Construction of a nomogram for central lymph node metastasis in papillary thyroid cancer based on gender grouping.

BACKGROUND: The status of central lymph nodes is crucial for determining the surgical approach to papillary thyroid carcinoma (PTC). Because of the differences between genders in central lymph node metastasis (CLNM), we aimed to construct separate predictive models for CLNM according to gender. METHODS: In our study, a total of 1258 PTC patients who underwent thyroid cancer surgery from September 2021 to March 2023 were analyzed retrospectively. The data were analysed univariately and multivariately using SPSS software grouped according to gender and nomograms of CLNM were plotted using R software. The variables included in this study were sex, Age, body mass index, Diabetes, chronic lymphocytic thyroiditis (CLT), Suspicious central lymph node (SCLN), A/T, Margin, Microcalcification (MC), BRAF, Number, Location, CLNM. RESULTS: The preoperative nomogram in male patients included four clinical variables: CLT, Margin, Number, Size. The preoperative nomogram of female patients included six clinical variables: Age, SCLN, Margin, MC, Number, Size. The calibration curves showed great agreement in both the training group and the validation group. The decision curve analysis showed the feasibility of nomogram in predicting CLNM in both man and woman. CONCLUSION: Based on the successful establishment of nomogram, we can analyze the variability of CLNM between male and female, which may provide clinicians with personalized clinical schemes in the treatment of PTC.

Prediction model of lymph node metastasis posterior to the right recurrent laryngeal nerve.

BACKGROUND: At present, it is still controversial whether lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) in papillary thyroid carcinoma (PTC) patients should be dissected. Failure to dissect metastatic lymph nodes results in continued metastasis from the positive lymph nodes to other regions. Our study aimed to establish a predictive model and predict the probability of metastasis of the lymph nodes posterior to the right recurrent laryngeal nerve (LNM-prRLN) in patients. METHODS: A total of 309 patients underwent surgery for thyroid cancer between May 2019 and September 2022. The risk factors were identified by univariate and multivariate analyses, and statistically significant risk factors identified in the multivariate analysis were included in the nomogram. We used the calibration curve and the receiver operating characteristic (ROC) curve to verify the accuracy of the prediction model. RESULTS: Multivariate analysis showed that irregular tumor margins (OR: 3.549, 95% CI 1.294-9.733, P = 0.014), extrathyroidal extension (OR: 4.507, 95% CI 1.694-11.993, P = 0.003), maximum tumor diameter > 1 cm (OR: 5.729, 95% CI 2.617-12.542, P < 0.001), overweight status (OR: 2.296, 95% CI 1.057-4.987, P = 0.036), high total cholesterol level (OR: 5.238, 95% CI 2.304-11.909, P < 0.001), and multifocality (OR: 11.954, 95% CI 5.233-27.305, P < 0.001) were independent risk factors for LNM-prRLN. The area under the ROC curve was 0.927. The calibration curve showed good agreement between the predicted and observed rates of LNM-prRLN. CONCLUSION: The probability of LNM-prRLN could be predicted by a nomogram based on the statistically significant risk factors identified in the multivariate analysis. This nomogram can guide clinicians when preoperatively evaluating the status of the LN-prRLN with regard to LNM-prRLN in PTC patients. For patients at high risk for LNM-prRLN, the preventive dissection of LN-prRLNs can be considered.

Nomograms for Prediction of High-Volume Lymph Node Metastasis in Papillary Thyroid Carcinoma Patients.

