Pan Chi

Lentivirus-mediated RNA interference targeting WWTR1 in human colorectal cancer cells inhibits cell proliferation in vitro and tumor growth in vivo

WW domain-containing transcription regulator 1 (WWTR1) was initially identified as a transcriptional coactivator involved in the differentiation of stem cells as well as the development of multiple organs. Recently, WWTR1 has also been identified as a major component of the novel Hippo signalling pathway important for the development of breast and lung cancer. Here, we show for the first time that WWTR1 has an oncogenic function in colorectal cancer cell lines. Knockdown of WWTR1 by lentivirus-mediated RNA interference in human colorectal cancer cells significantly decreased cell proliferation and the colony formation of RKO cells in vitro and tumor growth in vivo. Furthermore, we found that the decreased proliferation was due to cell cycle arrest and increased apoptosis. In addition, efficient knockdown of WWTR1, demonstrated by quantitative real-time PCR, led to upregulation of ASNS and downregulation of SMAD3, LTBR, BAX and BAK1 in WWTR1 knockdown cells, suggesting that these genes may be involved in the repression of cell proliferation. Our findings indicate that WWTR1 is an oncogene and has an important role in the proliferation of colorectal cancer cells and in tumor growth in vivo.

A nomogram predicting pathological complete response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer: implications for organ preservation strategies

PURPOSE To determine predictors of pathological complete response (pCR) in locally advanced rectal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), and develop a predictive nomogram. METHODS A total of 522 locally advanced rectal cancer patients undergoing nCRT and curative resection between 2008 and 2014 were included. Uni- and multivariate analysis was performed to identify predictors of pCR. A nomogram was developed and validated by internal (n=425) and external validation (n=97). RESULTS With a median follow-up of 55 months, pCR was associated with better 5-year overall and disease-free survival, distant control, but similar local control. Logistic regression showed that post-CRT distance from the anal verge (OR =0.840, P = 0.022), post-CRT tumor size (OR = 0.565, P = 0.003), post-CRT circumferential extent of tumor (OR = 0.021, P < 0.001), pre-CRT CEA level (OR = 2.004, P = 0.033), and post-CRT CEA level (OR = 3.767, P = 0.038) were independently associated with pCR. A nomogram was developed with a C-index of 0.81 and 0.75 on internal and external validation, respectively. CONCLUSION pCR was associated with better long-term outcome. A nomogram was successfully developed to predict pCR. It could support decision-making in organ preservation strategies.Purpose To determine predictors of pathological complete response (pCR) in locally advanced rectal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), and develop a predictive nomogram. Methods A total of 522 locally advanced rectal cancer patients undergoing nCRT and curative resection between 2008 and 2014 were included. Uni- and multivariate analysis was performed to identify predictors of pCR. A nomogram was developed and validated by internal (n=425) and external validation (n=97). Results With a median follow-up of 55 months, pCR was associated with better 5-year overall and disease-free survival, distant control, but similar local control. Logistic regression showed that post-CRT distance from the anal verge (OR =0.840, P = 0.022), post-CRT tumor size (OR = 0.565, P = 0.003), post-CRT circumferential extent of tumor (OR = 0.021, P < 0.001), pre-CRT CEA level (OR = 2.004, P = 0.033), and post-CRT CEA level (OR = 3.767, P = 0.038) were independently associated with pCR. A nomogram was developed with a C-index of 0.81 and 0.75 on internal and external validation, respectively. Conclusion pCR was associated with better long-term outcome. A nomogram was successfully developed to predict pCR. It could support decision-making in organ preservation strategies.

