Design, synthesis, and anticancer evaluation of ammosamide B with pyrroloquinoline derivatives as novel BRD4 inhibitors.

Bromodomain-containing protein 4 (BRD4), which is a member of the bromodomain and extra-terminal domain (BET) family, plays an important role in the regulation of gene expression as the "reader" of epigenetic regulation. BRD4 has become a promising target to treat cancer, because the up-regulation of BRD4 expression is closely associated with the occurrence and development of various cancers. At present, several BRD4 inhibitors are in clinical trials for cancer therapy, but no BRD4 inhibitors are on the market. Here, we designed and synthesized a series of compounds bearing pyrrolo[4,3,2-de]quinolin-2(1H)-one scaffold through structural modification of natural products ammosamide B, which is a natural pyrroloquinoline derivative reported for its potential antitumor activity. All target compounds were evaluated for their BRD4 BD1 inhibition activities via the protein thermal shift assays or AlphaSceen assay. The representative compound 49 showed potent activity (IC50 = 120 nM). The co-crystal of compound 49 with BRD4 BD1 was solved to study the structure activity relationship, which showed that 49 could combine with the acetyl lysine binding site and formed a hydrogen bond with the conserved residue Asn140. The results demonstrate that compound 49 is worthy of further investigation as a promising BRD4 inhibitor.

Sanguinarine caused larval lethality and growth inhibition by suppressing energy metabolism in silkworms, Bombyx mori.

Sanguinarine (Sang) is a natural alkaloid and distributed in several plants of Papaveraceae. The antitumor, antioxidant, antimicrobial and anti-inflammatory effects of Sang were extensively reported, but its speciality and mechanism against Lepidoptera insects were still unknown. In this study, detailed toxicological parameters of Sang against silkworms, Bombyx mori (B. mori), were determined by a toxicological test. Then, a nuclear magnetic resonance-based (NMR) metabolomics method was adopted to analyze the changes in hemolymph metabolites of silkworms after feeding Sang. The growth of fourth-instar larvae was significantly ceased by the oral administration of 0.05-0.3% Sang and vast deaths appeared in 0.3% Sang group on Day 4 and Day 5. The quantitative analysis of metabolites indicated that trehalose and citrate levels in hemolymph were increased after 24 h of feeding 0.3% Sang, whereas the concentrations of pyruvate, succinate, malate and fumarate were decreased. In addition, the enzymatic determination and reverse transcription quantitative PCR (RT-qPCR) showed that the trehalase (THL) activity and the transcriptional level of one gene coding THL were uniformly weakened by 0.3% Sang. One of the important mechanisms of Sang against silkworms might be interpreted as follows. Sang impaired trehalose hydrolysis, reduced THL activity and transcription, and led to the inhibition of energy metabolism, consequent antigrowth and high lethality in larvae of B. mori. Our findings offered new insights into the insecticidal effect of Sang from the perspective of energy metabolism and provided the basis for the application of Sang in the control of Lepidoptera pests.

Excessive activated T-cell proliferation after anti-CD19 CAR T-cell therapy.

Excessive activated T-cell proliferation was observed in vivo in one patient after an anti-CD19-chimeric antigen receptor (CAR) T-cell infusion. The patient, who had chemotherapy refractory and CD19+ diffuse large B-cell lymphoma (DLBCL), received an anti-CD19 CAR T-cell infusion following conditioning chemotherapy (fludarabine/cyclophosphamide). The lymphocyte count in the peripheral blood (PB) increased to 77 × 109/L on day 13 post infusion, and the proportion of CD8+ actived T cells was 93.06% of the lymphocytes. Then, the patient suffered from fever and hypoxaemia. Significant increases in serum cytokine, lactate dehydrogenase, aspartate aminotransferase (AST), alanine transaminase (ALT), and glutamic-oxalacetic transaminase (γ-GT) levels were observed. A high-throughput sequencing analysis for T-cell receptors (TCRs) and whole-genome sequencing were used to explore the mechanisms underlying this excessive T-cell proliferation. TCR diversity was demonstrated, but no special gene mutation was found. The patient was found to be infected with the John Cunningham polyomavirus (JCV). It cannot be ruled out the bystander activation pathway induced by JCV infections related the excessive activated T-cell proliferation. Although the clinical and laboratory data do not fully explain the reason for excessive T-cell proliferation after the anti-CD19 CAR T-cell infusion, the risk of this type of toxicity should be emphasized. This study was registered at www.clinicaltrials.gov as NCT01864889.