OBJECTIVE: The coexistence rate between chronic lymphocytic thyroiditis (CLT) and papillary thyroid carcinoma (PTC) is quite high. Whether CLT influences metastatic lymph nodes remains uncertain. High-volume lymph node metastasis is recommended as an unfavorable pathological feature. We aimed to investigate risk factors for high-volume central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) in PTC patients. STUDY DESIGN: Retrospective cohort study. SETTING: Changzhou First People's Hospital. METHODS: Clinicopathological characteristics of 1094 PTC patients who underwent surgery in our center from January 2019 to November 2021 were analyzed. RESULTS: The number of metastatic lymph nodes in the central compartment and lateral compartment were lower in the CLT group. We demonstrated that age, BRAF V600E, shape, and the number of foci were risk factors for high-volume CLNM in patients with CLT. For patients without CLT, sex, age, tumor size, number of foci, and margin were risk factors for high-volume CLNM. Tumor size, number of foci, location, and CLNM were all risk factors for high-volume LLNM in patients with or without CLT. Body mass index was only associated with high-volume LLNM in CLT patients. All the above factors were incorporated into nomograms, which showed perfect discriminative ability. CONCLUSION: Separate predictive systems should be used for CLT and non-CLT patients for a more accurate clinical assessment of lymph node status. Our nomograms of predicting high-volume CLNM and LLNM could facilitate risk-stratified management of PTC recurrence and treatment decisions.

Construction of prediction models for determining the risk of lateral lymph node metastasis in patients with thyroid papillary carcinoma based on gender stratification.

BACKGROUND: Lateral lymph node metastasis (LLNM) is associated with poor prognosis in patients with papillary thyroid cancer (PTC). The purpose of this study was to determine the risk factors for LLNM and establish prediction models that could individually assessed the risk of LLNM. METHODS: A total of 619 PTC patients were retrospectively analyzed in our study. Univariate and multivariate analysis were performed for male and female patients, respectively, to assess relationships between clinicopathological features and LLNM. By integrating independent predictors selected by binary logistic regression modeling, preoperative and postoperative nomograms were developed to estimate the risk of LLNM. RESULTS: LLNM was detected in 80 of 216 male patients. Of 403 female patients, 114 had LLNM. The preoperative nomogram of male patients included three clinical variables: the number of foci, tuner size, and echogenic foci. In addition to the above three variables, the postoperative nomogram of male patients included extrathyroidal extension (ETE) detected in surgery, central lymph node metastasis (CLNM) and high-volume CLNM. The preoperative nomogram of female patients included the following variables: age, chronic lymphocytic thyroiditis (CLT), BRAF V600E, the number of foci, tumor size and echogenic foci. Variables such as CLT, BRAF V600E, the number of foci, tumor size, ETE detected in surgery, CLNM, high-volume CLNM and central lymph node ratio were included in the postoperative nomogram. Above Nomograms show good discrimination. CONCLUSIONS: Considering the difference in the incidence rate of LLNM between men and women, a separate prediction system should be established for patients of different genders. These nomograms are helpful in promoting the risk stratification of PTC treatment decision-making and postoperative management.

LASSO-based machine learning models for the prediction of central lymph node metastasis in clinically negative patients with papillary thyroid carcinoma.

Background: The presence of central lymph node metastasis (CLNM) is crucial for surgical decision-making in clinical N0 (cN0) papillary thyroid carcinoma (PTC) patients. We aimed to develop and validate machine learning (ML) algorithms-based models for predicting the risk of CLNM in cN0 patients. Methods: A total of 1099 PTC patients with cN0 central neck from July 2019 to March 2022 at our institution were retrospectively analyzed. All patients were randomly split into the training dataset (70%) and the validation dataset (30%). Eight ML algorithms, including the Logistic Regression, Gradient Boosting Machine, Extreme Gradient Boosting (XGB), Random Forest (RF), Decision Tree, Neural Network, Support Vector Machine and Bayesian Network were used to evaluate the risk of CLNM. The performance of ML models was evaluated by the area under curve (AUC), sensitivity, specificity, and decision curve analysis (DCA). Results: We firstly used the LASSO Logistic regression method to select the most relevant factors for predicting CLNM. The AUC of XGB was slightly higher than RF (0.907 and 0.902, respectively). According to DCA, RF model significantly outperformed XGB model at most threshold points and was therefore used to develop the predictive model. The diagnostic performance of RF algorithm was dependent on the following nine top-rank variables: size, margin, extrathyroidal extension, sex, echogenic foci, shape, number, lateral lymph node metastasis and chronic lymphocytic thyroiditis. Conclusion: By incorporating clinicopathological and sonographic characteristics, we developed ML-based models, suggesting that this non-invasive method can be applied to facilitate individualized prediction of occult CLNM in cN0 central neck PTC patients.

