Endoscopic mucosal resection-precutting vs conventional endoscopic mucosal resection for sessile colorectal polyps sized 10-20 mm.

BACKGROUND: The optimal method to remove sessile colorectal lesions sized 10-20 mm remains uncertain. Piecemeal and incomplete resection are major limitations in current practice, such as endoscopic mucosal resection (EMR) and cold or hot snare polypectomy. Recently, EMR with circumferential precutting (EMR-P) has emerged as an effective technique, but the quality of current evidence in comparative studies of conventional EMR (CEMR) and EMR-P is limited. AIM: To investigate whether EMR-P is superior to CEMR in removing sessile colorectal polyps. METHODS: This multicenter randomized controlled trial involved seven medical institutions in China. Patients with colorectal polyps sized 10-20 mm were enrolled and randomly assigned to undergo EMR-P or CEMR. EMR-P was performed following submucosal injection, and a circumferential mucosa incision (precutting) was conducted using a snare tip. Primary outcomes included a comparison of the rates of en bloc and R0 resection, defined as one-piece resection and one-piece resection with histologically assessed clear margins, respectively. RESULTS: A total of 110 patients in the EMR-P group and 110 patients in the CEMR group were finally evaluated. In the per-protocol analysis, the proportion of en bloc resections was 94.3% [95% confidence interval (CI): 88.2%-97.4%] in the EMR-P group and 86% (95%CI: 78.2%-91.3%) in the CEMR group (P = 0.041), while subgroup analysis showed that for lesions > 15 mm, EMR-P also resulted in a higher en bloc resection rate (92.0% vs 58.8% P = 0.029). The proportion of R0 resections was 81.1% (95%CI: 72.6%-87.4%) in the EMR-P group and 76.6% (95%CI: 68.8%-84.4%) in the CEMR group (P = 0.521). The EMR-P group showed a longer median procedure time (6.4 vs 3.0 min; P < 0.001). No significant difference was found in the proportion of patients with adverse events (EMR-P: 9.1%; CEMR: 6.4%; P = 0.449). CONCLUSION: In this study, EMR-P served as an alternative to CEMR for removing nonpedunculated colorectal polyps sized 10-20 mm, particularly polyps > 15 mm in diameter, with higher R0 and en bloc resection rates and without increasing adverse events. However, EMR-P required a relatively longer procedure time than CEMR. Considering its potential benefits for en bloc and R0 resection, EMR-P may be a promising technique in colorectal polyp resection.

Limonin enhances the radiosensitivity of nasopharyngeal carcinoma cells via attenuating Stat3-induced cell stemness.

The inhibitory effects of limonin have been disclosed in various tumors, however, its roles in nasopharyngeal carcinoma (NPC) progression are never been revealed. In the current work, we collected NPC cells with a higher stemness compared with bulk cells through isolating the side population (SP) cells. It was found that limonin exhibited a stronger inhibitory effect on SP cells than that in bulk cells, which was evident by a lower IC50 value. Additionally, limonin attenuated the stemness and migration ability of SP cells with the higher stemness, characterized as decreasing the spheroid formation ability, expression of stemness markers and migration ability. Moreover, the proportion of SP cells in G0 phase was remarkably higher than that in bulk cells. Notably, upon limonin treatment, the proportion of SP cells in G0 was decreased and S/G2/M increased. Furthermore, limonin enhanced the radiosensitivity of NPC cells. The mechanistic studies based on RNA-sequencing analysis revealed that limonin inhibited the gene transcription driven by Stat3 (signal transducer and activator of transcription 3) and an activator of Stat3 (Colivelin or IL-6) rescued the inhibitory effects of limonin. Therefore, these results demonstrate that limonin could reduce the stemness of NPC cells and thus the radiosensitivity through suppressing Stat3 transcriptional activity.

Construction and identification of small hairpin RNA plasmids targeting neuropilin-1 gene and their inhibitory effect on human nasopharyngeal carcinoma CNE-2Z cell proliferation in vitro and in vivo.

