Knockdown of long non-coding RNA XIST suppresses nasopharyngeal carcinoma progression by activating miR-491-5p.

Dysregulated long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play key roles in the development and progression of human cancers. X-inactive specific transcript (XIST), an lncRNA, is known as an oncogene in multiple tumors. However, the roles of XIST and its related miRNAs in nasopharyngeal carcinoma (NPC) are poorly understood. In this study, we found that XIST expression was significantly upregulated in NPC tissues and cell lines. Knockdown of XIST inhibited NPC cell proliferation and invasion and induced apoptosis in vitro, as well as suppressed NPC tumor growth in vivo. Further analysis revealed that XIST and miR-491-5p interact with and repress each other. XIST may function as an endogenous miR-491-5p sponge to regulate the target gene of miR-491-5p. Taken together, these results provide a comprehensive view of the XIST/miR-491-5p axis in human NPC cells and may provide a new therapeutic target for treating NPC.

Indirect computed tomography lymphography identifies lymph node metastasis in rabbit pyriform sinus VX2 carcinoma.

Indirect computed tomography lymphography (CT-LG) could be used to determine the regional spread of cancer and assess lymphatic function by the interstitial delivery of diagnostic agents. Few studies have been reported on its use in pyriform sinus carcinoma. The aim of the present study was to establish the rabbit VX2 tumor as a model for pyriform sinus carcinoma and to observe its neck lymph node metastasis by indirect CT-LG. VX2 tumor tissue suspension was transplanted into the pyriform sinus submucosa of 15 rabbits under direct laryngoscope. Rabbits were randomly placed into one of three groups, each comprised of five rabbits. Observation of the tumor growth and neck lymph node metastases were taken on days 14 (group 1), 21 (group 2) and 28 (group 3) following transplantation using the method of indirect CT-LG. VX2 tumors were transplanted successfully in all rabbits. Deep cervical lymph nodes were enhanced clearly in indirect CT-LG. The contrast agent filling defected appeared on the metastasis nodes while the lymph node without metastasis was smooth. The metastasis rates of deep cervical lymph nodes were 100% in all three groups on CT-LG. The CT attenuation value of CT-LG reached peak values of 400 and 600 Hu at 1 and 3 min after the injection, which then decreased gradually. In this study, CT-LG could demonstrate the internal architecture of lymph nodes and their lymphatic vessels, and therefore may have the advantages of radiological methods such as B ultrasound, CT, magnetic resonance imaging and positron emission tomography.

Correlative study of indirect computed tomography lymphography using iopamidol and histopathology in a cervical lymph node metastasis model.

OBJECTIVES/HYPOTHESIS: To investigate the potential usefulness of indirect computed tomography lymphography (CT-LG) with iopamidol in the detection of cervical lymph node metastases in a VX2 rabbit tongue cancer model. STUDY DESIGN: Randomized controlled trial. METHODS: Thirty-seven rabbits were randomly divided into control (n = 7) and tongue tumor-bearing (n = 30) groups. In the control group, indirect CT-LG was performed with 0.5- and 0.25-mL injections of iopamidol in the right and left tongue submucosa, respectively. In the tumor-bearing group, indirect CT-LG with 0.5 mL of iopamidol was performed on day 11 (n = 8), 14 (n = 8), 21 (n = 8), or 28 (n = 6) after carcinoma transplant. The correlation between indirect CT-LG and histopathology was investigated. RESULTS: In normal rabbits, oval or round enhanced cervical lymph nodes in each side of the neck were visualized by indirect CT-LG. In tumor-bearing rabbits, one enhanced lymph node on each side of the neck was visualized with or without filling defects in all rabbits except two on day 28 in which lymph nodes were not enhanced. The sensitivity, specificity, accuracy, and positive and negative predictive values for using filling defects on CT-LG as a diagnostic criterion were 77.4%, 77.8%, 77.6%, 80%, and 75%, respectively. Indirect CT-LG detected 84.6% of 2- to 6-mm intranodal tumor deposits. CONCLUSIONS: Indirect CT-LG may be useful for differentiating metastatic from nonmetastatic lymph nodes.

[Establishment of the rabbit VX2 tumor as a model for pyriform sinus carcinoma and observation of its biological features].

