacos , Hidroxiesteroide Desidrogenases/metabolismo , Neurofibromina 1/metabolismo , Proteínas Nucleares/metabolismo , Panax/química , Polissacarídeos/farmacologia , Neoplasias Gástricas/patologia , Proteína 1 Relacionada a Twist/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Cromatografia em Gel , Ativação Enzimática , Humanos , Poli(ADP-Ribose) Polimerases/metabolismo , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Neoplasias Gástricas/metabolismoRESUMO
It was previously reported that an antitumor polysaccharide (PGPW1) was isolated from the root of Panax ginseng. To extend our study, we investigated here the anti-invasive and metastatic effects of PGPW1 on human gastric cancer cell line HGC-27 and tried to determine its possible mechanism of action. Both scratch wound-healing and Transwell assay identified that PGPW1 dose-dependently inhibited migration and invasiveness of HGC-27 cells. Furthermore, results of western blot showed that protein levels of Twist and AKR1C2 were inhibited by PGPW1, whereas an increase of NF1 was observed. Moreover, down-regulation of Twist expression by PGPW1 blocked epithelial-mesenchymal transition (EMT), characterized by a gain of epithelial cell markers, E-cadherin, and loss of the mesenchymal markers, vimentin and N-cadherin, at protein levels. Collectively, we confirmed that PGPW1 decreased migration and invasion of HGC-27 cells by regulation of Twist, AKR1C2, NF1, E-cadherin, vimentin and N-cadherin expression. In conclusion, PGPW1 may serve as a powerful chemopreventive agent against gastric cancer metastasis.
Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas Nucleares/biossíntese , Panax/química , Polissacarídeos/farmacologia , Neoplasias Gástricas/metabolismo , Proteína 1 Relacionada a Twist/biossíntese , Antígenos CD/biossíntese , Antígenos CD/genética , Caderinas/biossíntese , Caderinas/genética , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Hidroxiesteroide Desidrogenases/biossíntese , Hidroxiesteroide Desidrogenases/genética , Metástase Neoplásica , Neurofibromina 1/biossíntese , Neurofibromina 1/genética , Proteínas Nucleares/genética , Polissacarídeos/química , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Proteína 1 Relacionada a Twist/genética , Vimentina/biossíntese , Vimentina/genéticaRESUMO
The aim of this study was to investigate expression of CD147 and MMP-9 in triple-negative breast cancer (TNBC) so as to determine whether these two proteins may be correlated with poor prognosis of TNBC patients. We examined the expression levels of the CD147 and MMP-9 in 127 patients with TNBC and 30 patients with mammary gland fibroma using immunohistochemical staining before any treatments. Furthermore, we analyzed the correlation between the expression of these two proteins and various clinicopathologic factors including survival status of patients with TNBC. Positive stain of CD147 and MMP-9 was observed in all samples of TNBC. A statistically positive correlation was observed between the expression levels of CD147 and MMP-9 in TNBC tissues. The incidences of high expression were 48.0 % for CD147 and 53.5 % for MMP-9 in 127 TNBC tissues, respectively. High expression of either CD147 or MMP-9 was significantly correlated with clinical feature and shorter progression-free survival (PFS) (P(CD147) = 0.039; P(MMP-9) = 0.017) and overall survival (OS) (P(CD147) = 0.037; P(MMP-9) = 0.023). The expression levels of CD147 and MMP-9 are positively correlated with invasion, metastasis and shorter PFS/OS of TNBC. Patients with high expression of CD147 and MMP-9 had poor prognosis than TNBC patients with low expression.
