Establishment and characterization of human metastatic hepatocellular carcinoma cell line

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with a poor prognosis. Recently, we established a HCC cell line from a metastatic HCC tumor. GTG banding analysis was performed and the karyotype showed that this metastatic HCC cell line is a hypertriploid (71-78 chromosomes) with a large marker chromosome containing a long homogeneously staining region (hsr). Comparative genomic hybridization was applied to characterize the chromosomal alterations in this metastatic HCC cell line. The results showed that the hsr was composed of amplified DNA sequences from 11q13. Further characterization of the hsr may lead to the isolation of the putative amplified oncogene at 11q13.     

Glial cell line-derived neurotrophic factor family receptors are abnormally expressed in aganglionic bowel of a subpopulation of patients with Hirschsprung's disease

Hirschsprung's disease (HSCR), a congenital disease, is characterized by the absence of ganglion cells in the ganglion plexuses of the caudal most gut. In the aganglionic colon, the plexus remnants are replaced by aggregates of glial cells and hypertrophied nerve fibers. Signaling of glial cell line-derived neurotrophic factor (GDNF)-GFRAs-receptor tyrosine kinase (RET) is crucial for the development and maintenance of ganglion cells. Mutations of genes such as GDNF and RET lead to the perturbation of this signaling pathway, which causes HSCR. To understand the role of GFRAs in ganglion cells and the pathogenesis of HSCR, we intended to determine the specific cell lineages in the enteric nervous system that normally express GFRAs but are affected in HSCR. We studied colon biopsy specimens from 13 patients with HSCR (aged 1 day to 38 months) and 6 age-matched patients without HSCR as normal controls. RT-PCR, in situ hybridization, and immunohistochemistry were performed to examine the expression and cellular distributions of GFRAs in resected bowel segments of normal infants and those with HSCR. In normal infants and normoganglionic colon of patients with HSCR, the expression of GFRA1 was restricted to the glial cells and neurones of the ganglion plexuses. GFRAs expression was found to be markedly reduced in the aganglionic colons of 3 infants with HSCR but was unaffected in the aganglionic colons of 10 other infants with HSCR. Residual GFRA expression was restricted to enteric glial cells in the plexus remnants of the aganglionic colons. Hypertrophied nerve fibers were not found to express GFRA1. We provide the first evidence that abnormal expression of GFRAs in the enteric nervous system may be involved in the pathogenesis of HSCR in a subpopulation of patients.     

Diffusion-tensor imaging for the detection and quantification of treatment-induced white matter injury in children with medulloblastoma: a pilot study

BACKGROUND AND PURPOSE: Treatment-induced white matter (WM) injury in medulloblastoma survivors, as manifested by deterioration of cognitive function, is prevalent. However, no reliable imaging method exists for early detection and quantification. Our goal was to determine whether anisotropy of WM is reduced in medulloblastoma survivors and whether fractional anisotropy (FA) can be used as an index for evaluation of treatment-induced WM injury. METHODS: We evaluated nine medulloblastoma survivors treated with surgery, cranial irradiation, and chemotherapy by use of diffusion-tensor (DT) imaging and compared FA findings in selected WM sites (cerebellar hemispheres, pons, medulla oblongata, frontal periventricular WM, parietal periventricular WM, and corona radiata) with those of healthy age-matched control subjects. FA maps were compared with conventional T2-weighted images. FA was also compared with age at treatment, time interval since treatment, and deterioration of school performance. The two-tailed paired t test was used to determine statistical significance (P <.05). RESULTS: Significant reduction of FA (P <.05) was seen in all anatomic sites in the patient group compared with FA in control subjects, except in the frontal periventricular WM, even in areas with normal appearance on T2-weighted images. FA reduction ranged from 12.4-19% (mean, 16.5%). Compared with control subjects, posterior fossa and supratentorial WM FA in patients were reduced by 14.6% (SD 1.9%) and 18.4% (SD 0.55%), respectively (P =.029). Reduction of supratentorial WM FA correlated with younger age at treatment (< 5 years), longer interval since treatment (> 5 years), and deterioration of school performance. CONCLUSION: DT imaging and use of the index FA is potentially useful for early detection and monitoring of treatment-induced WM injury in children with medulloblastoma.     