We observed the effects of small hairpin RNA (shRNA) plasmids targeting neuropilin-1 (NRP-1) gene on human nasopharyngeal carcinoma (NPC) CNE-2Z cell growth in vitro and in vivo. Three fluorescein-labeled shRNA eukaryotic expression vectors targeting NRP-1 gene, including pSilencer-shRNA1, pSilencer-shRNA2 and pSilencer-shRNA3 were constructed. The three plasmids were, respectively, transfected into human NPC CNE-2Z cells. The most effective plasmid was injected into xenograft tumors in nude mice. The sequencing for these recombinant plasmids was consistent with that of designed shRNA templates. Green fluorescence was seen in the transfected CNE-2Z cells and xenograft tumors in nude mice. MTT assay indicated that CNE-2Z cell proliferation was significantly inhibited. PT-PCR and Western blot displayed that both mRNA and protein of NRP-1 gene were all decreased, particularly in the cells treated with shRNA3. At the end of the experiment, xenograft tumors in plasmid group (0.599 ± 0.002 cm(3)) were significantly inhibited with a tumor inhibition rate of 48.6 %, as compared to those in negative (1.141 ± 0.013 cm(3)) and blank control groups (1.165 ± 0.308 cm(3)) (all P < 0.05). shRNA targeting NRP-1 gene can effectively inhibit human NPC CNE-2Z cell proliferation in vitro and in vivo. This provides an experiment basis for NPC gene therapy.

[Effect of HDAC6 down-regulation on the growth of xenografted human laryngeal carcinoma cell line Hep-2 in nude mice and underlying mechanism].

OBJECTIVE: To study the effect of histone deacetylation 6 (HDAC6) siRNA on the growth of xenografted human laryngeal squamous cell carcinoma cell line Hep-2 in nude mice and underlying mechanism. METHODS: Laryngeal squamous cell carcinoma cell line Hep-2 cells were subcutaneously injected to the back of nude mice and transplanted tumor model was established after one week. Nude mice was divided into three groups including blank control group, empty vector group and HDAC6 siRNA group, and the tumor growth was observed. Ki-67 proliferation index was detected by immunohistochemistry. Western blot, in situ hybridization and immunohistochemistry were used to detect the mRNA and protein expressions of HDAC6 in xenograft. The expressions of Bcl-2 and Bax proteins were examined by Western blotting. Cell apoptosis was detected by TUNEL. RESULTS: The mean volume of xenograft transfected with HDAC6 siRNA was less than that of xenograft transfected with empty vector or that of xenograft with blank control treatment (P < 0.05). HDAC6 siRNA effectively down-regulated the expressions of HDAC6 mRNA and the expressions of HDAC6 and Bcl-2 proteins, but up-regulated the expression of Bcl-2 protein in xenografts, with significant differences (all P < 0.05). The proliferation index of Ki-67 in HDAC6 siRNA transfection group was significantly lower than that in blank control group or empty vector group (P < 0.05). TUNEL assay demonstrated that HDAC6 evidently evoked cell apoptosis (P < 0.05). CONCLUSION: HDAC6 siRNA could effectively inhibited the growth of xenografted human laryngeal carcinoma cell line Hep-2 in nude mice, down-regulate the expressions of HDAC6 and bcl-2, and up-regulate the expression of bax.

[Down-regulation of histone deacetylase 2 induces cell apoptosis and inhibits cell proliferation and migration of laryngeal squamous cell carcinoma cells].

OBJECTIVE: To investigate the effects of histone deacetylase 2 (HDAC2) expression on cell proliferation, apoptosis and migration of laryngeal squamous cell carcinoma (LSCC) Hep-2 cells. METHODS: HDAC2 siRNA and control siRNA were transfected into LSCC Hep-2 cells by lipofectamine 2000, and cells were divided into three experimental groups: untreated group, control siRNA group and HDAC2 siRNA transfection group. Western blotting was utilized to detect the expression of HDAC2 protein in Hep-2 cells. Cell proliferation and apoptosis were investigated by CCK-8 kit and flow cytometry, respectively. Boyden chamber was used to study cell migration. Expressions of cell apoptosis and cell migration related proteins were detected by Western blotting. RESULTS: HDAC2 siRNA significantly down-regulated the expression of HDAC2 protein in LSCC Hep-2 cells. Down-regulation of HDAC2 expression coincided with an inhibition of cell proliferation and migration along with an induced cell apoptosis of Hep-2 cells. Moreover, down-regulation of HDAC2 expression significantly increased the expressions of caspase-3 and caspase-9 proteins but decreased the expressions of matrix metalloproteinases (MMP)-2 and MMP-9 proteins. CONCLUSIONS: HDAC2 may play a pivotal role in the initiation and development of LSCC. Down-regulation of HDAC2 expression mediates cell apoptosis. Cell migration inhibition may be tightly associated with overexpression of caspase-3 and caspase-9 along with down-regulation of MMP-2 and MMP-9 expressions.

Various presentations of fourth branchial pouch sinus tract during surgery.