Effect of Interval between Neoadjuvant Chemoradiotherapy and Surgery on Oncological Outcome for Rectal Cancer: A Systematic Review and Meta-Analysis

Aim. To evaluate the influence of interval between neoadjuvant chemoradiotherapy (NCRT) and surgery on oncological outcome. Methods. A systematic search was conducted in PubMed, the Cochrane Library, and Embase databases for publications reporting oncological outcomes of patients following rectal cancer surgery performed at different NCRT-surgery intervals. Relative risk (RR) of pathological complete response (pCR) among different intervals was pooled. Results. Fifteen retrospective cohort studies representing 4431 patients met the inclusion criteria. There was a significantly increased rate of pCR in patients treated with surgery followed 7 or 8 weeks later (RR, 1.45; 95% CI, 1.18–1.78; and P < 0.01 and RR, 1.49; 95% CI, 1.15–1.92; and P = 0.002, resp.). There is no consistent evidence of improved local control or overall survival with longer or shorter intervals. Conclusion. Performing surgery 7-8 weeks after the end of NCRT results in the highest chance of achieving pCR. For candidates of abdominoperineal resection before NCRT, these data support implementation of prolonging the interval after NCRT to optimize the chances of pCR and perhaps add to the possibility of ultimate organ preservation.

Identification of HOXB8 and KLK11 expression levels as potential biomarkers to predict the effects of FOLFOX4 chemotherapy

AIM To measure global gene expression in primary advanced colorectal cancer patients who have undergone fluorouracil, leucovorin and oxaliplatin (FOLFOX4) chemotherapy and screen valuable biomarkers to predict the effects of chemotherapy. MATERIALS & METHODS Samples from primary advanced colorectal cancer patients were collected. The effects of chemotherapy were evaluated, and patients were divided into an experimental group and a control group. Cancerous tissue gene expression profiles were detected by chip technology. Valuable biomarkers were screened by bioinformatic analysis. Immunohistochemical analysis was performed to characterize the pattern of HOXB8 and KLK11 expression. HOXB8 and KLK11 signal probe values were analyzed using receiver operating characteristic analysis. RESULTS There were differentially expressed genes in the two groups. HOXB8 and KLK11 proteins were observed in the nucleus and on the outside of the cancer cells, respectively. Their prediction accuracies were 79.9 and 76.7%, respectively. CONCLUSION HOXB8 and KLK11 may be classified as valuable biomarkers, as they can predict the effects of FOLFOX4 chemotherapy in primary advanced colorectal cancer patients.

Establishment of a Predictive Genetic Model for Estimating Chemotherapy Sensitivity of Colorectal Cancer with Synchronous Liver Metastasis

OBJECTIVE We examined the whole genome expression profile in advanced colorectal cancer (ACC) patients who had received FOLFOX4 chemotherapy to establish a genetic biomarker model predicting chemotherapy sensitivity. METHODS Eligible ACC patients were divided into two groups, based on postchemotherapy evaluation results: specifically, the sensitive group (experimental group) and the resistant group (control group). The genome expression profiles of colorectal cancer tissues were examined using DNA microarray analysis, and differential gene expression was identified using a significance analysis of the microarray. The probe signal log ratios were used to produce the area-under-the-curve, sensitivity, and specificity for candidate genes. Genes exhibiting differential expression and significant predictive power were used to simulate a genetic model for estimating chemotherapy sensitivity. RESULTS Totally, 30 ACC patients were eligible for the study, 13 assigned to the experimental group and 17 to the control group. In total, 30 genes showing significant differential expression were identified. Seven candidate genes (NKX2-3, FXYD6, TGFB1I1, ACTG2, ANPEP, HOXB8, and KLK11), which exhibited positive or negative correlations, were incorporated into a genetic model, with an overall accurate predication rate of 93.3%. CONCLUSIONS The predictive model involving the seven genes listed had high accuracy in estimating chemotherapy sensitivity to the FOLFOX4 regimen.

A nomogram to predict distant metastasis after neoadjuvant chemoradiotherapy and radical surgery in patients with locally advanced rectal cancer

To compare distant metastasis (DM) in locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (nCRT) and surgery alone, and to develop a predictive nomogram for DM following nCRT.

