Screening for AIP gene mutations in a Han Chinese pituitary adenoma cohort followed by LOH analysis.

OBJECTIVE: The aryl hydrocarbon receptor interacting protein gene (AIP) is associated with pituitary adenoma (PA). AIP has not been sequenced in East Asian PA populations, so we performed this study in a Han Chinese cohort. DESIGN: Our study included six familial PA pedigrees comprising 16 patients and 27 unaffected relatives, as well as 216 sporadic PA (SPA) patients and 100 unrelated healthy controls. METHODS: AIP sequencing was carried out on genomic DNA isolated from blood samples. Multiplex ligation-dependent probe amplification and microsatellite marker analyses on DNA from the paired tumor tissues were performed for loss of heterozygosity analysis. RESULTS: We identified three common and four rare single nucleotide polymorphisms (SNPs), one intron insertion, one novel synonymous variant, four novel missense variants, and a reported nonsense mutation in three familial isolated PA (FIPA) cases from the same family. Large genetic deletions were not observed in the germline but were seen in the sporadic tumor DNA from three missense variant carriers. The prevalence of AIP pathogenic variants in PA patients here was low (3.88%), but was higher in somatotropinoma patients (9.30%), especially in young adults (≤30 years) and pediatric (≥18 years) paients (17.24% and 25.00% respectively). All AIP variant patients suffered from macroadenomas. However, the AIP mutation rate in FIPA families was low in this cohort (16.67%, 1/6 families). CONCLUSION: AIP gene mutation may not be frequent in FIPA or SPA from the Han Chinese population. AIP sequencing and long-term follow-up investigations should be performed for young patients with large PAs and their families with PA predisposition.

A minority subpopulation of CD133(+) /EGFRvIII(+) /EGFR(-) cells acquires stemness and contributes to gefitinib resistance.

AIMS: To study the contribution of epidermal growth factor receptor variant III (EGFRvIII) to glioblastoma multiforme (GBM) stemness and gefitinib resistance. METHODS: CD133(+) and CD133(-) cells were separated from EGFRvIII(+) clinical specimens of three patients with newly diagnosed GBM. Then, RT-PCR was performed to evaluate EGFRvIII and EGFR expression in CD133(+) and CD133(-) cells. The tumorigenicity and stemness of CD133(+) cells was verified by intracranial implantation of 5 × 10(3) cells into immunodeficient NOD/SCID mice. Finally, cells were evaluated for their sensitivity to EGFR tyrosine kinase inhibition by gefitinib. RESULTS: RT-PCR results showed that the sorted CD133(+) cells expressed EGFRvIII exclusively, while the CD133(-) cells expressed both EGFRvIII and EGFR. At 6-8 weeks postimplantation, CD133(+) /EGFRvIII(+) /EGFR(-) cells formed intracranial tumors. Cell counting kit-8 results showed that the IC50 values of the three isolated EGFRvIII(+) cell lines treated with gefitinib were 14.44, 16.00, and 14.66 µM, respectively, whereas the IC50 value of an isolated EGFRvIII(-) cell line was 8.57 µM. CONCLUSIONS: EGFRvIII contributes to the stemness of cancer stem cells through coexpression with CD133 in GBMs. Furthermore, CD133(+) /EGFRvIII(+) /EGFR(-) cells have the ability to initiate tumor formation and may contribute to gefitinib resistance.

Advances in medical treatment of clinically nonfunctioning pituitary adenomas.

Clinically nonfunctioning pituitary adenomas are the most common types among pituitary adenomas. These tumors are usually diagnosed in their later stages due to the absence of clinical symptoms and detectable hormonal hypersecretion. Although these tumors are benign, they are hard to be completely removed during neurosurgery due to the massive invasion into the surrounding tissues at diagnosis. Furthermore, relapse is common. In recent years, medical treatment of pituitary adenomas has witnessed a rapid development. New medications have shown certain effectiveness in reducing the tumor size and improving the clinical symptoms.

Postacute ischemia vascular endothelial growth factor transfer by transferrin-targeted liposomes attenuates ischemic brain injury after experimental stroke in rats.

Our objective was to achieve the enhanced delivery of vascular endothelial growth factor (VEGF) to ischemically disordered brain through transferrin-coupled liposomes (Tf-PLs) via intravenous administration, and to observe the effect of Tf-VEGF-PLs on ischemic brain neuroprotection and angiogenesis. Cerebral VEGF overexpression was achieved with Tf-PLs by intravenous injection 48 hr after an acute stroke. ß-Galactosidase expression was monitored; saline was injected as a control. The success of postischemic gene transduction was confirmed by ß-galactosidase staining and by increased VEGF mRNA and protein in ischemic brain. Vascular density, neurological recovery, and ischemic area calculation were performed to evaluate the effect of Tf-VEGF-PLs. The positive expression of ß-galactosidase indirectly indicated that VEGF was successfully delivered into brain by Tf-VEGF-PLs. VEGF mRNA in the Tf-VEGF-PL group 24 hr after injection was significantly higher than in the control group (p < 0.05). Western blot analysis showed that postischemic Tf-VEGF-PLs resulted in increased VEGF protein levels compared with VEGF-PLs and saline-administered rats (p < 0.05) 48 hr after administration. At 21 days after drug injection, we observed a significant decrease in infarct volume and better neurological function in the Tf-VEGF-PL-treated group, compared with the VEGF-PL group. FITC-dextran marking showed increased vascular density in the penumbra of Tf-VEGF-PL-treated hemispheres (245,873.9, number of microvessels per field) compared with that in VEGF-PL-treated hemispheres (139,801.3) or saline-treated hemispheres (102,175.5) (p < 0.05). The remainder of the cerebral blood flow after ischemia in the Tf-VEGF-PL group was significantly more than in the control groups (0.35 vs. 0.29, 0.21; p < 0.05). We conclude that the VEGF gene can be delivered noninvasively into the brain by Tf-VEGF-PLs. Postischemic treatment with Tf-VEGF-PLs effectively promoted neuroprotection and vascular regeneration in the chronic stage of cerebral infarction.