Analysis of mutation of the c-Kit gene and PDGFRA in gastrointestinal stromal tumors.

The aim of the present study was to investigate mutation status of the c-Kit gene (KIT) and PDGFRA in patients with a gastrointestinal stromal tumor (GIST). In total, 93 patients with a GIST were included in the study, in which polymerase chain reaction amplification and gene sequencing were used to detect the sequences of exons 9, 11, 13 and 17 in KIT and exons 12 and 18 in PDGFRA. KIT mutations were detected in 64 cases (68.82%), of which exon 11 mutations were detected in 56 cases (60.22%), exon 13 mutations were detected in three cases (3.23%) and one case (1.08%) was shown to have a mutation in exon 17. The most common mutation in exon 11 was a deletion, which accounted for 55.36% (31/56) of the cases, followed by a point mutation observed in 26.79% (15/56) of the cases, while an insertion (tandem repeats) was identified in 14.29% (8/56) of the cases, and 3.57% (2/56) of the exon 11 mutations were deletions associated with a point mutation. The majority of the mutations were heterozygous, with only a few homozygous mutations. Mutational analysis revealed the mutations to be more concentrated in the classic hot zone at the 5'-end, followed by the tandem repeat frame at the 3'-end. In four cases, a mutation was detected in exon 18 of PDGFRA, of which one was associated with a mutation in KIT. The remaining three cases (10.34%, 3/29) were not associated with mutations in KIT and accounted for 37.5% (3/8) of the CD117-negative GIST cases. Therefore, the majority of the GIST cases were characterized by mutations in KIT or PDGFRA, which were directly associated with the disease. Pairs of different mutations in the same exon of KIT, or KIT mutations coupled with pairs of mutations in PDGFRA, were detected in a small number of patients. Imatinib is a small molecule tyrosine kinase inhibitor and is the first line targeted treatment for GIST, resulting in markedly improved survival rates. Thus, gene mutation genotyping may provide inspiration and guidance for imatinib-based targeted cancer therapy.

Diagnosis value of CD117 and PDGFRA, alone or in combination DOG1, as biomarkers for gastrointestinal stromal tumors.

BACKGROUND: To explore the diagnostic values of CD117 and PDGFRA protein expressions, used alone or in combination with DOG1 protein, for gastrointestinal stromal tumors (GIST). METHODS: The CD117, PDGFRA and DOG1 protein expressions in 99 GIST specimens and 25 non-GIST specimens were retrospectively determined, and the potential correlations were analyzed. RESULTS: The positive rates of CD117, PDGFRA, and DOG1 expressions were 93.94% (93/99), 53.54% (53/99), and 90.91% (90/99) in GIST group and 4.00% (1/25), 4.00% (1/25), and 12.00% (3/25) in non-GIST group (all P<0.05). The expressions of CD117, PDGFRA, and DOG1 had no significant correlation with clinicopathological parameters including gender, age, tumor diameter, tumor location, histotype, and risk degree (all P>0.05). The sensitivities of CD117, PDGFRA, DOG1, CD117 + DOG1, PDGFRA + DOG1, and CD117 + PDGFRA + DOG1 were 0.989, 0.981, 0.968, 0.960, 0.933, and 0.961 in judging GIST, respectively, and the specificities were 0.800, 0.343, 0.710, 0.840, 0.947, and 0.955, respectively. The areas under the ROC curve (AUC) in these six groups were 0.945, 0.748, 0.895, 0.895, 0.840, and 0.975, respectively. CONCLUSIONS: The populations that may benefit more from the detection of CD117, PDGFRA, and DOG1 protein expression for GIST need to be further identified. Detection of CD117 and PDGFRA protein, alone or in combination with DOG1, may increase the accuracy of GIST diagnosis.

A case of lung adenocarcinoma with a concurrent EGFR mutation and ALK rearrangement: A case report and literature review.

The echinoderm microtubule associated protein like 4­anaplastic lymphoma kinase (EML4­ALK) fusion is almost mutually exclusive to epidermal growth factor receptor (EGFR) or K­RAS mutation in non­small cell lung cancer (NSCLC), and it is extremely rare for patients to exhibit both mutations. The present study reported the case of a 71-year­old female diagnosed with adenocarcinoma, exhibiting mutations in EGFR and EML4­ALK. The present study treated this patient with EGFR­TK inhibitors, as the first line therapy, and gefitinib therapy revealed a good response until now. In addition, previously reported cases and associated literature were reviewed. The present study provided a greater understanding of the molecular biology and optimal treatment for patients with NSCLC with >1 driver mutation.