A new method of assessing the surgical margin in rectal carcinoma—using nonlinear optical microscopy

Nowadays, surgical resection is still the most effective treatment strategy for rectal carcinoma and one of the most important factors affecting whether the operation is successful or not is the surgical margin determination, especially in the distal rectal carcinoma which should take the sphincter-preserving issue into consideration. However, until recently no reliable evaluation method has been developed for this purpose. There are some shortcomings in intraoperative negative surgical margin assessment such as either lack of enough detailed information of biological tissues or the fact that it is time-consuming. Multiphoton microscopy (MPM)—nonlinear optical microscopy, which is based on the nonlinear optical process two-photon excited fluorescence (TPEF) and second harmonic generation (SHG), has the ability to label freely and noninvasively visualize tissue micro-architecture at the sub-cellular level. The advantage of providing high contrast and high resolution biomedical image in real time makes MPM have a wide range of applications in life sciences. In this study, we introduced MPM to identify the boundary between normal and abnormal rectal tissues. MPM images clearly exhibit biological tissue microstructure and its morphological changes in the regions of our interest, which enable it to determine the surgical margin in rectal carcinoma. It can be foreseen that once MPM imaging system is used in clinical examination, it will greatly improve the accuracy of surgical resection.

Knockdown of KLK11 inhibits cell proliferation and increases oxaliplatin sensitivity in human colorectal cancer.

It has been reported that kallikrein 11 (KLK11) is crucially involved in the development and progression of various types of cancer. However, the molecular mechanisms that underlie the involvement of KLK11 in aberrant colorectal cancer (CRC) cell growth remain largely unclear. The aim of the present study was to investigate the role of KLK11 and the effects of KLK11 on oxaliplatin (L-OHP) chemosensitivity by knocking down KLK11 in LOVO and HCT-8 cells. Loss-of-function assays revealed KLK11 inhibition significantly inhibited growth and induced apoptosis of CRC cells in vitro. Notably, further experiments found that knockdown of KLK11 expression increased the L-OHP chemosensitivity of CRC cells. KLK11 inhibition of increased L-OHP-induced apoptosis may be associated with activation of caspase-3 cleavage and the apoptosis signaling pathway. The present results indicated that KLK11 may be an potential target of interest for future research into therapies for CRC.

Knockdown of KLK11 reverses oxaliplatin resistance by inhibiting proliferation and activating apoptosis via suppressing the PI3K/AKT signal pathway in colorectal cancer cell

Introduction Kallikrein 11 (KLK11) plays a crucial role in drug-resistance to oxaliplatin (L-OHP) in the treatment of metastatic colorectal cancer (mCRC). The study aimed to investigate the role of KLK11 in chemoresistance, and to clarify the mechanism underlying reverse of L-OHP resistance by knockdown of KLK11. Materials and Methods Resistance to oxaliplatin was induced in HCT-8 (HCT-8/L-OHP) colorectal adenocarcinoma cell lines by exposing cells to increasing concentrations of L-OHP. MTT, RT-qPCR, and Western blot were used to evaluate the resistance to L-OHP. We then knocked down KLK11 in HCT-8/L-OHP cells to explore the mechanism through which KLK11 reverses L-OHP resistance. The mRNA and protein expression of KLK11 in tissues from mCRC patients were detected by RT-qPCR and immunohistochemistry. Results The drug resistance index (RI) of HCT-8/L-OHP cell line to L-OHP, 5-Fluorouracil (5-FU), Irinotecan (CPT-11), Vincristine (VCR) and Cis-diamminedichloroplatinum (CDDP) were 10, 5.35, 3.23, 1.28, and 6.64, respectively. Increased expression of multi-drug resistant genes ABCC1, ABCB1, GSTP1 and ERCC1 were detected in HCT-8/L-OHP cell line. Moreover, the activated PI3K/AKT pathway was related to L-OHP-resistance. Knockdown of KLK11 in HCT-8/L-OHP cell reversed L-OHP-resistance by inhibiting cell growth and activating apoptosis via suppressing the PI3K/AKT signaling pathway. Moreover, high expression of KLK11 in chemoresistant-patients was associated with lymph node metastases and histopathology. Conclusion KLK11 was highly expressed in chemoresistant-patients and L-OHP-resistant cell lines. Moreover, L-OHP resistance was associated with activated PI3K/AKT signal pathway. Knockdown of KLK11 can reverse L-OHP resistance by blocking PI3K/AKT signaling pathway.

Prognostic significance of neoadjuvant rectal score in locally advanced rectal cancer after neoadjuvant chemoradiotherapy and construction of a prediction model.

To evaluate the prognostic significance of neoadjuvant rectal (NAR) score after neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC), and to develop a nomogram predicting disease‐free survival (DFS).