Feilin Cao

Assessment of a Novel VEGF Targeted Agent Using Patient-Derived Tumor Tissue Xenograft Models of Colon Carcinoma with Lymphatic and Hepatic Metastases

The lack of appropriate tumor models of primary tumors and corresponding metastases that can reliably predict for response to anticancer agents remains a major deficiency in the clinical practice of cancer therapy. It was the aim of our study to establish patient-derived tumor tissue (PDTT) xenograft models of colon carcinoma with lymphatic and hepatic metastases useful for testing of novel molecularly targeted agents. PDTT of primary colon carcinoma, lymphatic and hepatic metastases were used to create xenograft models. Hematoxylin and eosin staining, immunohistochemical staining, genome-wide gene expression analysis, pyrosequencing, qRT-PCR, and western blotting were used to determine the biological stability of the xenografts during serial transplantation compared with the original tumor tissues. Early passages of the PDTT xenograft models of primary colon carcinoma, lymphatic and hepatic metastases revealed a high degree of similarity with the original clinical tumor samples with regard to histology, immunohistochemistry, genes expression, and mutation status as well as mRNA expression. After we have ascertained that these xenografts models retained similar histopathological features and molecular signatures as the original tumors, drug sensitivities of the xenografts to a novel VEGF targeted agent, FP3 was evaluated. In this study, PDTT xenograft models of colon carcinoma with lymphatic and hepatic metastasis have been successfully established. They provide appropriate models for testing of novel molecularly targeted agents.

Differential response to EGFR- and VEGF-targeted therapies in patient-derived tumor tissue xenograft models of colon carcinoma and related metastases

Heterogeneity in primary tumors and related metastases may result in failure of antitumor therapies, particularly in targeted therapies for the treatment of cancer. In this study, patient-derived tumor tissue (PDTT) xenograft models of colon carcinoma with lymphatic and hepatic metastases were used to evaluate the response to EGFR- and VEGF-targeted therapies. Our results showed that primary colon carcinoma and its corresponding lymphatic and hepatic metastases have a different response rate to anti-EGFR (cetuximab) and anti-VEGF (bevacizumab) therapies. However, the underlying mechanism of these types of phenomenon is still unclear. To investigate whether such phenomena may result from the heterogeneity in primary colon carcinoma and related metastases, we compared the expression levels of cell signaling pathway proteins using immunohistochemical staining and western blotting, and the gene status of KRAS using pyrosequencing in the same primary colon carcinoma and its corresponding lymphatic and hepatic metastatic tissues which were used for establishing the PDTT xenograft models. Our results showed that the expression levels of EGFR, VEGF, Akt/pAkt, ERK/pERK, MAPK/pMAPK, and mTOR/pmTOR were different in primary colon carcinoma and matched lymphatic and hepatic metastases although the KRAS gene status in all cases was wild-type. Our results indicate that the heterogeneity in primary colon carcinoma and its corresponding lymphatic and hepatic metastases may result in differences in the response to dual-inhibition of EGFR and VEGF.

Surgical treatment of retrorectal tumors: a retrospective study of a ten-year experience in three institutions.

BACKGROUND/AIMS The relative rarity and anatomical position of retrorectal tumors may lead to difficulty in diagnosis and surgical management. METHODOLOGY This was a retrospective review of 93 patients who had resection of retrorectal tumors between 2002 and 2011. RESULTS All patients in this study were treated with excision of the retrorectal tumors. Surgical approach included transsacral approach (78 cases), transabdominal approach (12 cases) and combined approach (3 cases). Seventy-two benign lesions (77.4%) and 21 malignant (22.6%) were confirmed by histological examination. The 72 benign cases included dermoid cysts (26 cases), simple cysts (12 cases), teratomas (12 cases), neurofibromas (12 cases), fibrolipomas (6 cases), neurilemmomas (3 cases) and synovioma (1 case). The twenty-one malignant cases included lymphomas (6 cases), malignant teratomas (5 cases), fibrosarcomas (3 cases), interstitialomas (6 cases) and malignant mesothelioma (1 case). Complications occurred in 16.1% of patients including intra-operative bleedings (6 cases), rectal injury (6 cases) and presacral infection (3 cases). CONCLUSIONS Primary retrorectal tumors are very rare. Successful treatment of these tumors requires extensive knowledge of pelvic anatomy and expertise in pelvic surgery.

