Calreticulin expression in neuroblastoma--a novel independent prognostic factor

BACKGROUND

Calreticulin (CRT), an endoplasmic reticulum protein, has been reported to be essential for the differentiation of neuroblastoma (NB) cells, suggesting that CRT may affect the tumor behavior of neuroblastoma. The aim of this study was to evaluate the association of clinicopathologic factors and patient survival with the expression of CRT in patients with NB.

PATIENTS AND METHODS

Sixty-eight NBs were investigated by immunohistochemical staining against CRT, and were divided into positive and negative immunostaining groups. Correlations between calreticulin expression, various clinicopathologic and biologic factors, and patient survival were studied. In seven tumor samples, CRT mRNAs and proteins were evaluated with real-time PCR and western blot, respectively, and correlated with immunohistochemical findings.

RESULTS

Among 68 NBs, 32 (47.1%) showed positive CRT expression. Positive CRT immunostaining strongly correlated with differentiated histologies, as well as known favorable prognostic factors such as detected from mass screening, younger age (< or =1 year) at diagnosis and early clinical stages, but inversely correlated with MYCN amplification. Kaplan-Meier analysis revealed that NB patients with CRT expression did have better survival. Multivariate analysis demonstrated CRT expression to be an independent prognostic factor. Moreover, CRT expression also predicted better survival in patients with advanced-stage NBs, and its absence predicted poorer survival in patients whose tumor had no MYCN amplification. The amount of CRT mRNAs and proteins in NB tumor samples tested correlated well with the immunohistochemical expressions.

CONCLUSIONS

CRT expression correlates with the differentiation of NB and predicts favorable survival, thereby suggesting CRT to be a useful indicator for planning treatment of NB.

Clinicopathological and molecular biological features of colorectal cancer in patients less than 40 years of age

BACKGROUND

The aim of the present study was to identify the clinicopathological and molecular biological characteristics of early-onset colorectal cancers.

METHODS

The clinicopathological and molecular biological parameters of 138 consecutive patients with colorectal cancer aged less than 40 years were compared with those of 339 patients aged 60 years or more.

RESULTS

The younger patients with colorectal cancer had more mucin-producing (14.5 versus 4.7 per cent; P < 0.001) and poorly differentiated (7.2 versus 3.3 per cent; P = 0.015) tumours, a higher incidence of synchronous (5.8 versus 1.2 per cent; P = 0.007) and metachronous (4.0 versus 0.6 per cent; P = 0.023) colorectal cancers, and more advanced tumour stage (P < 0.001) than older patients. The operative mortality rate was lower (0.7 versus 5.0 per cent; P = 0.026), and cancer-specific survival was similar (in stage I, II and III disease; P > 0.05) or better (in stage IV disease; 95 per cent confidence interval 22.50 to 28.41 versus 12.61 to 17.05 months; P < 0.001). There was a higher percentage of normal p53 expression (61.1 versus 46.8 per cent; P = 0.023) and high-frequency microsatellite instability (MSI-H) (29.4 versus 6.3 per cent; P < 0.001), and a similar family history of cancer (17.5 versus 14.2 per cent; P > 0.05), compared with older patients.

CONCLUSION

Young patients with colorectal cancer have several distinct clinicopathological and molecular biological features. The mechanisms underlying the inconsistency between the presence of MSI-H and a family history of cancer in these early-onset colorectal cancers deserve further investigation.

Congenital generalized lipodystrophy in a 4-month-old infant

Congenital generalized lipodystrophy (CGL, Berardinelli-Seip syndrome) is a rare autosomal recessive disorder with a clinical presentation of paucity of adipose tissue, muscular hypertrophy, organomegaly, and insulin-resistant diabetes. A 4-month-old Taiwanese female infant had hepatosplenomegaly and low body weight gain despite a voracious appetite. Hypermetabolism, hyperhidrosis, loss of subcutaneous fat, muscular hypertrophy, acanthosis nigricans, hypertrichosis, and marked hypertriglyceridemia were also noted. Liver histology revealed fatty change and portal-to-portal bridging fibrosis. Clinical features, serum biochemistry, and liver histology were compatible with the diagnosis of CGL. She was given a special diet characterized by calorie restriction and partial substitution of long-chain triglycerides with medium-chain triglycerides. The serum triglyceride concentration subsequently decreased. This present case suggests that extensive fatty infiltration and subsequent cirrhosis of the liver may be the earliest complication of CGL.

