Identification of a novel tumor transforming gene GAEC1 at 7q22 which encodes a nuclear protein and is frequently amplified and overexpressed in esophageal squamous cell carcinoma

By comparative DNA fingerprinting, we identified a 357-bp DNA fragment frequently amplified in esophageal squamous cell carcinomas (ESCC). This fragment overlaps with an expressed sequence tag mapped to 7q22. Further 5' and 3'-rapid amplification of cDNA ends revealed that it is part of a novel, single-exon gene with full-length mRNA of 2052 bp and encodes a nuclear protein of 109 amino acids ( approximately 15 kDa). This gene, designated as gene amplified in esophageal cancer 1 (GAEC1), was located within a 1-2 Mb amplicon at 7q22.1 identified by high-resolution 1 Mb array-comparative genomic hybridization in 6/10 ESCC cell lines. GAEC1 was ubiquitously expressed in normal tissues including esophageal and gastrointestinal organs; with amplification and overexpression in 6/10 (60%) ESCC cell lines and 34/99 (34%) primary tumors. Overexpression of GAEC1 in 3T3 mouse fibroblasts caused foci formation and colony formation in soft agar, comparable to H-ras and injection of GAEC1-transfected 3T3 cells into athymic nude mice formed undifferentiated sarcoma in vivo, indicating that GAEC1 is a transforming oncogene. Although no significant correlation was observed between GAEC1 amplification and clinicopathological parameters and prognosis, our study demonstrated that overexpressed GAEC1 has tumorigenic potential and suggest that overexpressed GAEC1 may play an important role in ESCC pathogenesis.

Ogilvie's syndrome: a case report

OBJECTIVE

Ogilvies syndrome (OS) is a rare condition in obstetrics but occurs most commonly after caesarean section. Mortality rates from OS can be as high as 36-50% when bowel perforation or ischemia develops which highlights the early recognition of this condition. Early diagnosis is therefore essential to prevent serious morbidity and mortality.

CONCLUSION

We, therefore report a case of OS after caesarean section in which early detection by senior clinicians resulted in successful management of the condition and an excellent outcome.

Risk of intracranial hemorrhage and cerebrovascular accidents in non-small cell lung cancer brain metastasis patients

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Background: Brain metastases confer significant morbidity and a poorer survival in non-small cell lung cancer (NSCLC). Vascular endothelial growth factor-targeted antiangiogenic therapies (AAT) have demonstrated benefit for patients with metastatic NSCLC and are expected to directly inhibit the pathophysiology and morbidity of brain metastases, yet patients with brain metastases have been excluded from most clinical trials of AAT for fear of intracranial hemorrhage (ICH). This is a low suspected risk, but needs to be quantitated to plan clinical trials of AAT for NSCLC brain metastases. Methods: Data from MD Anderson Cancer Center Tumor Registry and electronic medical records from January 1998 to March 2006 was interrogated. 2143 patients with metastatic NSCLC registering from Jan 1998 to Sept 2005 were followed till March 2006. 776 patients with and 1367 patients without brain metastases were followed till death, date of ICH, or last date of study, whichever occurred first. Results: The incidence of ICH seemed to be higher in those with brain metastasis compared to those without. However, the rates of symptomatic ICH were not significantly different. All ICH patients with brain metastasis had received radiation therapy for them and were not anticoagulated. Most of the brain metastasis-associated ICH's were asymptomatic, detected during radiologic surveillance. The rates of symptomatic ICH, or cerebrovascular accidents were similar and not significantly different between the two groups. The following table depicts the rates of CVA and/or ICH in metastatic NSCLC patients. Conclusions: In metastatic NSCLC patients, the incidence of spontaneous ICH appeared to be higher in those with brain metastases compared to those without, but was very low in both groups nonetheless without a statistically significant difference. These data suggest minimal risk of clinically significant ICH for NSCLC brain metastasis patients and justifies for them clinical trials of AAT.

No significant financial relationships to disclose.

[Table: see text]

Male pattern androgenetic alopecia in an Indian context: a perspective study

BACKGROUND

Androgenetic alopecia (AGA) has received scant attention, despite it being a common entity that may result in significant psychosocial morbidity. There are some patients who do not fit into any of the proposed types. Moreover, there have been no published studies of pattern and prevalence of AGA in males in an Indian context. Hence, the present study was an attempt to classify AGA in males with the aim of producing a simple, effective and easily reproducible classification.

METHODS

In total, 150 male patients were clinically diagnosed as AGA. After obtaining informed consent from all patients, a detailed history/examination was carried out, including a hair pull test, a trichogram investigation and a biopsy. Classification of AGA was subsequently attempted across Norwood guidelines.

RESULTS

A gradual shift in the type of AGA from the earlier types (II and III) to more severe types (VI) with increasing age was significant. Twenty-seven patients did not fit into specific patterns according to Hamilton and Norwood classifications. In addition, type 'a' variant was recorded in 20% of patients, clearly indicating limitations of the existing classifications.

