Association of the ANTXR2 gene polymorphism and ankylosing spondylitis in Chinese Han

OBJECTIVE

Ankylosing spondylitis (AS) is an inflammatory disease of unknown origin. Both genetic and environmental factors are involved. A recent genome-wide association study (GWAS) found anthrax toxin receptor 2 (ANTXR2) to be associated with AS in Caucasians. We aimed to investigate whether the ANTXR2 polymorphism is also associated with AS in a Chinese Shandong Han population.

METHODS

From 2008 to 2009, we recruited 309 patients with AS and 384 age- and sex-matched controls of Han nationality. We selected six single nucleotide polymorphisms (SNPs) of ANTXR2 (rs4333130, rs6534708, rs6818557, rs12646132, rs12509658, and rs13140055) and genotyped them by polymerase chain reaction restriction fragment-length polymorphism (PCR-RFLP) and Taqman methods. We analysed linkage disequilibrium and constructed haplotypes.

RESULTS

Cases and controls did not differ in the frequency of ANTXR2 alleles, genotypes, or haplotypes. Thus, the six SNPs of ANTXR2 are not associated with AS in our Chinese Shandong Han population.

CONCLUSIONS

ANTXR2 might not be a susceptibility gene of AS in Chinese Han.

Modification of digital music files for use in human temporary threshold shift studies

An exposure that is reproducible across clinical/laboratory environments, and appealing to subjects, is described here. Digital music files are level-equated within and across songs such that playlists deliver an exposure that is consistent across time. Modified music is more pleasant to listen to than pure tones or shaped noise, and closely follows music exposures subjects may normally experience. Multiple therapeutics reduce noise-induced hearing loss in animals but human trial design is complicated by limited access to noise-exposed subject populations. The development of standard music exposure parameters for temporary threshold shift studies would allow comparison of protection across agents with real-world relevant stimuli in human subjects.

Nitric oxide-releasing nanoparticle combination therapy to overcome drug resistance in platinum-resistant breast cancers

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Background: The most successful cancer chemotherapy regimens usually involve the administration of multiple cytotoxic agents simultaneously. Because different chemotherapies may have different mechanisms of action; it is difficult for cancer cells to become resistant to combination therapy. Recent investigations have discovered that nitric oxide (NO) may be involved in the reversal of cisplatin (CDDP) resistance in chemotherapy. Therefore, we sought to develop a combination regimen involving a NO-releasing prodrug (NO1) and cisplatin for the treatment of breast cancer.

Methods: The prodrug NO1 was synthesized to be localized in tumor cells and to release nitric oxide over 10 hours. The antiproliferative activity of NO1 was determined in human breast cancer cell line, MDA-MB-468LN. To evaluate the effectiveness of the CDDP/NO combination regimen, platinum-resistant MDA-MB-468LN cells were treated with either cisplatin alone ([CDDP]=0.01, 0.02 or 0.03 mM) or the CDDP/NO combination ([CDDP]=0.01, 0.02 or 0.03 mM; [NO1]=0.02 mM). The cell viability was determined 48 hours post-treatment using a live/dead trypan blue exclusion assay.

Results: The toxicity to breast cancer cells was higher than JS-K, a systemic NO agent currently in preclinical development. (NO1: IC50=26µM; JS-K: IC50=42 µM). In addition, NO1 had a long sustained release of nitric oxide, approximately one fold longer than JS-K (NO1: t1/2=6 h; JS-K: t1/2=3 h). The combination treatments resulted in 6.6-, 6.9- and 7.5-fold increase in cell death compared to cisplatin treatment alone at cisplatin concentrations of 0.01, 0.02 and 0.03 mM, respectively. A subsequent study in a murine xenograft of head and neck cancer found NO-1 conjugated to nanoparticles increased survival a mean of 10 weeks compared to controls (p<0.0001).

Conclusions: Nitric oxide prodrug NO-1 and nanoparticles of it have high anticancer activity in vivo and they can reverse platinum resistance in vitro. Ongoing studies are examining the safety and efficacy of CDDP/NO combination therapy in mouse xenografts of human breast cancer.

Wld(S) protects against peripheral neuropathy and retinopathy in an experimental model of diabetes in mice

AIMS/HYPOTHESIS

We aimed to evaluate the effect of the mutant Wld(S) (slow Wallerian degeneration; also known as Wld) gene in experimental diabetes on early experimental peripheral diabetic neuropathy and diabetic retinopathy.

METHODS

The experiments were performed in four groups of mice: wild-type (WT), streptozotocin (STZ)-induced diabetic WT, C57BL/Wld(S) and STZ-induced diabetic C57BL/Wld(S). In each group, intraperitoneal glucose and insulin tolerance tests were performed; blood glucose, glycated haemoglobin and serum insulin were monitored. These mice were also subjected to the following behavioural tests: grasping test, hot-plate test and von Frey aesthesiometer test. For some animals, sciatic-tibial motor nerve conduction velocity, tail sensory nerve conduction velocity and eye pattern electroretinogram were measured. At the end of the experiments, islets were isolated to detect glucose-stimulated insulin secretion, ATP content and extent of apoptosis. The NAD/NADH ratio in islets and retinas was evaluated. Surviving retinal ganglion cells were estimated by immunohistochemistry.