Prevalence and rapid identification of clarithromycin-resistant Helicobacter pylori isolates in children

BACKGROUND

Little is known about the prevalence of antibiotic-resistant Helicobacter pylori infection in children. Culture and antimicrobial susceptibility testing are generally time-consuming and not a routine in many hospitals.

OBJECTIVE

To investigate the prevalence of clarithromycin-resistant H. pylori strains in children, to identify those isolates via rapid methodology and to examine the severity of gastritis caused by the antibiotic-resistant H. pylori isolates.

METHODS

Enrolled were 245 children investigated for H. pylori infection by endoscopic examination. The gastric antral specimens were subjected to DNA extraction and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with primers specific to the H. pylori 23S rRNA gene. Conventional bacterial cultures were performed simultaneously as the diagnostic standard. Minimal inhibitory concentrations of clarithromycin and metronidazole were determined by E test. This was used as a standard to determine the sensitivity and specificity of the above PCR-RFLP assay. The specimens were processed for histologic examination and evaluated by the updated Sydney system.

RESULTS

H. pylori was isolated in 67 of the 245 children; 12 (18%) of them were clarithromycin-resistant and 6 (9%) were metronidazole-resistant. No difference in histologic examinations was noted between the antibiotic-resistant and -susceptible strains. We performed PCR-RFLP with all 12 clarithromycin-resistant isolates: 10 had a 23S ribosomal RNA A2144G point mutation; 1 had a mixture of an A2143G point mutant and susceptible strains; and 1 had neither of the 2 mutations.

CONCLUSIONS

The prevalence of clarithromycin-resistant H. pylori isolates in Taiwanese children is 18%. PCR-RFLP had a high sensitivity (92%) and specificity (100%) for the clarithromycin resistance gene mutation determination. The dominant mutation is A2144G. PCR-RFLP provides a rapid and accurate approach to detect clarithromycin-resistant strains within 24 h.

Progressive familial intrahepatic cholestasis with high gamma-glutamyltranspeptidase levels in Taiwanese infants: role of MDR3 gene defect?

MDR3 P-glycoprotein mediates canalicular phospholipid transport in hepatocytes. Defects in the MDR3 gene have been found to cause a subtype of progressive familial intrahepatic cholestasis (PFIC) with high gamma-glutamyltranspeptidase (GGT) levels. Affected children develop proliferation of biliary epithelium, portal inflammation, and biliary cirrhosis. The frequency of MDR3 mutations in patients with high GGT-PFIC is unclear. There have been no Asian patients reported to carry MDR3 mutations. To determine the role of MDR3 defects in chronic cholestatic patients, we studied six Taiwanese children from five families who presented high GGT-PFIC among 47 patients with infantile onset chronic intrahepatic cholestasis. Sequence analysis of MDR3 cDNA from liver tissues was performed. Only one patient had mutation in the MDR3 gene. This patient had a homozygous 719-bp deletion (nucleotide 287 to 1005) of liver cDNA encompassing exon 5 to 9 and leading to protein truncation. The onset age was 1 y in contrast with the other five patients who presented neonatal cholestasis. Four patients without mutation, including one sibling pair, exhibited histologic features of prominent portal fibrosis leading to advanced biliary cirrhosis that were indistinguishable from the case of MDR3 mutation. We concluded that mutations in MDR3 accounted for approximately 2% (1/47) of infantile onset chronic cholestasis in Taiwan. Those patients presenting high GGT-PFIC with early onset cholestasis but without MDR3 mutation probably had inheritable disorders remaining to be clarified.

Tumor angiogenesis and its possible role in intravasation of colorectal epithelial cells

PURPOSE

To determine whether an increase in tumor angiogenesis facilitates intravasation of colorectal epithelial cells, we compared intratumoral microvessel counts with the presence of circulating colorectal epithelial cells in the portal venous blood from patients with colorectal carcinomas.

EXPERIMENTAL DESIGN

Circulating colorectal epithelial cells were detected by a reverse transcription-PCR assay to amplify guanylyl cyclase C (GCC) transcripts. The extent of tumor vascularization was quantitatively assessed by immunohistochemical staining with anti-CD31 antibody.