A comparative analysis of eight machine learning models for the prediction of lateral lymph node metastasis in patients with papillary thyroid carcinoma.

Background: Lateral lymph node metastasis (LLNM) is a contributor for poor prognosis in papillary thyroid cancer (PTC). We aimed to develop and validate machine learning (ML) algorithms-based models for predicting the risk of LLNM in these patients. Methods: This is retrospective study comprising 1236 patients who underwent initial thyroid resection at our institution between January 2019 and March 2022. All patients were randomly split into the training dataset (70%) and the validation dataset (30%). Eight ML algorithms, including the Logistic Regression, Gradient Boosting Machine, Extreme Gradient Boosting, Random Forest (RF), Decision Tree, Neural Network, Support Vector Machine and Bayesian Network were used to evaluate the risk of LLNM. The performance of ML models was evaluated by the area under curve (AUC), sensitivity, specificity, and decision curve analysis. Results: Among the eight ML algorithms, RF had the highest AUC (0.975), with sensitivity and specificity of 0.903 and 0.959, respectively. It was therefore used to develop as prediction model. The diagnostic performance of RF algorithm was dependent on the following nine top-rank variables: central lymph node ratio, size, central lymph node metastasis, number of foci, location, body mass index, aspect ratio, sex and extrathyroidal extension. Conclusion: By combining clinical and sonographic characteristics, ML algorithms can achieve acceptable prediction of LLNM, of which the RF model performs best. ML algorithms can help clinicians to identify the risk probability of LLNM in PTC patients.

Influence of Obesity Parameters on Different Regional Patterns of Lymph Node Metastasis in Papillary Thyroid Cancer.

Objective: Obesity increases risk of thyroid cancer. However, the association between obesity and the progression of papillary thyroid cancer (PTC) remains controversial. This retrospective study aimed to explore the relationship between obesity and regional patterns of lymph node metastasis (LNM) in PTC. Methods: We retrospectively reviewed data from 1015 patients with PTC. We calculated obese parameters, such as body mass index (BMI), body fat percentage (BFP), and body surface area (BSA). Logistic regression models were used to assess associations between obese parameters and the rate of lymph node metastasis (LNM), number of LNM, pattern of LNM, and lymph node ratio (LNR). Results: Higher BMI was not associated with different regional patterns of LNM in PTC. In men with PTC, high BFP was an independent predictor of total LNM, central lymph node metastasis (CLNM), total lateral lymph node metastasis (LLNM), multiple lateral lymph node metastasis, and simultaneous metastasis in lateral compartment. In addition, male patients with high BFP had higher central LNR and higher number of CLNM. For women, high BSA was an independent predictor of LLNM and level IV metastasis. Female patients with high BSA had higher number of CLNM. Conclusion: BFP and BSA, possibly influenced by gender, were positively associated with the number and risk of LNM in different regions of PTC patients. However, BMI was not the predictor for aggressiveness of PTC in terms of LNM. Clinical decision-making for regional LNM in PTC patients should consider the factor of obesity.

Nomograms for the prediction of lateral lymph node metastasis in papillary thyroid carcinoma: Stratification by size.