Cu(II)-Catalyzed Ortho-C-H Nitration of Aryl Ureas By C-H Functionalization.

A novel protocol for the aromatic ortho C-H nitration of aryl ureas with Fe(NO3)3·9H2O is developed. The reaction utilizes CuCl2·2H2O as catalyst and p-TSA as additive, showing good functional group tolerance and furnishing the desired products in moderate to excellent yields.

Reconstruction of extensive thoracic wall defect using the external oblique myocutaneous flap: An analysis on 20 Chinese patients with locally advanced soft tissue sarcoma.

BACKGROUND: Soft tissue sarcomas are rare neoplasms that can occur in the thoracic wall, abdominal wall, extremities, and inguinal region. Wide local resection, with precise histological margin control, results in large skin defects that are challenging to close. Various repair procedures, such as vertical rectus abdominis flaps (VRAM), latissimus dorsi flaps, and tensor fascia lata (TFL) flaps are used to cover broad thoracic wall defects. Although the cosmetic reconstruction results of using these flaps are often excellent, each has significant drawbacks. The external oblique musculocutaneous flap is a simple and safe surgical procedure for covering thoracic wall defects. OBJECTIVE: This study aimed to retrospectively assess the safety and technique of using the external oblique musculocutaneous flap to cover large thoracic wall defects after radical excision of locally advanced sarcomas in 20 patients at a single institution. METHOD: From January 2006 to December 2016, 20 Chinese patients with large advanced sarcomas on their trunks received wide local resection, with precise histological negative margins. The external oblique musculocutaneous flap, mobilized from the ipsilateral abdominal wall, was harvested to cover broad thoracic wall defects. RESULTS: Among the 20 sarcoma patients (12 females and 8 males, ranging in age from 25 to 73 years), there were five patients with primary tumors and 15 patients with recurrent tumors. The median tumor diameter was approximately 15.3 cm. After excising the lesion, the median time to cover the defect with the external oblique myocutaneous flap was 66 min. The average blood loss when harvesting the flap was approximately 48 mL. For the 20 patients in our cohort, the external oblique flap achieved closure of defects measuring an average area of 256 cm2 . No other flaps or reconstruction techniques were used to cover the large defects in this study. There were no deaths directly related to the flap reconstruction procedures. CONCLUSION: The external oblique musculocutaneous flap was a safe and reliable method of covering broad thoracic wall defects after radical tumor excision.

[Expression of hypoxia-inducible factor 1α in osteosarcoma and its value in predicting chemosensitivity].

OBJECTIVE: To investigate the prognostic values of HIF-1α, APE1, VEGF, and COX-2 protein expressions and their predictive value of tumor necrosis rate and prognosis in osteosarcoma, as well as their interrelationships. METHODS: Formalin-fixed paraffin-embedded tissue samples were obtained from patients with osteosarcoma. Immunohistochemical assay was performed in pre-chemotherapy samples to determine the HIF-1α, VEGF, APE1, and COX-2 protein expression levels. Hematoxylin-eosin staining was used in post-operative samples to determine the tumor necrosis rate. Univariate and multivariate analyses were used to assess the impact of protein expression on prognosis. RESULTS: Tumor tissues were obtained from 49 patients. Their median follow up was 29 months. HIF-1α was significantly correlated to every protein we tested: VEGF (P = 0.032), APE1 (P < 0.001), and COX-2 (P < 0.001). HIF-1α protein expression had a significant impact on disease free survival (P = 0.006). Expression of HIF-1α had a sensitivity of 64.7% and a specificity of 71.9% for poor pathological response (< 90% of tumor necrosis) versus good pathological response to chemotherapy (≥ 90% necrosis). CONCLUSION: Expression of HIF-1α is a predictor of tumor response to neoadjuvant chemotherapy and outcome in osteosarcoma and is correlated with VEGF, APE1, and COX-2 expression.