CONCLUSIONS

It was possible to classify 80% of the AGA, with II (28%) and III (15%) being the most common types of AGA. Twenty-seven patients (18%) could not be classified as a significant finding. There was considerable overlap in types IV, V and VI in the Norwood classification with the 'a' variants further confusing the picture.

A novel dodecapeptide from a combinatorial synthetic library exhibits potent antifungal activity and synergy with standard antimycotic agents

There has been a marked expansion in the discovery of new antifungal peptides. This paper describes a novel dodecapeptide, H-Arg-Trp-Trp-Arg-D-Trp-D-Phe-Ile-D-Phe-His-Trp-Arg-Trp-NH(2), derived from a previously described nonapeptide and synthesized by the combinatorial approach. Further, interaction of this peptide with antifungals such as amphotericin B, flucytosine and fluconazole was studied by checkerboard analysis and time-kill assay to obtain the dynamic picture with respect to time. The best synergistic activity was observed with a combination of peptide and fluconazole, followed by peptide and flucytosine.

Trichotillomania +/- trichobezoar: revisited

Trichotillomania is an intriguing psychosomatic entity in which there is an irresistible desire to pull out the hair from the scalp, eyelashes, eyebrows and other parts of the body. The process results in an instant release of tension, a sense of relief and security. However, non-scaring alopecia is its clinical presentation. The development of trichobezoar following ingestion of the pulled hair is its salient complication in a few cases. Subsequently, it may cause symptoms pertaining to the gastrointestinal tract culminating in intestinal obstruction, perforation, pancreatitis and obstructive jaundice. The Rapunzel syndrome (trichobezoar) may occur when gastrointestinal obstruction is produced by a rare manifestation of a trichobezoar with a long tail that extends to or beyond the ileocecal valve. In most cases in children, trichotillomania +/- trichobezoar is a habit disorder and thus has a better prognosis. However, in adults the psychopathology is usually deeper and thus entails a poor prognosis. The diagnosis is made after taking a thorough history, noting the clinical features and evaluating a hair-root examination, where telogen hair is (almost) completely lacking, which distinguish trichotillomania from other hair disorders. Treatment modalities vary in childhood and adult varieties. Apart from psychotherapy, the drug treatment involves several agents including selective serotonin reuptake inhibitors (SSRIs) and domipramine. Trichobezoar/Rapunzel syndrome requires surgical intervention.

The major 8p22 tumor suppressor DLC1 is frequently silenced by methylation in both endemic and sporadic nasopharyngeal, esophageal, and cervical carcinomas, and inhibits tumor cell colony formation

Identification of tumor suppressor genes (TSG) silenced by methylation uncovers mechanisms of tumorigenesis and identifies new epigenetic tumor markers for early cancer detection. Both nasopharyngeal carcinoma (NPC) and esophageal carcinoma are major tumors in Southern China and Southeast Asia. Through expression subtraction of NPC, we identified Deleted in Liver Cancer 1 (DLC1)/ARHGAP7 (NM_006094)--an 8p22 TSG as a major downregulated gene. Although expressed in all normal tissues, DLC1 was silenced or downregulated in 11/12 (91%) NPC, 6/15 (40%) esophageal, 5/8 (63%) cervical and 3/9 (33%) breast carcinoma cell lines. No genetic deletion of DLC1 was detected in NPC although a hemizygous deletion at 8p22-11 was found by 1-Mb array-CGH in some cell lines. We then located the functional DLC1 promoter by 5'-RACE and promoter activity assays. This promoter was frequently methylated in all downregulated cell lines and in a large collection of primary tumors including 89% (64/72) NPC (endemic and sporadic types), 51% (48/94) esophageal, 87% (7/8) cervical and 36% (5/14) breast carcinomas, but seldom in paired surgical marginal tissues and not in any normal epithelial tissue. The transcriptional silencing of DLC1 could be reversed by 5-aza-2'-deoxycytidine or genetic double knock-out of DNMT1 and DNMT3B. Furthermore, ectopic expression of DLC1 in NPC and esophageal carcinoma cells strongly inhibited their colony formation. We thus found frequent epigenetic silencing of DLC1 in NPC, esophageal and cervical carcinomas, and a high correlation of methylation with its downregulation, suggesting a predominant role of epigenetic inactivation. DLC1 appears to be a major TSG implicated in the pathogenesis of these tumors, and should be further tested as a molecular biomarker in patients with these cancers.