RESULTS

We found that the Wld(S) gene is expressed in islets and protects beta cells against multiple low doses of STZ by increasing the NAD/NADH ratio, maintaining the ATP concentration, and reducing apoptosis. Consistently, significantly higher insulin concentrations, lower blood glucose concentrations, and better glucose tolerance were observed in Wld(S) mice compared with WT mice after STZ treatment. Furthermore, Wld(S) alleviated abnormal sensory responses, nerve conduction, retina dysfunction and reduction of surviving retinal ganglion cells in STZ-induced diabetic models.

CONCLUSIONS/INTERPRETATION

We provide the first evidence that expression of the Wld(S) gene decreases beta cell destruction and preserves islet function in STZ-induced diabetes, thus revealing a novel protective strategy for diabetic models.

Metastatic endometrial stromal sarcoma of the lung: importance of immunohistochemical staining, clinical history and imaging studies

Proper evaluation of lung nodules is a difficult issue for clinical management of patients. Discriminating metastatic endometrial stromal sarcoma (ESS) from other primary spindle cell neoplasms of the lung using histological analysis can be challenging. This is particularly true when an adequate clinical history is lacking, because ESS metastasis can be delayed by a couple of decades. To emphasize the importance of the correlation of pathological findings with clinical history and imaging studies, we investigated 11 cases of ESS (seven low grade and four high grade) metastatic to the lung. All cases presented with one to multiple unilateral or bilateral lung nodules that were detected by chest computed tomography. Primary ESS was diagnosed from hysterectomy specimens except for one by endometrial biopsy, 0.5 to 23 years prior to metastasis. Immunohistochemical studies showed that all ESS cases were moderately to strongly positive for Bcl-2 and CD10 with >50% of tumor cells stained, except for one high grade ESS that was negative for CD10. Eight (72.7%) and seven (63.6) of the 11 cases showed positive estrogen and progesterone receptors, respectively, with a majority of positive cases showing diffuse and moderate to strong staining. Strong but patchy staining for CD34 was detected in one (9.1%) case with smooth muscle differentiation. CK7 and TTF-1 were negative in all cases. Two (18.2%) cases exhibited patchy and strong positivity for caldesmon. Two (18.2%) low grade ESS cases showed moderate to strong AE1/AE3 positivity in >50% of tumor cells, one of which also showed moderate CK19 and Cam 5.2 staining in >30% of tumor cells. One should be cautious when assessing spindle cell neoplasms of the lung in women with a history of hysterectomy. Correlation of clinical history and imaging studies with histological and immunohistochemical findings is essential to diagnosis of metastatic ESS to the lung.

Experience with adrenal schwannoma in a Chinese population of six patients

OBJECTIVES

Benign adrenal schwannoma is an extremely uncommon cause of incidentaloma. This article describes our experience with the diagnosis and treatment of adrenal schwannoma in a Chinese population of 6 patients. To our knowledge, this is the largest series of this uncommon adrenal tumor treated in a single center.

METHODS

From May 1999 to May 2009, 6 patients with incidentally discovered adrenal schwannoma were operated on at a tertiary referral hospital in Eastern China. Clinical details, radiographic features, laboratory examinations, pathological findings, and follow-up data of these patients were analyzed.

RESULTS

Of the 6 patients, 4 were females (F) and 2 were males (M), with a mean age of 40.5 yr (range: 30-47, M:F=2:1). The 6 patients were managed with open unilateral adrenalectomy; 5 patients had schwannomas on the left side, and 1 on right side. Abnormal urine catecholamine was detected in 1 patient. The mean pathological size of these tumors was 4.3 ± 1.1 cm. The diagnosis of schwannoma was based on classic histological findings, and supported by immunohistochemistry of S-100, vimentin, and ABC positivity. In the follow- up of 47.5 ± 32.3 months, no recurrence and metastasis were observed.

CONCLUSIONS

Although there may be some clues for radiological diagnosis of adrenal schwannoma, preoperative misdiagnosis is not infrequent. Those tumors may occasionally have endocrine function. Histological examination is the key of diagnosis, and surgical resection is the treatment of choice once malignancy cannot be excluded by preoperative analyses.

Targeting the Akt/mTOR pathway in Brca1-deficient cancers

The breast cancer susceptibility gene 1 (Brca1) has a key role in both hereditary and sporadic mammary tumorigenesis. However, the reasons why Brca1-deficiency leads to the development of cancer are not clearly understood. Activation of Akt kinase is one of the most common molecular alterations associated with human malignancy. Increased Akt kinase activity has been reported in most breast cancers. We previously found that downregulation of Brca1 expression or mutations of the Brca1 gene activate the Akt oncogenic pathway. To further investigate the role of Brca1/Akt in tumorigenesis, we analyzed Brca1/Akt expression in human breast cancer samples and found that reduced expression of Brca1 was highly correlated with increased phosphorylation of Akt. Consistent with the clinical data, knockdown of Akt1 by short-hairpin RNA inhibited cellular proliferation of Brca1 mutant cells. Importantly, depletion of Akt1 significantly reduced tumor formation induced by Brca1-deficiency in mice. The third generation inhibitor of mammalian target of rapamycin (mTOR), Palomid 529, significantly suppressed Brca1-deficient tumor growth in mice through inhibition of both Akt and mTOR signaling. Our results indicate that activation of Akt is involved in Brca1-deficiency mediated tumorigenesis and that the mTOR pathway can be used as a novel target for treatment of Brca1-deficient cancers.