Background: Lateral lymph node metastasis (LLNM) is a risk factor of poor prognosis in papillary thyroid cancer (PTC). We aimed to determine predictive factors and develop the nomograms for LLNM in patients with papillary thyroid microcarcinoma (PTMC) and macro-PTC. Methods: We reviewed the medical records of 1,106 patients who underwent surgery between January 2019 and January 2022. Patients were divided into a PTMC and a macro-PTC group. We developed preoperative and postoperative nomograms for predicting LLNM based on results of multivariate analysis. Internal calibration was performed for these models. Results: The number of metastatic lymph nodes in lateral compartment was higher in macro-PTC patients. LLNM was independently associated with gender, the number of foci, location, shape, and central lymph node metastasis (CLNM) in PTMC patients. For macro-PTC patients, chronic lymphocytic thyroiditis, the number of foci, location, margin, CLNM, and central lymph node ratio were all independent predictors for LLNM. All the above factors were incorporated into nomograms, which showed the perfect discriminative ability. Conclusion: The diameter of the tumor has an impact on the rate of LLNM. Separate predictive systems should be used for PTMC and macro-PTC patients for more accurate clinical assessment of lateral lymph node status. Through these nomograms, we can not only detect high-risk patients with occult LLNM preoperatively, but also form appropriate treatment protocols for postoperative management of PTC patients with different risks.

Nomograms to predict ipsilateral and contralateral central lymph node metastasis in clinically lymph node-negative patients with solitary isthmic classic papillary thyroid carcinoma.

BACKGROUND: Isthmus-originating papillary thyroid carcinoma has unique clinicopathological characteristics. There are no specific guidelines regarding the extent of surgery for isthmic papillary thyroid carcinoma. We aimed to evaluate the characteristics of clinically lymph node-negative patients with solitary isthmic papillary thyroid carcinoma and to determine the best surgical protocol for these patients. METHODS: A total of 904 patients diagnosed with solitary papillary thyroid carcinoma who underwent surgery were retrospectively reviewed. These patients were divided into the isthmic group (246 patients) or lobar group (658 patients). We compared the 2 groups and conducted a multivariate analysis to assess risk factors for ipsilateral and contralateral central lymph node metastasis in isthmic papillary thyroid carcinoma patients. Nomograms for predicting central lymph node metastasis in isthmic papillary thyroid carcinoma patients were developed and internal calibration was performed for these models. RESULTS: Isthmic papillary thyroid carcinoma patients have a significantly higher incidence of extrathyroidal extension and central lymph node metastasis than do lobar papillary thyroid carcinoma patients. For isthmic papillary thyroid carcinoma patients, sex, BRAF V600E mutation, chronic lymphocytic thyroiditis, tumor size, margin, and extrathyroidal extension were independent risk factors of ipsilateral central lymph node metastasis. Body mass index, BRAF V600E mutation, tumor size, location, and extrathyroidal extension were independent risk factors of contralateral central lymph node metastasis. All the above factors were incorporated into nomograms, which showed the perfect discriminative ability. CONCLUSION: Based on the predictive nomograms, we proposed a risk stratification scheme and corresponding individualized surgical treatment based on different nomogram scores. In the debate about prophylactic central neck dissection among clinically lymph node-negative patients with solitary isthmic papillary thyroid carcinoma, our nomograms provide the balance to avoid overtreatment and undertreatment through personal risk assessment.

A Nomogram Based on Clinical and Ultrasound Characteristics to Predict Central Lymph Node Metastasis of Papillary Thyroid Carcinoma.

Background: The status of lymph nodes in the central compartment is crucial to determining the surgical strategies for papillary thyroid carcinoma (PTC). We aimed to develop a nomogram for predicting central lymph node metastasis (CLNM). Methods: A total of 886 PTC patients who underwent total thyroidectomy or lobectomy with central neck dissection (CND) from July 2019 to June 2020 were retrospectively retrieved. Clinical and ultrasound features were collected. Univariate and multivariate analysis were performed to determine risk factors of CLNM. A nomogram for predicting CLNM was developed, internal and external calibration was performed for the established model. Results: Variables (sex, chronic lymphocytic thyroiditis, tumor size, the number of foci, tumor location, margin) significantly associated with CLNM were included in the nomogram. The nomogram showed excellent calibration in the training group and validation group, with area under curves of 0.806 (95% CI, 0.771 to 0.825), and 0.799 (95% CI, 0.778-0.813) respectively. Conclusion: Through this accurate and easy-to-use nomogram, the possibility of CLNM can be objectively quantified preoperatively. Clinicians can use this nomogram to evaluate the status of lymph nodes in PTC patients and consider prophylactic CND for those with high scores.