Fibroblast growth factor receptor 4 regulates proliferation and antiapoptosis during gastric cancer progression.

BACKGROUND: Fibroblast growth factor receptor 4 (FGFR4) belongs to the tyrosine kinase receptor family. Little is known about the effect of FGFR4 on gastric cancer (GC). Therefore, the objective of the current study was to elucidate the role of FGFR4 in the tumorigenesis and progression of GC. METHODS: FGFR4 and some common prognosis markers, including p53, neu, and proliferating cell nuclear antigen (PCNA), were detected in 71 tissue samples from patients with GC using immunohistochemical analysis. In addition, a series of functional assays were carried out using small interfering RNA (siRNA) and included proliferation assays, clone assays, and apoptosis detection. RESULTS: Cytoplasmic FGFR4 expression in GC tissues was negative (7% of samples), low (14.1% of samples), intermediate (40.8%), and high (38% of samples). FGFR4 expression was associated with lymph node status and with PCNA and neu expression (P < .05). The 5-year relative survival rate was 61.5% in patients who had GC with low FGFR4 expression but was only 42% in patients who had high FGFR4 expression (P = .058). A subgroup analysis of the patients who had high FGFR4 expression revealed that those with stage III and IV disease had a worse prognosis (P = .044). Moreover, knockdown of FGFR4 expression led to decreased proliferation and an increased rate of apoptosis in the MKN45 and SGC7901 GC cell lines (P < .05). Western blot analysis demonstrated that the expression of caspase 3 increased, whereas the expression of extra-large B-cell lymphoma (Bcl-xL) decreased in MKN45 and SGC7901 cells after FGFR4-siRNA transfection. CONCLUSIONS: FGFR4 expression in GC tissue was extremely high. The current results indicated that FGFR4 may contribute to the progression of GC by regulating proliferation and antiapoptosis, indicating that FGFR4 may be a potential, novel drug target against GC.

Prognostic analysis of familial gastric cancer in Chinese population.

BACKGROUND: The aim of this study was firstly to elucidate the prognosis of familial gastric cancer (FGC) in Chinese population. METHODS: A total of 162 patients were recruited, including 81 patients with FGC and 81 patients with sporadic gastric cancer (SGC), who underwent gastrectomy between 1996 and 2007. Paraffin-embedded tumor specimens were obtained from tissue bank of Cancer Hospital, Fudan University. The expression of epidermal growth factor receptor (EGFR), P53, C-myc, and proliferating cell nuclear antigen (PCNA) were detected by immunohistochemical method. RESULTS: There were significant differences in tumor size, vessel invasion, EGFR, and P53 expression between FGC and SGC patients. The 5-year survival rates were 48% and 57% in FGC and SGC patients, respectively (P = 0.033). Subgroup analysis showed that the 5-year survival rates were worse in FGC patients with nerve invasion, high PCNA expression, negative expression of EGFR, and positive expression of P53 than those in SGC group. Multivariate analysis showed that AJCC stage, tumor size, and nerve invasion were independent prognostic factors in all patients. Furthermore, AJCC stage and P53 expression dramatically affected the prognosis of FGC patients. CONCLUSIONS: The prognosis of FGC patients might be worse than those of SGC patients. AJCC stage and P53 expression are independent prognostic factors in FGC patients.

[Differential expression of immunohistochemical markers between cardiac carcinoma and carcinoma in antrum of stomach and correlation thereof with clinicopathological factors].