Association between EML4-ALK fusion gene and thymidylate synthase mRNA expression in non-small cell lung cancer tissues.

This study aimed to investigate the association of the mRNA expression of the echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion gene with that of thymidylate synthase (TYMS) in non-small cell lung cancer (NSCLC) tissues. Quantitative polymerase chain reaction was used to detect the expression of EML4-ALK fusion gene and TYMS mRNA in 257 cases of NSCLC. The positive rate of EML4-ALK fusion gene was 4.28% in the NSCLC tissues (11/257), and was higher in nonsmokers than in smokers (P<0.05); TYMS mRNA expression was detected in 63.42% (163/257) of cases. An association of the EML4-ALK fusion gene with TYMS expression was detected; a low expression level of TYMS mRNA was observed more frequently when the EML4-ALK fusion gene was present than when it was not detected (P<0.05). In conclusion, patients positive for the EML4-ALK fusion gene in NSCLC tissues are likely to have a low expression level of TYMS, and may benefit from the first-line chemotherapy drug pemetrexed.

Association between epidermal growth factor receptor mutations and the expression of excision repair cross-complementing protein 1 and ribonucleotide reductase subunit M1 mRNA in patients with non-small cell lung cancer.

The present study aimed to investigate the association between epidermal growth factor receptor (EGFR) gene mutations and excision repair cross-complementing protein 1 (ERCC1) and ribonucleotide reductase subunit M1 (RRM1) mRNA expression in non-small cell lung cancer (NSCLC) tissue. The quantitative polymerase chain reaction was used to detect EGFR mutations, and ERCC1 and RRM1 mRNA expression in 257 cases of NSCLC. In the NSCLC samples the EGFR mutation rate was 49.03% (126/257). The rate was higher in females and non-smoking patients (P<0.05). High expression of ERCC1 mRNA was observed in 47.47% of the samples (122/257), while a high RRM1 mRNA expression was observed in 61.87% of the samples (159/257). In comparison with patients with NSCLC without EGFR mutations, patients with EGFR mutations had significantly lower levels of ERCC1 mRNA expression (P<0.05); however, EGFR mutations and expression levels of RRM1 mRNA were not correlated in NSCLC tissues (P>0.05). In addition, ERCC1 mRNA expression was not correlated with the expression levels of RRM1 mRNA (P>0.05). In conclusion, patients with NSCLC with EGFR mutations tend to have a low expression of ERCC1 mRNA and may potentially benefit from platinum-based chemotherapy.

Oncogenic role and therapeutic target of leptin signaling in colorectal cancer.

INTRODUCTION: Obesity is characterized by high secretion of several cytokines from adipose tissue and is a recognized risk factor for many cancers. Among these cytokines, leptin mainly produced by adipose tissue and cancer cells is the most studied adipokine. Leptin is an activator of cell proliferation, an antiapoptotic molecule and inducer of cancer stem cells in many cell types, and its critical roles in obesity-related tumorigenesis are based on its oncogenic, mitogenic, pro-inflammatory and pro-angiogenic actions. AREAS COVERED: These leptin-induced signals and action are critical for their biological effects on energy balance, adiposity, endocrine systems, immunity, angiogenesis as well as oncogenesis. This review focuses on the up-to-date knowledge on the oncogenic role of leptin signaling, clinical significance and specific drug target development in colorectal cancer (CRC). Additionally, leptin-induced angiogenic ability and molecular mechanisms in CRC cells are discussed. EXPERT OPINION: Stringent binding affinity of leptin/Ob-R and overexpression of leptin/Ob-R and their targets in cancer cells make it a unique drug target for prevention and treatment of CRC, particularly in obesity colorectal patients.

Primary Burkitt's lymphoma of the thyroid without Epstein-Barr virus infection: A case report and literature review.

Primary thyroid lymphomas are rare, and the majority are B-cell lymphoma. Primary Burkitt's lymphoma (BL) of the thyroid is much less common than the other types of lymphoma. The current study presents the case of an eight-year-old male with a mass in the right lobe of the thyroid, which was detected by B-ultrasound. The patient was diagnosed with BL by immunohistochemistry, fluorescence in situ hybridization analysis of MYC (8q24) and immunoglobulin rearrangement assays. Furthermore, subsequent positron emission tomography-computed tomography scans revealed no abnormal metabolites in the left lobe of the thyroid or in other parts of the body following surgery. The patient underwent alternate R-B-NHL-BFM-90-A and R-B-NHL-BFM-90-B treatment for four cycles each following the thyroidectomy. The patient is well and remains free of disease recurrence following almost four years follow-up. The present study discusses this rare case of primary BL of the thyroid and presents a review of the literature. This case report provides evidence that the immediate diagnosis and treatment of primary Burkitt's lymphoma of the thyroid is likely to improve patient outcome.