Mammotome® biopsy system for the resection of breast lesions: Clinical experience in two high‑volume teaching hospitals

Ultrasound-guided vacuum-assisted breast biopsy (VABB) is regarded as a feasible, effective, minimally invasive and safe method for the removal of benign breast lesions, without the occurrence of serious complications. The aim of this study was to evaluate the feasibility, efficacy and safety of ultrasound-guided VABB using the Mammotome® biopsy system in the treatment of breast lesions. The clinical outcomes of 3,681 patients with breast lesions were evaluated following excisions by ultrasound-guided VABB in two high-volume teaching hospitals. From January 2008 to December 2012, a total of 4,867 ultrasound-guided VABB procedures were performed in the 3,681 patients, who had a mean age of 37.8 years (range, 16–73 years). The parameters examined in this analysis included lesion size, lesion location in the inner breast, Breast Imaging Reporting and Data System (BI-RADS) ultrasound category and histopathological diagnosis. Ultrasonography follow-up was performed at 3–6 month intervals in order to assess recurrence. The size of the investigated lesions ranged between 6 and 62 mm and a histopathological diagnosis was made in 100% of cases. The results indicated that the majority of specimens (98.89%) were benign. On average, the ultrasound-guided VABB was performed in 10.3 min (range, 7.5–43 min) and the mean number of cores removed in the procedure was 8.1 (range, 3–32). A complete excision was achieved in the majority of cases (99.7%). The presence of a hematoma was the most common complication following the biopsy, and was observed in 27.5% of patients. The mean follow-up period was 25.5 months (range, 1–60 months), during which the rate of recurrence was 4.4%. The results indicated that ultrasound-guided VABB using the Mammotome biopsy system is an effective and safe procedure that is able to rapidly remove the majority of benign breast lesions using a small incision and without the occurrence of scarring or complications.

The Utility of Sentinel Lymph Node Biopsy in Papillary Thyroid Carcinoma with Occult Lymph Nodes

Background The sentinel lymph node (SLN) is defined as the first draining node from the primary lesion, and it has proven to be a good indicator of the metastatic status of regional lymph nodes in solid tumors. The aim of this study was to evaluate the clinical application of SLN biopsy (SLNB) in papillary thyroid carcinoma (PTC) with occult lymph nodes. Methods From April 2006 to October 2012, 212 consecutive PTC patients were treated with SLNB using carbon nanoparticle suspension (CNS). Then, the stained nodes defined as SLN were collected, and prophylactic central compartment neck dissection (CCND) followed by total thyroidectomy or subtotal thyroidectomy were performed. All the samples were sent for pathological examination. Results There were 78 (36.8%) SLN metastasis (SLNM)-positive cases and 134 (63.2%) SLNM-negative cases. The sensitivity, specificity, positive and negative predictive values, and false-positive and false-negative rates of SLNB were 78.8%, 100%, 100%, 84.3%, 0%, and 21.2%, respectively. The PTC patients with SLNM were more likely to be male (48.2% vs. 32.7%, p = 0.039) and exhibited multifocality (52.6% vs. 33.3%, p = 0.025) and extrathyroidal extension (56.7% vs. 33.5%, p = 0.015). A greater incidence of non-SLN metastases in the central compartment was found in patients with SLNM (41/78, 52.6%) than in those without SLNM (21/134, 15.7%; p < 0.05). However, the SLNM-negative PTC patients with non-SLN metastases were more likely to be male (37.9% vs. 9.5%, p < 0.05). Conclusions The application of SLNB using CNS is technically feasible, safe, and useful, especially for male patients with co-existing multifocality and extrathyroidal extension. However, the sensitivity of SLNB must be improved and its false-negative rate reduced before it can be a routine procedure and replace prophylactic CCND. More attention should be paid to PTC patients (especially males) without SLNM for signs of non-SLN metastases.

Syringocystadenoma papilliferum in the right lower abdomen: a case report and review of literature.

Syringocystadenoma papilliferum (SCAP) is an uncommon benign adnexal tumor of the skin. It is frequently seen in association with other benign adnexal lesions, such as nevus sebaceous, apocrine nevus, tubular apocrine adenoma, apocrine hidrocystoma, apocrine cystadenoma, and clear cell syringoma. The unusual reported locations of SCAP include the head and neck, the buttock, the vulva, the scrotum, the pinna, the eyelid, the outer ear canal, the forehead, the back, the scalp, the thigh, the nipple, the axilla, and the postoperative scar. The occurrence of SCAP in the right lower abdomen is distinctly uncommon. Herein, we report an unusual case of a 41-year-old man with SCAP occurring in the right lower abdomen that did not develop malignancy, despite a long disease course and an absence of medical treatment. The clinical and histopathologic features and the differential diagnosis of SCAP are also discussed.

Learning curve for endoscopic thyroidectomy: a single teaching hospital study.

Background Endoscopic thyroidectomy allows surgeons to remove a thyroid tumor from a remote site, while providing excellent results from a cosmetic viewpoint. Endoscopic thyroidectomy via the breast approach is a recent technique that requires a learning curve. Research on the learning curve for endoscopic thyroidectomy could be a method for investigating the surgical outcome. Methods This retrospective study investigated 100 consecutive patients who underwent endoscopic thyroidectomy performed by a single endoscopist over a period of 5 years. From January 2007 to December 2011, 100 of 355 patients scheduled for endoscopic thyroidectomy selected the breast approach. We divided the patients into four groups. Each group consisted of 25 patients: group A (cases 1–25), group B (cases 26–50), group C (cases 51–75), and group D (cases 76–100). Results The operative times for groups A, B, C, and D were 100.52 ± 25.13, 80.34 ± 20.22, 72.42 ± 15.33, and 63.35 ± 15.11 minutes, respectively (P < 0.05). Conclusion After 25 cases, we observed that endoscopic thyroidectomy via the breast approach enables a shorter mean operative time and a reduced complication rate.