OBJECTIVE: To study the differences in expression of several common immunohistochemical markers: epidermal growth factor receptor (EGFR), topoisomerase II (TOPOII), glutathione S-transferase pi (GST-pi), proliferation cell nuclear antigen ( PCNA), Her-2/Neu, P27, P21, and P53, between cardiac carcinoma and carcinoma in antrum of stomach and the correlation thereof with clinicopathological factors. METHODS: 211 paraffin-embedded tissue samples of gastric cancer were randomly chosen from the patients of cardium and stomach operated in 2005, including 110 cases of cardiac carcinoma and 101 cases of carcinoma in antrum of stomach. Immunohistochemical Envision two step method was used to detect the expression of the above mentioned markers. RESULTS: Compared to the cardiac carcinoma, the carcinoma in antrum of stomach showed higher rate of clinicopathological staging was significantly higher, degree of differentiation lower, invasion deeper, and degree of lymph node metastasis higher (all P < 0.05). The expression rates of P21, Her-2/Neu, and GST-pi of the cardiac carcinoma group were 80.0% (88/110), 30.9% (34/110), and 92.7% (76/82) respectively, all significantly higher than those of the carcinoma in antrum of stomach group [67.0% (65/97), 16.7% (16/96), and 74.5% (41/55) respectively, P = 0.034, 0.017, and 0.003 respectively]. In the cardiac carcinoma, P21 expression was positively correlated with the expression of P27 and EGFR, the P27 expression was positively correlated with the expression of EGFR and TOPOII, and the GST-pi expression was positively correlated with the TOPOII expression (r = 0.255, P = 0.021). In the antrum of stomach carcinoma, GST-pi expression was positively correlated with the expression of EGFR, TOPOII, and Her-2/Neu, however, it was negatively correlated with the expression of PCNA, and the P27 expression was positively correlated with the P53 expression (r = 0.275, P = 0.042). CONCLUSION: Different molecular mechanisms may lead to the tumorigenesis and development of stomach carcinoma at different sites.

[Research progress on the relationship between Porphyromonas gingivalis and the malignancy of the digestive system and possible pathogenetic mechanism].

The malignant tumors including oral cancer, colorectal cancer, pancreatic cancer, and esophageal cancer, of the digestive system are a common high-fatal malignancy. Porphyromonas gingivalis, as the most important pathogen of periodontal disease, has been gradually proved that its invasiveness occurs not only in the mouth but also in other parts of the digestive system. Moreover, the relevant pathogenic mechanism is increasingly attracting the reseachers' attention. In this study, the role and possible pathogenesis of Porphyromonas gingivalis in the digestive system are described in a systematic and comprehensive way.

Metabolism of Reactive Oxygen Species in Osteosarcoma and Potential Treatment Applications.

BACKGROUND: The present study was designed to explore the underlying role of hypoxia-inducible factor 1α (HIF-1α) in reactive oxygen species (ROS) formation and apoptosis in osteosarcoma (OS) cells induced by hypoxia. METHODS: In OS cells, ROS accumulated and apoptosis increased within 24 h after exposure to low HIF-1α expression levels. A co-expression analysis showed that HIF was positively correlated with Forkhead box class O1 (FoxO1) expression and negatively correlated with CYP-related genes from the National Center for Biotechnology Information's Gene Expression Omnibus (NCBI GEO) datasets. Hypoxia also considerably increased HIF-1α and FoxO1 expression. Moreover, the promoter region of FoxO1 was directly regulated by HIF-1α. We inhibited HIF-1α via siRNA and found that the ROS accumulation and apoptosis induced by hypoxia in OS cells decreased. In this study, a murine xenograft model of BALB-c nude mice was adopted to test tumour growth and measure the efficacy of 2-ME + As2O3 treatment. RESULTS: Ad interim knockdown of HIF-1α also inhibited manganese-dependent superoxide dismutase (MnSOD), catalase and sestrin 3 (Sesn3) expression in OS cells. Furthermore, hypoxia-induced ROS formation and apoptosis in OS cells were associated with CYP450 protein interference and were ablated by HIF-1α silencing via siRNA. CONCLUSIONS: Our data reveal that HIF-1α inhibits ROS accumulation by directly regulating FoxO1 in OS cells, which induces MnSOD, catalase and Sesn3 interference, thus resulting in anti-oxidation effects. The combination of an HIF-1α inhibitor (2-mercaptoethanol,2-ME) and ROS inducer (arsenous oxide, As2O3) can prohibit proliferation and migration and promote apoptosis in MG63 cells in vitro while inhibiting tumour growth in vivo.