CONCLUSION: A recurrent neck abscess or acute suppurative thyroiditis should arouse suspicion of fourth branchial pouch sinus. Complete surgical excision is usually curative. The classification of sinus tract according to the area where it is emerging from the larynx may be helpful in identifying the tract during surgery. OBJECTIVE: To describe our experience of the diagnosis and management of fourth branchial pouch sinus and elucidate three different emerging pathways of the sinus tract during surgery. METHODS: Retrospective case series with eight patients who were diagnosed with fourth branchial pouch sinus between January 2007 and July 2011 at the First Affiliated Hospital of Zhengzhou University. RESULTS: Six patients presented with recurrent neck abscess, two presented with acute suppurative thyroiditis. All patients had barium swallow and sinus tract was delineated in six cases. All eight patients underwent surgical excision of the sinus tract. Three different emerging pathways of the sinus tract were identified during surgery. The tract could penetrate the thyroid cartilage near the inferior horn, the inferior pharyngeal constrictor muscle or the cricothyroid membrane when it emerged from the larynx. The recurrent laryngeal nerve was commonly dissected to avoid inadvertent damage. Hemithyroidectomy was performed in six patients. All eight are currently asymptomatic.

[Diagnosis and management of congenital pyriform sinus fistula].

OBJECTIVE: To explore the clinical presentation and management principles of congenital pyriform sinus fistula. METHODS: Seven sequential cases of congenital pyriform sinus fistula (CPSF) treated between January 2007 and January 2011 were reported. The clinical presentation were recurrent left lower neck abscess or acute suppurative thyroiditis. All of these patients had past histories of misdiagnosis ranged from 3 years to 11 years. All the patients had undergone incision and drainage several times. In acute infection period, these patients received incision and drainage, after inflammation subsided, were treated with definitive surgery. RESULTS: After barium swallow study and CT examination in the quiescent stage of infection, 5 patients could be seen fistula in the pyriform, all the patients were found scar tissue near the left thyroid lobe, 4 patients received direct laryngoscope examination and 3 of them could be found inner orifice near the apex of pyriform sinus, fistula and the involved lobe of thyroid were successfully excised without permanent recurrent laryngeal nerve injury or hypothyroidism. All the patients had an uneventful recovery and remained symptom free from 5 months to 40 months. CONCLUSIONS: The clinical history of recurrent low neck inflammatory episodes in patients, especially on the left side, should raise the suspicion of CPSF, investigation using barium swallow in combination with CT scanning is useful. CPSF can be treated by excising the fistula and involved lobe of thyroid.

[Inhibitory effects of small interfering RNA targeting c-myc in combination with 5-fluorouracil on the growth in vitro and in vivo].

OBJECTIVE: To observe the effects of small interfere RNA (siRNA) targeting the c-myc in combination with 5-fluorouracil (5-Fu) on the growth of Hep-2 cells in vitro and in vivo. METHODS: Hep-2 cells transfected with or without c-myc siRNA were treated with 5-Fu for 48 h. C-myc protein levels in Hep-2 cells were detected using the Western blot. The cell cycle was analyzed by flow cytometry. Hep-2 cells were subcutaneously inoculated into the back of BALB/c nude mice to establish the implanted laryngeal squamous carcinoma model. PBS, c-myc siRNA, and 5-Fu, alone or in combinations were administered i.p. The mice were sacrificed after the treatments and the tumor masses were removed to determine the tumor volume and weight. The inhibitory rate was calculated. Expression of c-myc in tumor tissue was detected by immunocytochemistry and cell apoptosis was analyzed by terminal transferase dUTP nick end labeling (TUNEL). RESULTS: The protein levels of c-myc decreased after transfected with c-myc siRNA. C-myc siRNA-transfected cells showed an increase in the percentage of cells in the GO-G1 phase and a decrease in the percentage of cells in the S phase. When combined with 5-Fu, the results were improved. The tumor growth was faster in the control group and was significantly slower in the c-myc siRNA plus 5-Fu group than that in the c-myc siRNA group or 5-Fu group (P < 0.05). The tumor weight in the c-myc siRNA plus 5-Fu group was significantly smaller than that in the c-myc siRNA or 5-Fu group (P < 0.05). Immunohistochemistry showed that c-myc siRNA inhibited the expression of c-myc in tumor tissues in the c-myc siRNA group and c-myc siRNA plus 5-Fu group (P < 0.05). The number of apoptotic cells in the c-myc siRNA plus 5-Fu group was higher than those in the c-myc siRNA groups (P < 0.05). CONCLUSIONS: C-myc siRNA inhibits the expression of c-myc in Hep-2 cells and in the tumor tissues of nude mice. C-myc siRNA combined with 5-Fu inhibits the growth of implanted laryngeal squamous carcinoma and promotes cell apoptosis. C-myc could become a novel target for the treatment of laryngeal squamous carcinoma.