Improvement in treatment results and long-term survival of patients with esophageal cancer: impact of chemoradiation and change in treatment strategy

OBJECTIVE: To identify prognostic factors and reasons for improved survival over time in patients with esophageal cancer. SUMMARY BACKGROUND DATA: Management strategies for esophageal cancer have evolved with time. The impact of chemoradiation in the overall treatment results has not been adequately studied. METHODS: From 1990 to 2000, 399 (62.4%) of 639 patients with intrathoracic squamous cancers underwent resection. Two study periods were analyzed: period I (01/1990-06/1995), and period II (07/1995-12/2000); during period II, chemoradiation was introduced. Prognostic factors were identified by multivariate analysis and the 2 periods compared. RESULTS: Hospital mortality rate after resection decreased from 7.8% to 1.2%, P = 0.002. Five favorable prognostic factors were identified: female gender (female vs. male, HR = 0.66), infracarinal tumor location (infra vs. supra-carinal, HR = 0.63), low pTNM stage (III/IV vs. 0/I/II/T0N1, HR = 1.76), pM0 stage (M1a/b vs. M0, HR = 1.56), and R0 category (R1/2 vs. R0, HR = 2.49). Median survival was 15.8 and 25.6 months in periods I and II, respectively, P = 0.02. More R0 resections were evident in period II, being possible in 63% (period I) and 79% (period II) of patients, P = 0.001. This was attributed to tumor downstaging by chemoradiation and more stringent patient selection for resection in period II. Performing less R1/2 resections in period II coincided with using primary chemoradiation in treating advanced tumors. In patients treated without resection, survival also improved from 3 (period I) to 5.8 months (period II), P < 0.01. CONCLUSIONS: Survival has improved; chemoradiation enabled better patient selection for curative resections and also resulted in more R0 resections by tumor downstaging. This treatment strategy led to overall better outcome for the whole patient cohort, even in those treated by nonsurgical means.     

Linear accelerator-based stereotactic radiosurgery for limited,locally persistent,and recurrent nasopharyngeal carcinoma: efficacy and complications

PURPOSE: To evaluate the efficacy and complication of linear accelerator-based stereotactic radiosurgery (SRS) when used as salvage treatment for early-stage persistent and recurrent nasopharyngeal carcinoma (NPC) after primary radiotherapy (RT). MATERIALS AND METHODS: Between March 1998 and June 2001, 18 patients (15 men and 3 women; median age 46 years, range 32-84) with locally persistent or recurrent NPC confined to the nasopharynx (rT1) or with limited extension to the nasal fossa or parapharyngeal space (rT2) were treated by SRS. Thirteen patients had rT1 disease and 5 had rT2 disease. Most patients had disease not amenable to surgery or brachytherapy. All patients had undergone previous radical RT. Persistent disease was defined as tumor relapse within 4 months of completion of primary RT, and recurrence as tumor relapse beyond 4 months. Seven patients were treated for persistent disease, eight for a first recurrence, and three for a second recurrence. SRS was performed using multiple noncoplanar arcs of photons delivered to the target volume, which was defined by axial CT at a 3 mm thickness, supplemented by MRI in selected patients (67%). The median target volume was 5.3 cm(3) (range 2.2-16.9). The median SRS dose was 12.5 Gy (range 11-14) delivered to the 80% isodose line. All patients underwent serial nasopharyngoscopy and imaging after SRS. The median follow-up was 26 months (range 11-48). RESULTS: After SRS, 16 (89%) of 18 patients had complete regression of tumor as assessed by nasopharyngoscopy and biopsy. Four patients with an initial complete response to SRS subsequently developed local relapse again, with one recurrence developing outside the target volume 8 months after SRS and three within the target volume at 6-26 months after SRS. Two patients with local disease controlled by SRS developed relapse in other sites (neck node and liver metastases). The actuarial 2-year local control rate after SRS was 72%. Patients treated for persistent disease had a better local control rate (100%; 7 of 7) than those treated for recurrent disease (46%; 5 of 11). Patients with rT1 disease also had a better outcome after SRS compared with those with rT2 disease, with a control rate of 77% (10 of 13) for rT1 disease and 40% (2 of 5) for rT2 disease. Treatments were well tolerated, with no acute side effects. One patient had radiologic evidence of temporal lobe necrosis, although the right temporal lobe had already received a high dose during prior RT. That patient also developed additional local recurrence and liver metastases and died. The actuarial 2-year survival rate was 86%. CONCLUSIONS: Our preliminary results indicate that SRS is an effective treatment modality for persistent and recurrent early-stage NPC, with early control rates comparable to other salvage treatments such as brachytherapy and nasopharyngectomy. A modest SRS dose at 12.5 Gy also appears to be effective and is associated with minimal morbidities. More clinical experience and longer follow-up are needed to validate our results and to address fully the role of SRS in salvaging local failures of NPC.     