Autologous T Cells Expressing CD30 Chimeric Antigen Receptors for Relapsed or Refractory Hodgkin Lymphoma: An Open-Label Phase I Trial.

Purpose: Relapsed or refractory Hodgkin lymphoma is a challenge for medical oncologists because of poor overall survival. We aimed to assess the feasibility, safety, and efficacy of CD30-targeting CAR T cells in patients with progressive relapsed or refractory Hodgkin lymphoma.Experimental Design: Patients with relapsed or refractory Hodgkin lymphoma received a conditioning chemotherapy followed by the CART-30 cell infusion. The level of CAR transgenes in peripheral blood and biopsied tumor tissues was measured periodically according to an assigned protocol by quantitative PCR (qPCR).Results: Eighteen patients were enrolled; most of whom had a heavy treatment history or multiple tumor lesions and received a mean of 1.56 × 107 CAR-positive T cell per kg (SD, 0.25; range, 1.1-2.1) in total during infusion. CART-30 cell infusion was tolerated, with grade ≥3 toxicities occurring only in two of 18 patients. Of 18 patients, seven achieved partial remission and six achieved stable disease. An inconsistent response of lymphoma was observed: lymph nodes presented a better response than extranodal lesions and the response of lung lesions seemed to be relatively poor. Lymphocyte recovery accompanied by an increase of circulating CAR T cells (peaking between 3 and 9 days after infusion) is a probable indictor of clinical response. Analysis of biopsied tissues by qPCR and immunohistochemistry revealed the trafficking of CAR T cells into the targeted sites and reduction of the expression of CD30 in tumors.Conclusions: CART-30 cell therapy was safe, feasible, and efficient in relapsed or refractory lymphoma and guarantees a large-scale patient recruitment. Clin Cancer Res; 23(5); 1156-66. ©2016 AACR.

Treatment of CD20-directed Chimeric Antigen Receptor-modified T cells in patients with relapsed or refractory B-cell non-Hodgkin lymphoma: an early phase IIa trial report.

Patients with relapsed or refractory non-Hodgkin lymphoma have a dismal prognosis. Chimeric Antigen Receptor (CAR)-modified T cells (CART cells) that targeted CD20 were effective in a phase I clinical trial for patients with advanced B-cell lymphomas. We performed a phase IIa trial to further assess the safety and efficacy of administering autologous anti-CD20 CART (CART-20) cells to patients with refractory or relapsed CD20+ B-cell lymphoma. Eleven patients were enrolled, and seven patients underwent cytoreductive chemotherapy to debulk the tumors and deplete the lymphocytes before receiving T-cell infusions. The overall objective response rate was 9 of 11 (81.8%), with 6 complete remissions (CRs) and 3 partial remissions; no severe toxicity was observed. The median progression-free survival lasted for >6 months, and 1 patient had a 27-month continuous CR. A significant inverse correlation between the levels of the CAR gene and disease recurrence or progression was observed. Clinically, the lesions in special sites, specifically the spleen and testicle, were refractory to CART-20 treatment. Collectively, these results together with our data from phase I strongly demonstrated the feasibility and efficacy of CART-20 treatment in lymphomas and suggest large-scale patient recruitment in a future study. This study was registered at www.clinicaltrials.org as NCT01735604.

Prognostic factors influencing event-free survival and treatments in desmoid-type fibromatosis: analysis from a large institution.