Synchronous papillary thyroid carcinoma and follicular thyroid carcinoma: case report and review of literature.

Collision tumor is a term denoting two histologically distinct tumor types occuring at the same anatomic site, which is a rare clinical entity. In the thyroid gland, collision tumors are rare. Here we report a case of the synchronous occurrence of follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma (PTC). The current case report describes a 40-year-old woman with synchronous FTC and PTC. Pathologists and surgeons should be aware of collision tumors to avoid possible misdiagnosis.

Diagnosis and Management of High-Grade Pancreatic Trauma: Report of 14 Cases.

The aim of this study was to review the diagnosis and operative management of cases of high-grade pancreatic trauma. A retrospective analysis was performed on 14 patients treated for high-grade pancreatic trauma at our institution between December 2008 and November 2013. The patients were treated for injuries resulting from blunt abdominal trauma. The main clinical data of the patients was analyzed, including time to diagnosis, initial serum amylase level, ultrasonography and abdominal computed tomography (CT) findings, pancreatic injury severity as scored according to the American Association for the Surgery of Trauma Organ Injury Scale, injury to other organs, operative treatment method, postoperative complications, and patient outcome. All 14 patients were diagnosed with severe (≥ grade III) pancreatic trauma. Diagnosis was confirmed in all seven hemodynamically stable patients that underwent CT and in 9/13 patients receiving ultrasound examination. All patients underwent surgical operations, including emergency pancreaticoduodenectomy (n = 8), splenectomy with distal pancreatectomy (n = 3), spleen-preserving distal pancreatectomy (n = 1), medial pancreatectomy with Roux-en-Y pancreaticojejunostomy (n = 1), and peripancreatic debridement and drainage (n = 1). Diagnosis was delayed beyond 24 h in two patients, both of whom underwent reoperative peripancreatic debridement and drainage, with one death. The complications included pancreatic fistula (n = 8), peripancreatic abscess (n = 2), hepatic artery hemorrhage (n = 1), gastrointestinal bleeding (n = 1), and intra-abdominal abscess (n = 1). CT is the most reliable method for diagnosing high-grade pancreatic trauma. Aggressive surgical therapy including pancreaticoduodenectomy is acceptable in hemodynamically stable patients.

Transcystic approach with micro-incision of the cystic duct and its confluence part in laparoscopic common bile duct exploration.

BACKGROUND: Laparoscopic transcystic common bile duct exploration has become a safe and ideal treatment of common bile duct stones. This study was designed to explore the clinical value of modified laparoscopic transcystic common bile duct exploration as a first line of treatment for patients with common bile duct stones. PATIENTS AND METHODS: A retrospective, case-control study of clinically comparable groups of patients who underwent the laparoscopic transcystic approach with micro-incision of the cystic duct and its confluence part in common bile duct exploration (LTM-CBD) (n=110) and laparoscopic common bile duct exploration (LCBD) (n=100) under the care of one surgeon was performed. All clinical data were analyzed retrospectively. RESULTS: There was no significant difference in terms of operation time between the two groups (P>.05). Postoperative hospital stay and abdominal drainage time were shorter in the LTM-CBD group than in the LCBD group (P<.05). Postoperative bile leakage was seen in 1 case (1 of 110) in the LTM-CBD group and 10 cases (10 of 100) in the LCBD group (P<.05). Twenty patients underwent T-tube drainage in the LCBD group, and primary closure was performed in the other patients; however, all cases in the LTM-CBD group underwent primary closure. The median follow-up was 12 months; 2 patients in the LCBD group who suffered from bile leakage presented with obstructive jaundice due to bile duct stenosis 6 months postoperatively. CONCLUSIONS: LTM-CBD, which can avoid postoperative T-tube drainage, decrease complications, shorten hospitalization time, and enhance the existing quality, is a minimally invasive, safe, and effective treatment.