First X-ray cocrystal structure of a bacterial FabH condensing enzyme and a small molecule inhibitor achieved using rational design and homology modeling

The first cocrystal structure of a bacterial FabH condensing enzyme and a small molecule inhibitor is reported. The inhibitor was obtained by rational modification of a high throughput screening lead with the aid of a S. pneumoniae FabH homology model. This homology model was used to design analogues that would have both high affinity for the enzyme and appropriate aqueous solubility to facilitate cocrystallization studies.     

A phase II study of capecitabine in patients with recurrent and metastatic nasopharyngeal carcinoma pretreated with platinum-based chemotherapy

To evaluate the efficacy and toxicity of capecitabine as a salvage chemotherapy regimen in Chinese patients with recurrent or metastatic nasopharyngeal carcinoma (NPC) previously treated with platinum-based chemotherapy, 17 patients with recurrent or metastatic NPC previously treated with platinum-based chemotherapy as adjuvant or palliative treatments received oral capecitabine at a dose of 1.25 G/m(2) twice daily in 3-week cycles consisting of 2 weeks of treatment followed by rest period of 1 week. Seven patients had local recurrence, seven had distant metastases, one had loco-regional recurrence, and two had both local/regional recurrence and distant metastases. Patients received a median number of three cycles of capecitabine (range: 1-6). The median follow-up was 7.5 months (range: 3-25.3). All patients were included in the efficacy and adverse events analysis. Three patients (17.6%) achieved partial response and one patient (5.9%) achieved complete response, with an overall response rate of 23.5% (95% confidence interval, 7-50%). The duration of response's were 4.2, 5, 6+, and 23.1+ months. Nine patients (52.9%) had stable disease whereas four (23.5%) had progressive disease. The median time to progression was 4.9 months. The median survival was 7.6 months. Five patients are still alive with an estimated 1-year survival rate of 35%. Treatment-related adverse events were generally mild except hand-foot syndrome which occurred in 58.8% of patients. Capecitabine is an effective salvage regimen in patients with recurrent and metastatic NPC. Capecitabine as a single agent or in combination with other chemotherapeutic agents or treatment modalities should be further studied in NPC.     

Analytic power calculation for QTL linkage analysis of small pedigrees

Power calculation for QTL linkage analysis can be performed via simple algebraic formulas for small pedigrees, but requires intensive computation for large pedigrees, in order to evaluate the expectation of the test statistic over all possible inheritance vectors at the test position. In this report, we show that the non-centrality parameter for an arbitrary pedigree can be approximated by the sum of the variances of the correlations between all pairs of relatives, each variance being weighted by a factor that is determined by the mean correlation of the pair. We show that this approximation is sufficiently accurate for practical purposes in small to moderately large pedigrees, and that large sibships are more efficient than other family structures under a range of genetic models.