BACKGROUND: Prognostic factors and optimal management of desmoid tumors have been discussed for decades. The authors present the results of a large series of patients with desmoid tumors treated at a single institution to investigate the prognostic factors influencing event-free survival (EFS) and suitable treatments for these rare tumors. METHODS: Two hundred fourteen patients with desmoid tumors admitted to the surgical department were included, of whom 20 were recommended for a policy of watchful waiting. The following clinical parameters were studied: admission status, age, sex, tumor site, tumor size, margin status, and therapeutic strategy. Univariate and multivariate analysis were performed for EFS. RESULTS: Forty-two patients had local recurrence. One patient died of intra-abdominal disease. The 5-year and 10-year EFS rates were 78.8% and 77.9%, respectively. In univariate analysis, admission status, tumor site, tumor size, and group (R0 vs R1 and R0 vs R2) had significant impacts on EFS. EFS discrepancy was not significant between R1 and R2 or biopsy groups. In multivariate analysis, tumor size and admission status had independent value. The median delay to progression for patients undergoing watchful waiting was comparable with that for the surgical group. CONCLUSIONS: This study demonstrates that tumor size and a history of recurrence are independent predictors of EFS. Surgery is warranted if it can be R0 and function sparing. Nonsurgical modalities or a policy of watchful waiting may be a better choice for unresectable disease.

Sox17 regulates proliferation and cell cycle during gastric cancer progression.

Sox17, a transcription factor, was considered as an antagonist to inhibit canonical Wnt/ß-catenin signaling in several malignant tumors. Extremely little is known about Sox17 in gastric cancer. Therefore, the aim of this study was to elucidate the vital role of Sox17 in the tumorigenesis and progression of gastric cancer. Real time PCR was used to detect the expression of Sox17 in gastric cancer tissue. Furthermore, a series of function assays, utilizing small interfering RNA (siRNA)-mediated knockdown of Sox17 expression in MKN45 gastric cancer cells, have been performed in this study, including proliferation assay, clonogenic assay, cell-cycle evaluation, apoptosis detection as well as western blot assay. Sox17 expression were low in gastric cancer tissues as compared to normal tissue (P=0.013). Knockdown of Sox17 by Sox17-siRNA markedly enhanced the proliferation ability of MKN45 cells when compared with negative siRNA-infected cells and mock group (P<0.05). Down-regulation of Sox17 contributed to increasing cloning efficiency and activating cell cycle of MKN45 cells (P<0.05). However, there was no significantly statistical difference in terms of apoptosis rate between Sox17-siRNA group and Negative or mock group. Western blot assay revealed that the expression of CyclinD1 observably increased while p27(Kip1) expression remarkably decreased in MKN45 cells with Sox17-siRNA transfection. Furthermore, apoptosis-related molecules, Caspase3 and Bcl-xl, have no dramatically discrepant expression when knockdown of Sox17 in MKN45 cells. Sox17 prominently contributes to gastric cancer progression through regulating proliferation and cell cycle, indicating a novel diagnosis and prognosis biomarker as well as a potential therapeutic target in gastric cancer.

[Oncogenic signaling mechanisms in imatinib-resistant gastrointestinal stromal tumor].

OBJECTIVE: To characterize oncogenic KIT signaling mechanisms in gastrointestinal stromal tumor(GIST), and to determine which signaling pathway might be of potential relevance to imatinib acquired resistance. METHODS: The mutations of KIT and PDGFRa gene were evaluated and KIT downstream signaling profiles were evaluated in 8 specimen from 5 GIST patients who were evaluated treated between 2003 and 2008 in our hospital. Biochemical inhibition of the expression of related proteins in Ras/Raf/MAPK and PI3-K/AKT pathways, such as KIT, mitogen-activated protein kinase(MAPK),mammalian target of rapamycin(MTOR), AKT, Proliferating cell nuclear antigen (PCNA) and BCL-2, were determined by Western blotting for protein activation. RESULTS: Three cases who showed response to imatinib carried primary mutations in KIT gene, with 2 cases possessing mutation in exon 11, 1 case in exon 13. One case with imatinib-resistance developed KIT secondary mutation, but all the cases had no PDGFRa mutation. p-KIT and p-AKT expressions were higher in the samples of imatinib-resistant GIST than those of imatinib-responsive GIST. Total KIT, MAPK, p-MAPK, p-MTOR expressions were strong and comparable in all varied GISTs, which had no significant difference between imatinib-resistant and imatinib-responsive samples. PCNA and BCL-2 expression varied in samples of different therapy cycles and different location. CONCLUSIONS: Ras/Raf/MAPK and PI3-K/AKT/MTOR pathways are essential to GIST pathogenesis. The KIT secondary mutation and PI3-K/AKT/MTOR pathway are particularly relevant for therapeutic targeting in imatinib-resistant GIST.