Anatomical study of the anterolateral and posteromedial bundles of the posterior cruciate ligament for double-bundle reconstruction using the quadruple bone-tunnel technique.

BACKGROUND: Several techniques have been described for posterior cruciate ligament (PCL) reconstruction. However, double-bundle PCL reconstruction using the quadruple bone-tunnel technique has been seldom reported. The current study investigated this technique, focusing on the anatomy of the femoral and tibial insertions of the anterolateral (AL) and posteromedial (PM) bundles of the PCL. METHODS: Twenty-two fresh, healthy adult cadaveric knees were dissected and measured. The PCL was divided into the AL bundle and PM bundle at the insertion footprint. The insertion footprints of the AL and PM bundles, their location, size, and the clock positions were measured and described. RESULTS: On the femur, the clock position of the footprint of the AL bundle was 11:21 ± 0:23 (left) or 0:39 ± 0:23 (right), and the PM bundle was 9:50 ± 0:18 (left) or 2:10 ± 0:18 (right), with the knee flexed at 90 degrees. The distances from the center of the femoral insertions of the AL and PM bundles to the anterior cartilage margins of the medial femoral condyle were (7.79 ± 1.22) mm and (8.36 ± 1.63) mm, respectively. On the tibia, the vertical distances from the center of the tibial insertions of the AL and PM bundles to the tibial articular surface were (3.25 ± 1.20) mm and (6.91 ± 1.57) mm, respectively. CONCLUSIONS: These results have led to a better definition of the anatomy of the AL and PM bundle footprint of the PCL. The technique of double-bundle PCL reconstruction using quadruple bone-tunnel is feasible. Application of these data during PCL reconstruction using the quadruple bone-tunnel technique may help optimize knee stability.

Combination of Caspy2 and IP-10 gene therapy significantly improves therapeutic efficacy against murine malignant neoplasm growth and metastasis.

It has been shown that Caspy2, a zebrafish active caspase, can efficiently suppress the growth of malignant tumor. The present study was designed to test whether combined gene therapy with IP-10, a potent antitumor chemokine, and Caspy2 would improve therapy efficacy. Recombinant plasmid expressing both Caspy2 and IP-10 genes was mixed with DOTAP-cholesterol nanoparticles. Immunocompetent mice bearing CT26 colon carcinoma, B16-F10 melanoma, and 4T1 breast carcinoma were treated with the complex. We found that the combined gene therapy more efficiently inhibited tumor growth, while efficiently prolonging the survival of tumor-bearing animals, compared with monotherapy. Moreover, a significant reduction in spontaneous lung metastasis could be observed in the 4T1 breast carcinoma model. Infiltration of CD8(+) T lymphocytes was also observed. In addition, apoptotic cells were widely detected by TUNEL assay and caspase-3 immunostaining in coadministered tumor tissues. The combination treatment also successfully inhibited angiogenesis and tumor cell proliferation as assessed by CD31 and Ki-67 immunostaining, respectively. Furthermore, depletion of CD8(+) T lymphocytes could significantly abrogate the antitumor activity, whereas the depletion of CD4(+) cells or natural killer cells showed partial abrogation. Rechallenged CT26 tumors were rejected in all of the surviving mice treated by combination therapy. Our results suggest that combined therapy with Caspy2 and IP-10 can significantly enhance antitumor activity by acting as an immune response initiator, apoptosis inducer, and angiogenesis inhibitor, which may be important for further applications in clinical cancer therapy.

The effect of miR-7 on behavior and global protein expression in glioma cell lines.