Transarterial chemoembolization for patients with unresectable hepatocellular carcinoma: a retrospective study of a 5-year experience in a single institution.

BACKGROUND/AIMS Transarterial chemoembolization (TACE) is the mainstay of management for patients with unresectable hepatocellular carcinoma (HCC). The aim of this study is to evaluate the survival rates of patients with unresectable HCC following TACE performed in a single center. METHODOLOGY The authors retrospectively assessed the electronic medical records of 512 patients in whom HCC was newly diagnosed from January 2008 to December 2012 at a single tertiary medical center. Patients with decompensated hepatic function were excluded. Hepatic artery infusion chemotherapy was performed using one drug or combinations of oxaliplatin, fluorouracil and doxorubicin. The primary endpoint of the study was overall survival (OS). Survival rates were calculated using Kaplan-Meier method. RESULTS A total of 512 HCC patients (425 men and 87 women; mean age, 58.9 years; age range, 38.3-86.1 years) were treated with TACE in a single center. The overall survival rates at 1, 2, and 3 years were 62%, 43%, and 37%, respectively. The overall median survival time from the start of TACE treatment was 15 months. CONCLUSIONS TACE is an effective minimally invasive therapy option for palliative treatment of HCC patients.

Antitumor effect of FP3 in combination with cetuximab on patient-derived tumor tissue xenograft models of primary colon carcinoma and related lymphatic and hepatic metastases

FP3 is an engineered protein which contains the extracellular domain 2 of vascular endothelial growth factor (VEGF) receptor 1 (Flt-1) and the extracellular domain 3 and 4 of VEGF receptor 2 (Flk-1, KDR) fused to the Fc portion of human immunoglobulin G1. Previous studies have demonstrated its antiangiogenic effects in vitro and in vivo, and its antitumor activity in vivo. Cetuximab is a monoclonal antibody against epidermal growth factor (EGF) receptor. Combined inhibition of VEGF and EGF signaling may act additively or synergistically. In this study, patient-derived tumor tissue (PDTT) xenograft models of primary colon carcinoma and lymphatic and hepatic metastases were established for assessment of the antitumor activity of FP3 in combination with cetuximab. Xenografts were treated with FP3 and cetuximab, alone or in combination. After tumor growth was confirmed, volume and microvessel density in tumors were evaluated. Levels of VEGF, EGFR and PCNA in the tumor were examined by immunohistochemical staining, and levels of related cell signaling pathway proteins were examined by western blotting. FP3 in combination with cetuximab showed significant antitumor activity in three xenograft models (primary colon carcinoma, lymphatic metastasis and hepatic metastasis). The microvessel density in tumor tissues treated with FP3 in combination with cetuximab was lower compared to that of the control. Antitumor activity of FP3 in combination with cetuximab was significantly higher than that of each agent alone in two xenograft models (colon carcinoma lymphatic metastasis and hepatic metastasis). This study indicated that addition of FP3 to cetuximab significantly improved tumor growth inhibition in the PDTT xenograft models of colon carcinoma lymphatic and hepatic metastases. Combination anti-VEGF (FP3) and anti-EGFR (cetuximab) therapies may represent a novel therapeutic strategy for the management of metastatic colon carcinoma.

Direct binding of microRNA-21 pre-element with Regorafenib: An alternative mechanism for anti-colorectal cancer chemotherapy?

The Regorafenib is a broad-spectrum kinase inhibitor that has been approved to treat colorectal cancer (CRC). However, evidences have shown that the agent is also implicated in drug interaction with microRNA-21 (miR-21), an oncogenic miRNA which plays a key role in resisting programmed cell death in CRC cells. Here, we supposed that, instead of kinase inhibition, Regorafenib can directly bind to and then stabilize miR-21 pre-element, thus preventing RNase Dicer-meditated cleavage of the pre-element to mature miR-21. In order to verify the notion, an in silico-in vitro integrated investigation of the direct intermolecular interaction between Regorafenib and miR-21 pre-element was performed by using active pocket identification, RNA-ligand docking, molecular dynamics (MD) simulation, binding energetic analysis, and fluorescence-based assay. It was revealed that the Regorafenib can bind at the major groove-like stem region of miR-21 pre-element through three geometrically satisfactory hydrogen bonds (H-bonds) as well as a number of hydrophobic forces and π-π stacking, conferring strong specificity and high stability to the RNA-ligand complex system (Kd=0.73μM). Separate inversion mutation of two base pairs (G6C, C12G) and (A13U, U4A) that are involved in the H-bonding can considerably impair the affinity of Regorafenib to miR-21 pre-element, with Kd increase to 27 and 96μM, respectively. All these supported that Regorafenib can directly bind to miR-21 pre-element at molecular level and the binding mode can be properly modeled by using the proposed integrated strategy. This study would provide a potential, alternative mechanism for anti-colorectal cancer chemotherapy with Regorafenib.