Identification of a tumor suppressive critical region mapping to 3p14.2 in esophageal squamous cell carcinoma and studies of a candidate tumor suppressor gene, ADAMTS9

A gene critical to esophageal cancer has been identified. Functional studies using microcell-mediated chromosome transfer of intact and truncated donor chromosomes 3 into an esophageal cancer cell line and nude mouse tumorigenicity assays were used to identify a 1.61 Mb tumor suppressive critical region (CR) mapping to chromosome 3p14.2. This CR is bounded by D3S1600 and D3S1285 microsatellite markers. One candidate tumor suppressor gene, ADAMTS9, maps to this CR. Further studies showed normal expression levels of this gene in tumor-suppressed microcell hybrids, levels that were much higher than observed in the recipient cells. Complete loss or downregulation of ADAMTS9 gene expression was found in 15 out of 16 esophageal carcinoma cell lines. Promoter hypermethylation was detected in the cell lines that do not express this gene. Re-expression of ADAMTS9 was observed after demethylation drug treatment, confirming that hypermethylation is involved in gene downregulation. Downregulation of ADAMTS9 was also found in 43.5 and 47.6% of primary esophageal tumor tissues from Hong Kong and from the high-risk region of Henan, respectively. Thus, this study identifies and provides functional evidence for a CR associated with tumor suppression on 3p14.2 and provides the first evidence that ADAMTS9, mapping to this region, may contribute to esophageal cancer development.

Prognostic quantification of non-small cell lung cancer metastases to the lung

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Background: Lung is the most frequent organ site of metastases from non-small cell lung cancer (NSCLC), yet the impact of these metastases on the natural history of the disease has not been well elucidated. Part of the difficulty of evaluating the prognosis of lung metastases in NSCLC patients is the effect of metastases to other organ sites. Here we have studied the survival of patients with lung as the solitary or dominant site of metastases and correlated it with number and maximal size of tumors. Methods: Data from the M.D. Anderson Cancer Center Tumor Registry during 1998 to 2002 was interrogated. Of 1280 patients registering as new patients, 87 were evaluable as having lung as the only site of metastases on initial staging evaluation. Excluding 13 patients who had bronchioloalveolar carcinoma (BAC) or BAC features on histology, the remaining 74 patients’ baseline CT scans were reviewed and scored for 1) the maximal linear measurement of the largest lung tumor and 2) the number of lung nodules that were growing and consistent with lung metastases. Results: In non-BAC patients with lung only metastases, an inverse correlation is seen between maximal linear measurement of a patient’s largest lung metastasis on baseline staging and their subsequent survival. A similar inverse correlation is seen between the number of lung metastases and survival. When patients with subsequent development of other metastatic sites are excluded from the analysis, these correlations are strengthened. Also, in BAC patients with lung only metastases, a trend toward longer survival with fewer metastases was seen, but only 13 patients were evaluable. Formal statistical analysis of these results is pending. Conclusions: The number and size of lung metastases from NSCLC appear to be independent predictors of survival. This might be explained by lead-time bias where fewer lesions represent an earlier stage of metastatic disease, however, increasing number and size of metastases may also be multiplying the source for further metastatic spread of disease. This interpretation of data may justify the local therapy of individual lung metastases in oligometastatic disease by surgery, stereotactic radiosurgery, or radiofrequency ablation.

No significant financial relationships to disclose.

Functional epigenetics identifies a protocadherin PCDH10 as a candidate tumor suppressor for nasopharyngeal, esophageal and multiple other carcinomas with frequent methylation

Protocadherins constitute the largest subgroup in the cadherin superfamily of cell adhesion molecules. Their major functions are poorly understood, although some are implicated in nervous system development. As tumor-specific promoter methylation is a marker for tumor suppressor genes (TSG), we searched for epigenetically inactivated TSGs using methylation-subtraction combined with pharmacologic demethylation, and identified the PCDH10 CpG island as a methylated sequence in nasopharyngeal carcinoma (NPC). PCDH10 is broadly expressed in all normal adult and fetal tissues including the epithelia, though at different levels. It resides at 4q28.3--a region with hemizygous deletion detected by array-CGH in NPC cell lines; however, PCDH10 itself is not located within the deletion. In contrast, its transcriptional silencing and promoter methylation were frequently detected in multiple carcinoma cell lines in a biallelic way, including 12/12 nasopharyngeal, 13/16 esophageal, 3/4 breast, 5/5 colorectal, 3/4 cervical, 2/5 lung and 2/8 hepatocellular carcinoma cell lines, but not in any immortalized normal epithelial cell line. Aberrant methylation was further frequently detected in multiple primary carcinomas (82% in NPC, 42-51% for other carcinomas), but not normal tissues. The transcriptional silencing of PCDH10 could be reversed by pharmacologic demethylation with 5-aza-2'-deoxycytidine or genetic demethylation with double knockout of DNMT1 and DNMT3B, indicating a direct epigenetic mechanism. Ectopic expression of PCDH10 strongly suppressed tumor cell growth, migration, invasion and colony formation. Although the epigenetic and genetic disruptions of several classical cadherins as TSGs have been well documented in tumors, this is the first report that a widely expressed protocadherin can also function as a TSG that is frequently inactivated epigenetically in multiple carcinomas.