Malignant glioma is a common cancer of the nervous system. Despite recent research efforts in cancer therapy, the prognosis of patients with malignant glioma has remained dismal. MicroRNAs are noncoding RNAs that inhibit the expression of their targets in a sequence-specific manner, and a few have been shown to act as oncogenes or tumor suppressors. Here, we aimed at exploring the precise biological role of microRNA-7 (miR-7) and the global protein changes in glioma cell lines transiently transfected with miR-7. Transfection of miR-7 into glioma cell lines causes inhibition of cell migration and invasion and suppression of tumorigenesis. Moreover, ectopic expression of miR-7 inhibits lung metastases of glioma in vivo. Among 65 protein spots with differential expression separated by 2-DE, 37 proteins were successfully identified by MS/MS analysis. Of those, the 25 downregulated proteins, which include 14-3-3ζ, eukaryotic translation initiation factor 5A (EIF5A), and annexin A4, may be downstream targets of miR-7, a finding that could elucidate some aspects of the behavior of glioma cells at the protein level. In conclusion, the absence of miR-7 function could cause downstream molecules to switch on or off, resulting in glioma development, invasion, and metastases. MiR-7-based gene treatment may be a novel anti-invasion therapeutic strategy for malignant glioma.

Efficient inhibition of human colorectal carcinoma growth by RNA interference targeting polo-like kinase 1 in vitro and in vivo.

Polo-like kinase 1 (PLK1) showing a high expression in various kinds of tumors is considered a candidate target for cancer therapy. The aim of our study was to explore the effects of silencing PLK1 gene on human colorectal carcinoma cell line HCT-116 in vitro and in vivo. In vitro, the plasmids generating short hairpin RNA (shRNA)-targeting PLK1 were transfected into HCT-116 by using FugeneHD reagent, and the silencing potency was measured by RT-PCR, western blot, flow cytometry, and Caspase-Glo 3/7 assay, respectively. In vivo, the growth inhibition capacity of PLK1-shRNA on HCT-116 xenograft was measured in nude mice. Then, the silencing effect of PLK1 was analyzed by RT-PCR, western blot, and immunohistochemistry, respectively. Apoptosis, angiogenesis, and proliferation in tumor tissues were measured by TUNEL, CD31, and PCNA stain, respectively. The RNA interference targeting PLK1 significantly decreased the expression of PLK1 in vitro. More importantly, anti-PLK1 treatment in HCT-116 xenograft decreased tumor weight by 81.58% compared with the control group (p<0.001), accompanied with decreased PLK1 mRNA and protein expression, increased cell apoptosis, and reduced angiogenesis and proliferation (p<0.001). Our study showed that knockdown of PLK1 by shRNA might be the potential therapeutic approach against human colorectal carcinoma.

RNA interference-mediated silencing of focal adhesion kinase inhibits growth of human malignant glioma xenograft in nude mice.

FAK (focal adhesion kinase), which plays a pivotal role in mediating cell proliferation, survival and migration, is frequently overexpressed in human malignant glioma. The expression of FAK increases with the advance of tumour grade and stage. Based on these observations, we hypothesized that attenuation of FAK expression may have inhibitory effects on the growth of malignant glioma. In the present study, human glioma cell line U251 was transfected with plasmids containing U6 promoter-driven shRNAs (small-hairpin RNAs) against human FAK using cationic liposome. The effects of FAK knockdown in U251 cells in vitro were analysed by using flow cytometry and PI (propidium iodide)-staining assays. Based on the encouraging in vitro results with FAK silencing, plasmids encoding FAK-targeted shRNA were encapsulated by DOTAP (dioleoyltrimethylammonium propane):Chol (cholesterol) cationic liposome and injected via tail vein to evaluate its therapeutic efficiency on suppressing tumour growth in a human glioma xenograft model. PCNA (proliferating-cell nuclear antigen), CD34 immunostaining and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay were used to assess the changes in tumour angiogenesis, apoptosis and proliferation respectively. The results indicated that DOTAP:Chol cationic liposome could deliver therapeutic plasmids systemically to tumour xenografts, resulting in suppression of tumour growth. Treatment with plasmid encoding FAK-targeted shRNA reduced mean tumour volume by approx. 70% compared with control groups (P<0.05), accompanied with angiogenesis inhibition (P<0.05), tumour cell proliferation suppression (P<0.05) and apoptosis induction (P<0.05). Taken together, our results demonstrated that shRNA-mediated silencing of FAK might be a potential therapeutic approach against human malignant glioma.