RESULTS

Colorectal epithelial cells (as measured by GCC mRNA expression) were detected in the portal venous blood in 30 of 58 patients (52%). The mean (+/- SD) microvessel count in the tumors from patients with expression of GCC mRNA in their portal venous blood was 82.74 +/- 24.97. The corresponding values in the tumors from patients without expression of GCC mRNA in portal venous blood was 65.96 +/- 19. For each 10-microvessel increase per x200 field, the risk of colorectal epithelial cell presence in the portal venous blood increased 1.52-fold (95% confidence interval, 1.19-2.12; P = 0.005).

CONCLUSION

High intratumoral vessel count was noted to be a valuable factor for predicting the presence of colorectal epithelial cells in the portal venous blood.

Lymphoepithelioma-like cholangiocarcinoma: an Epstein-Barr virus-associated tumor

Epstein-Barr virus (EBV) has been linked to carcinomas of several body sites, especially of the nasopharynx, salivary gland, lung, and stomach. We present five cases of lymphoepithelioma-like cholangiocarcinoma, including one that had been previously reported. Two patients were men and three were women. Their ages ranged from 42 to 66 years. Histologically, all five tumors were composed of variable proportions of undifferentiated epithelial cells and glandular components in a lymphocyte-rich stroma. EBV was detected in all five tumors by in situ hybridization for EBER-1 in both lymphoepithelioma-like carcinoma (LELC) and glandular parts, but not in 36 cases of cholangiocarcinoma without the LELC component. Taken together, these observations indicate that lymphoepithelioma-like cholangiocarcinoma is strongly linked to EBV. The LELC type of cholangiocarcinoma, like LELC of other body sites, may be more common in areas with endemic EBV infection.

Expression of mutant nuclear beta-catenin correlates with non-invasive hepatocellular carcinoma, absence of portal vein spread, and good prognosis

beta-catenin has functions both in the cadherin-mediated cell adhesion system and in the signalling pathway that mediates dorsal axis patterning in the embryo; it has been shown to be aberrantly expressed or mutated in diverse types of human tumour, but the biological significance of this remains to be clarified. To elucidate the clinical implications of aberrant beta-catenin expression and the potential differences between mutant and wild-type beta-catenin protein expression in hepatocellular carcinoma (HCC), the protein expression was analysed by immunohistochemical staining, supplemented by the analysis of gene mutation. Among 372 unifocal primary HCCs, beta-catenin was detected in the tumour cell membrane alone in 272 tumours (group A) and also in the nuclei in 100 (group B). In group A, 148 tumours had decreased beta-catenin expression, but the reduction did not correlate with invasion or prognosis. When compared with group A, however, group B had significantly lower frequencies of hepatitis B surface antigen carrier (p=0.015), and alpha-fetoprotein elevation (p=0.0003), but more often had non-invasive HCC (p<0.001) and better survival (p=0.01). Nuclear beta-catenin expression strongly correlated with mutation of the gene (p<0.00001). In group B, HCC with mutant nuclear beta-catenin correlated positively with non-invasive (stage 1) tumour and inversely with portal vein tumour thrombi (stage 3 HCC), and had significantly better 5-year survival, p<0.001 and p<0.0003, respectively. These results suggest that beta-catenin mutation plays an important role in the tumourigenesis of a subset of HCC of good prognosis, and that mutant and wild-type nuclear beta-catenin proteins are not functionally equivalent.

Expression of mutant nuclear beta-catenin correlates with non-invasive hepatocellular carcinoma, absence of portal vein spread, and good prognosis

beta-catenin has functions both in the cadherin-mediated cell adhesion system and in the signalling pathway that mediates dorsal axis patterning in the embryo; it has been shown to be aberrantly expressed or mutated in diverse types of human tumour, but the biological significance of this remains to be clarified. To elucidate the clinical implications of aberrant beta-catenin expression and the potential differences between mutant and wild-type beta-catenin protein expression in hepatocellular carcinoma (HCC), the protein expression was analysed by immunohistochemical staining, supplemented by the analysis of gene mutation. Among 372 unifocal primary HCCs, beta-catenin was detected in the tumour cell membrane alone in 272 tumours (group A) and also in the nuclei in 100 (group B). In group A, 148 tumours had decreased beta-catenin expression, but the reduction did not correlate with invasion or prognosis. When compared with group A, however, group B had significantly lower frequencies of hepatitis B surface antigen carrier (p=0.015), and alpha-fetoprotein elevation (p=0.0003), but more often had non-invasive HCC (p<0.001) and better survival (p=0.01). Nuclear beta-catenin expression strongly correlated with mutation of the gene (p<0.00001). In group B, HCC with mutant nuclear beta-catenin correlated positively with non-invasive (stage 1) tumour and inversely with portal vein tumour thrombi (stage 3 HCC), and had significantly better 5-year survival, p<0.001 and p<0.0003, respectively. These results suggest that beta-catenin mutation plays an important role in the tumourigenesis of a subset of HCC of good prognosis, and that mutant and wild-type nuclear beta-catenin proteins are not functionally equivalent.