OBJECTIVE: To establish the rabbit VX2 tumor as a model for pyriform sinus carcinoma and to observe its biological features. METHODS: VX2 tumor was implanted into the pyriform sinus of 15 rabbits by direct laryngoscope. Fifteen rabbits were randomized into 3 groups (average of 5 rabbits per group). Observation of the tumor growth and evaluation of the histopathological characterization were taken on one group each at the of time 14, 21 and 28 days after transplantation respectively. RESULTS: Tumors were found grown in the pyriform sinus of all 15 rabbits with a success implantation rate of 100%. Dysphagia, body weight loss, rhinorrhea and short of breath appeared in the rabbits 28 days after transplantation. The metastasis rates of deep cervical were 100% in all three groups. The metastasis rates of submandibular lymph nodes were 3/5, 4/5 and 5/5 in 14-day, 21-day and 28-day group respectively. The metastasis rates of paratracheal lymph nodes were 0, 4/5 and 5/5 in 14-day, 21-day and 28-day group respectively. There were opposite side lymph node metastasis of deep cervical, submandibular and paratracheal in 4, 3 and 5 rabbits on 14, 21 and 28 days after transplantation respectively. The median diameter for deep cervical, submandibular and paratracheal neck lymph nodes were 1.50, 0.60 and 0.0 cm in 14 days; 1.60, 0.80 and 0.50 cm in 21 days; 1.80, 0.8 and 0.65 cm in 28 days (P > 0.05). CONCLUSIONS: The animal model for pyriform sinus carcinoma is established successfully. The metastasis of deep cervical lymph node could be induced from day 14 after VX2 transplantation.

Cervical lymph node metastasis model of pyriform sinus carcinoma.

OBJECTIVE: To establish a cervical lymph node metastasis model of pyriform sinus VX2 carcinoma and investigate its metastatic features. METHODS: VX2 tumor tissue suspension was transplanted into the pyriform sinus submucosa of 15 rabbits under direct laryngoscopy. Rabbits were randomly placed into 1 of 3 groups, each comprised of 5 rabbits. Health evaluation and histopathological analysis were performed on days 14 (group 1), 21 (group 2), and 28 (group 3) after transplantation. RESULTS: VX2 tumors were transplanted successfully in all rabbits. Dysphagia, weight loss, rhinorrhea, and dyspnea were observed 28 days after transplantation. Deep cervical lymph node metastasis occurred in all rabbits at all time points. The rate of submandibular lymph node metastasis was 60% in group 1, 80% in group 2, and 100% in group 3. The rate of paratracheal lymph node metastasis was 0% in group 1, 80% in group 2, and 100% in group 3. CONCLUSIONS: A model of metastatic pyriform sinus carcinoma was established. This model could be used in future studies evaluating diagnostic and treatment methods.

[Cervical lymph node metastasis of pyriform sinus carcinoma].

OBJECTIVE: To investigate the characteristic of cervical lymph node metastasis of pyriform sinus carcinoma. METHOD: One hundred and two pyriform sinus carcinoma patients who accepted treatments in the EENT Hospital of Fudan University from 1990 to 2006 were reviewed retrospectively. All of them did not have any treatment and received surgical treatment in our hospital. Stage was made according to the standard of International Union Against Cancer (UICC)in 1997. The distribution of cervical lymph node was confirmed by CT scanning and pathology. RESULT: The rates of lymph node metastasis were 16.7% , 59.4%, 70.8% and 63.6% for patients with T1 disease, T2, T3 and T4 (P <0.05), respectively, and 62.7% (64/102) for the whole patients. The bilateral metastasis rate were 2.70% (1/37), 12.5% (6/48) and 18.1% (2/11) for T2, T3 and T1, respectively (P <0.05). The occurrence of cervical lymph node metastasis was 3.87% in the level I , 33.55% in the level II, 30.97% in the level III, 25.16% in the level IV, 5.16% in the level V, 1.29% in the level VI (P <0.05). Fourteen patients with cN0 stage had modified neck dissection and 10 patients had lymph node metastasis (71.4%). The lymph node metastasis of cN0 and cN1 was all in the level II, level III and level IV. And cN2 and cN3 also had some in the level I, level V and level VI. CONCLUSION: T2, T3 and T4 all had high rates for lymph node metastasis while T3, T4 were easier for contralateral metastasis. T3, T4 and contralateral metastasis were easier to surpassing the lymph node envelope. The lymph node metastasis of cN0 and cN1 was all in the level II, level III and level IV. And cN2 and cN3 also had some in the level I, level V and level VI.