Molecular mechanisms of secondary imatinib resistance in patients with gastrointestinal stromal tumors.

AIMS AND BACKGROUND: Most gastrointestinal stromal tumor (GIST) patients respond to KIT inhibition therapy of imatinib, but eventually become resistant with a median time to progression of 2 years. The mechanism of acquired resistance to imatinib and oncogenic KIT signal transduction in GISTs has not been well defined. We sought to investigate the spectrum of molecular and genomic changes in imatinib-resistant GIST patients. METHODS: KIT and PDGFRA mutations were evaluated in 48 samples obtained from 32 GIST patients who underwent surgery after imatinib treatment. KIT downstream signaling profiles were also investigated in eight specimens of five patients who were clinically responsive or resistant to imatinib therapy. Biochemical inhibition of KIT, mitogen-activated protein kinase (MAPK), mammalian target of rapamycin (MTOR), AKT, proliferating cell nuclear antigen (PCNA) and BCL-2 were determined by western blotting for protein activation. RESULTS: In all 32 GIST patients, activating mutations in the KIT gene were seen in 26 (81.3%) patients, PDGFRA gene mutations were seen in 2 (6.2%) patients and no primary mutations were found in 4 (12.5%) patients. Secondary KIT mutations were identified in 11/14 (78.6%) imatinib-acquired-resistance patients, with nine patients in KIT gene exon17, and the other two in exon 13. The expressions of p-KIT, p-AKT, PCNA and BCL-2 were higher in the samples of imatinib-resistant GISTs than those of imatinib-responsive ones. P-KIT, p-AKT expressions were higher in imatinib acquired-resistance GISTs with secondary KIT mutations than imatinib-responsive ones with primary mutation. Total KIT, MAPK, p-MAPK, p-MTOR expressions were comparable in all varied GISTs. CONCLUSIONS: Novel additional mutations of KIT gene exon 13 or exon 17 indicate the likely mechanism of secondary resistance to imatinib. The PI3-K/AKT pathway might be more relevant than MEK/MAPK for therapeutic targeting in imatinib-resistant GIST patients with secondary mutation.

[Surgical treatment for patients with advanced gastrointestinal stromal tumor after targeted therapy].

OBJECTIVE: To explore the role of surgery and its long-term outcome in patients with advanced gastrointestinal stromal tumor(GIST) treated with imatinib preoperatively. METHODS: Thirteen patients receiving imatinib therapy preoperatively, were retrospectively assessed for completeness of surgical resection and for disease-free and overall survival after resection. RESULTS: Thirteen patients, including 3 patients with locally advanced primary GIST and 10 patients with recurrent or metastatic GIST, underwent surgery after preoperative treatment with imatinib. Complete resections were accomplished in 4 of the 5 responsive disease(RD) patients, and in 1 of the 8 progression disease(PD) patients (38.5%). The progression-free survival(PFS) time for patients with RD and PD were 24.8 months and 2.8 months respectively. The difference of PFS between patients with RD and those with PD was significant(P<0.01). Median overall survival(OS) was not reached in both patients with RD and PD. The difference of OS between patients with RD and those with PD was not significant(P>0.05). CONCLUSION: Surgical intervention following imatinib is feasible and can be considered for patients with advanced GIST responsive to imatinib.