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.

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.

Giant intraosseous schwannoma of scapula: a rare case report and review of the literature.

Bony schwannoma is a rare benign tumor derived from schwann cells of nerve fibers in the bone. It accounts for less than 1% of bony benign tumor, and prone to occur in the sacrum and mandible, occurrence in scapula is very rare. Here we report a 42-year-old woman with the chief complaint of pain in the left scapula. Imaging examination showed a giant, irregular, swelling lesion with distinct border involving the left scapula, extending into the left shoulder glenoid and pressing the surrounding soft tissues. Needle biopsy showed that the tumor was composed of spindle cells with S-100 protein positive, mimicking a benign neurogenic tumor. Then a complete excision was performed by removing the tumor and the surrounding tissues including partial left shoulder glenoid. Histologically, Antoni type A areas were the predominant microscopic pattern with occasional alternation by Antoni type B areas. Immunohistochemistry found that the neoplastic cells were scatteredly positive for S-100 protein. All these features suggest a diagnosis of an intraosseous schwannoma of the left scapula. Follow-up of the patient for ten months found no recurrence or sign of other tumors following complete tumor resection without any adjuvant therapy. In conclusion, this case of giant intraosseous schwannoma of the scapula is a rare benign bony tumor, and its diagnosis combined with clinical, imaging and pre-operative needle biopsy is important to guide further therapy, and avoid overtreatment. VIRTUAL SLIDES: The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1399352761104042.

Primary central nervous system plasmablastic lymphoma presenting in human immunodeficiency virus-negative but Epstein-Barr virus-positive patient: a case report.

We report a 32-year-old Outer Mongolian man, with plasmablastic lymphoma (PBL) primarily occured in the central nervous system and diagnosed by surgical resection. This patient appeared headache and magnetic resonance imaging (MRI) showed multiple lesions in the right cerebral hemisphere including the right frontal-parietal lobe and right basal ganglia and the left cerebellum, he was diagnosed as lymphoma by stereotactic biopsy in January 2009 in local hospital, and was given radiotherapy 33 times after the biopsy. The patient was admitted to The Military General Hospital of Beijing PLA., Beijing, P.R. China on March 9th, 2011, with chief complaints of right limbs convulsioned suddenly, then fell down and lose of his consciousness, then awoke after 4 to 5 minutes, with symptoms of angulus oris numbness and the right upper limb powerless ten days ago.MRI of the brain revealed a well-defined hyperdense and enhancing mass in the left frontal-parietal lobe, the meninges are closely related, there was extensive peritumoural edema noted with pressure effects, as evident by effacement of the left lateral ventricles and a 0.5 cm shift of the midline to the right side.Surgical resection showed markedly atypical, large singly dispersed or cohesive proliferation of plasmacytoid cells with frequent abnormal mitoses and binucleation, some neoplastic cells were large with round or oval nuclei and showed coarse chromatin and smaller or unapparent nucleoli, some neoplastic cells with prominent nucleoli, apoptosis and necrosis were often presented. Immunohistochemistry staining and gene rearrangement together with other supportive investigation confirmed the diagnosis of primary central nervous system plasmablastic lymphoma. A month later, he was started on chemotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, leurocristime and prednisone) for a week. Other supportive treatment was provided for symptomatic epilepsy. The patient regained muscle strength in both upper limbs and right lower limb and the symptomatic epilepsy was controlled after two weeks. Then the patient was discharged. Follow-up data shows the patient to be alive eleven months after discharge. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1649317674697046.

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.