Assuntos
Basigina/biossíntese , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Metaloproteinase 9 da Matriz/biossíntese , Adulto , Idoso , Basigina/análise , Biomarcadores Tumorais/análise , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Metaloproteinase 9 da Matriz/análise , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Receptores de Superfície CelularRESUMO
TWIST, a basic helix-loop-helix transcription factor, has been recently reported to play an important role in tumorigenesis of human cancer through converting the early stage tumors into invasive malignancies. Upregulation of TWIST is often found in cancer patients, especially those with shorter survival period and poor response to chemotherapy. Here we studied the functions of TWIST on regulating migration rate, apoptosis, and gene expression in gastric cancer cells. TWIST expression is elevated in MGC-803 and HGC-27 cells that exhibit high invasive potential; whereas it is reduced in BGC-823 and SGC-7901 cells that possess relatively low invasive content. To evaluate functional consequences of TWIST induction, we examined the effect of TWIST on cell migration and apoptosis. Overexpression of TWIST in BGC-823 cells resulted in increased migration content and decreased sensitivity to the arsenic oxide-induced cell death. Moreover, small interference RNA-mediated TWIST ablation in MGC-803 and HGC-27 cells showed suppressed migration ability, increased induction of apoptosis in response to arsenic oxide, and elevated cell cycle arrest. Furthermore, we found a negative correlation between the TWIST level and p53 level, probably due to transcriptional regulation. Our results have identified TWIST as a critical regulator of gastric cancer cell proliferation and migration, suggesting a potential therapeutic approach to inhibit the growth and metastasis of gastric cancer through inactivation of TWIST.
Assuntos
Apoptose/efeitos dos fármacos , Metástase Neoplásica , Proteínas Nucleares/fisiologia , Neoplasias Gástricas/metabolismo , Proteína 1 Relacionada a Twist/fisiologia , Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Invasividade Neoplásica , Proteínas Nucleares/genética , Neoplasias Gástricas/patologia , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Proteína 1 Relacionada a Twist/genéticaRESUMO
TWIST is an important transcription factor during embryonic development and has recently been found to promote the epithelial-mesenchymal transition (EMT) phenomenon seen during the initial steps of tumor metastasis. To further investigate the potential targets and interacting genes of TWIST in human gastric cancer, we performed microarray analysis to compare the gene expression profiles in HGC-27 cells, with or without small interfering RNA (siRNA)-mediated depletion of TWIST. Our results showed that NF1, RAP1A, SRPX, RBL2, PFDN4, ILK, F2R, ERBB3, and MYB were up-regulated, whereas AKR1C2, FOS, GDF15, NR2F1, ATM, and CTPS were down-regulated after TWIST depletion. Moreover, TWIST-depleted HGC-27 cells showed a reversal of the morphologic and molecular changes associated with EMT. These results provide evidence that TWIST regulates the expression of several genes involved in the differentiation, adhesion, and proliferation of gastric cancer cells. The role of TWIST in the development of certain types of gastric cancer is discussed.
Assuntos
Proteínas Nucleares/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Proteína 1 Relacionada a Twist/metabolismo , Sequência de Bases , Adesão Celular/genética , Diferenciação Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Primers do DNA/genética , Epitélio/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Mesoderma/patologia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , RNA Interferente Pequeno/genética , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/patologia , Proteína 1 Relacionada a Twist/antagonistas & inibidores , Proteína 1 Relacionada a Twist/genéticaRESUMO
OBJECTIVE: To investigate the resection range of mesorectum and rectum below the inferior margin of tumor for the total mesorectum excision (TME) in middle-low rectal cancer. METHODS: Sixty patients were enrolled in the study. After TME operation, serial 5 mm interval sections were made in specimens of middle-low rectal cancer. The retrograde metastasis of rectal cancer was observed by routine HE staining. RESULTS: The phenomena of retrograde metastasis in mesorectum were found in 15 cases, and the distance of retrograde metastasis was 0.5-4.0(2.47+/-1.06) cm, which was correlated with Dukes stage, lymph node metastasis and histological differentiation. The retrograde metastases in bowel were found in 11 cases, and the distance of retrograde metastasis was 0.5-4.0 (1.64+/-1.16) cm, which was correlated with histological differentiation. CONCLUSIONS: The distal mesorectum should be resected at least 4 cm when TME is carried out, and the distal bowel at least 2.5 cm. More than 5 cm mesorectum and bowel should be resected when advanced Dukes stage, extensive lymph node metastasis and poor histological differentiation occurred.