Arsenic sulfide promotes apoptosis in retinoid acid resistant human acute promyelocytic leukemic NB4-R1 cells through downregulation of SET protein.

Tetra-arsenic tetra-sulfide (As4S4) is an arsenic compound with anti-tumor activity, especially in acute promyelocytic leukemia (APL) that are resistant to retinoic acid (RA). Although recent studies revealed that the therapeutic action of As4S4 is closely associated with the induction of cellular apoptosis, the exact molecular mechanism of action of As4S4 in RA-resistant APL remains to be clarified. In this study, we found that As4S4-induced apoptosis was accompanied by reduced mRNA and protein expression of SET gene in RA-resistant NB4-R1 cells. Moreover, RNAi knockdown of SET gene further promoted As4S4-induced apoptosis, while SET over-expression inhibited it, suggesting that As4S4 induces apoptosis through the reduction of SET protein in NB4-R1 cells. We also demonstrated that the knockdown of SET gene resulted in the upregulation of protein phosphatase 2 (PP2A) expression and the downregulation of promyelocytic leukemia and retinoic acid receptor α fusion gene (PML-RARα) expression, which were enhanced by As4S4 treatments. By contrast, over-expression of SET gene resulted in PP2A downregulation and PML-RARα upregulation, which were abolished by As4S4 pretreatment. Since PP2A is a pro-apoptotic factor and PMLRARα is an anti-apoptotic factor, our results suggest that As4S4-induced apoptosis in NB4-R1 cells is through the downregulation of SET protein expression, which in turn increases PP2A and reduces PML-RARα expressions to lead to cell apoptosis.

Production of native protein by using Synechocystis sp. PCC6803 DnaB mini-intein in Escherichia coli.

To directly express native recombinant proteins in Escherichia coli, a new expression vector pSB was constructed using Ssp DnaB mini-intein. Using the vector, native proteins could be produced with the help of C-terminal self-cleavage of the intein. In this study, we cloned hIFNalpha-4 gene into pSB and used E. coli strain Origami B (DE3) as the host. Expression experiments were carried out both in Shake flasks and a 5 L bioreactor. The results indicated hIFNalpha-4 could be expressed in the form of soluble protein with correct folding in E. coli. The maximal hIFNalpha-4 content was 21.7% of total protein, and the antiviral activity of the protein was 1.2x10(8 )IU mg(-1). Overall, good effects were achieved with this system. This intein-mediated protein expression system opens up a useful method for production of native recombinant protein in E. coli.

[Clinical significance of transrectal ultrasound in detecting of rectal cancer margin and deciding of distal surgical incisal edge].

OBJECTIVE: To study the role of transrectal ultrasound in detecting and deciding rectal cancer margin and surgical incisal edge. METHODS: 33 surgical specimens of rectal carcinoma were examined with transrectal ultrasound. Cancerous margin and surgical incisal edge were determined. The results were compared with pathological examination. p53 and K-ras gene mutation as tumor molecular markers of residue cancer cells were detected in incisal edge tissue with PCR-SSCP method. RESULTS: General accuracy for cancer infiltration depth with transrectal ultrasound was 86.6%. For mucosa and submucosa infiltration lesions, the accuracy was 72.7%. For lamina muscularis, the accuracy was 90.9%. And for adventitia and peripheral tissue infiltration of rectum, the accuracy was 88.5% and 100% respectively. No remains of cancer cells and tumor molecular markers were detected at distal incisal edges of 1.0 cm, 2.0 cm and 3.0 cm determined with transrectal ultrasound. CONCLUSIONS: Rectal cancer margine and surgical incisal edge determined with transrectal ultrasound are close to examined by pathology. Transrectal ultrasound is helpful and reliable to define incisal edge in rectal cancer surgery.

[Studies on constituents of Rosa bracteata fruits(II)].

OBJECTIVE: To find the active constituents of Rosa bracteata Wendl. to antagonize withdrawal syndrome in morphinedependent mice. METHODS: The constituents were isolated and purified by silica gel chromatography repeatedly. Their structures were made clear by chemical reactions and on the evidence of spectroscopy. RESULTS AND CONCLUSIONS: Five compounds were isolated from the fruits and four of them were determined as trimethly citrate, dimethyl 3-carboxyl-3-hydroxypentanedioate, 3-hydroxy-3-methoxycarbonyl-pentanedioic acid, calcium citrate, which were found from the Rose genus plant for the first time.