Congenital interstitial cell of cajal hyperplasia with neuronal intestinal dysplasia

Interstitial cells of Cajal (ICCs) are intestinal pacemaker cells that initiate peristalsis in the stomach and intestine, and are considered to be precursors of gastrointestinal stromal tumors (GISTs). We report a 2-year-old girl who suffered from scanty stool passage since birth. On barium enema, the distal colon was rigid with narrow lumen, whereas the proximal colon was dilated and atonic. She received right hemicolectomy and ileostomy. Histopathologically, there was continuous proliferation of spindle cells located between the layers of the muscularis propria throughout the right colon. These spindle cells were positive for c-kit and CD34 but negative for myogenic or neurogenic markers, indicating they are ICCs. No germline or somatic mutation of the juxtamembrane domain of c-kit gene was detected. In addition, the changes of the submucosal plexus fulfilled the histologic criteria of neuronal intestinal dysplasia type B. To our knowledge, this is the first reported case of congenital ICC hyperplasia. Further studies of ICC development may contribute to better understanding of the pathogenesis of this congenital malformation and the tumorigenesis of GIST.

Beta-catenin mutations are associated with a subset of low-stage hepatocellular carcinoma negative for hepatitis B virus and with favorable prognosis

To better understand the role of beta-catenin mutation in hepatocellular carcinoma (HCC), we correlated the gene mutation with hepatitis virus B (HBV) and hepatitis virus C (HCV) status and the clinicopathological features in 366 patients with resected primary unifocal HCC. beta-Catenin mutations were also analyzed in 55 patients with multifocal HCC (68 tumors). Of the whole series, 57 (13.1%) of 434 tumors examined had beta-catenin mutations, 34 occurred at the serine/threonine residues of the GSK-3beta region of beta-catenin. Outside the GSK-3beta phosphorylation site, codons 32 and 34 were two mutational hot spots (17 tumors). The non-HBV-related HCC that was predominantly HCV related had a higher frequency of mutation (P: < 0.00001) and more frequent mutations at codon 45 than HBV-related HCC. HBV-related HCC had a younger mean age (P: < 0.00001), and higher male-to-female ratio (P: < 0.003) and positive familial history of HCC (P: < 0.014). Among 366 unifocal HCCs selected for clinicopathological analysis, beta-catenin mutations were associated with grade I (P: = 0.005) and stage I and II HCC (P: < 0.0001), and a better 5-year survival rate (P: = 0. 00003). These findings suggest mechanisms for beta-catenin mutations differ between HBV-related and non-HBV-related HCCs, and that beta-catenin mutation is a favorable prognostic factor related to low stage. beta-Catenin mutation was associated with nuclear expression of the protein (P: < 0.00001), but we failed to detect point or large fragment deletion mutation in 39 HCCs with nuclear beta-catenin expression, presumably wild-type protein. HCCs expressing mutant nuclear beta-catenin had a better 5-year survival rate (P: < 0.007), suggesting that mutant and wild-type nuclear beta-catenin proteins are not functionally equivalent and deserve more studies for further clarification.

Expression of the c-kit protein is associated with certain subtypes of salivary gland carcinoma

The c-Kit protein, a receptor type tyrosine kinase that plays an important role in the development of hematopoietic cells, melanocytes, and germ cells, is expressed in mastocytosis, gastrointestinal stromal cell tumors (GISTs), germ cell tumors, and several other tumors. Gain-of-function mutations in exon 11 and exon 17 have been shown as a mechanism of c-kit activation in some tumors. To study the role of c-kit in salivary gland carcinomas, we analyzed the c-kit protein expression in 79 carcinomas of major and minor salivary glands by immunohistochemistry. Although varying in intensity of staining, c-kit expression was identified very often in adenoid cystic carcinomas (20/25), lymphoepithelioma-like carcinomas (6/6) and myoepithelial carcinomas (2/2), but not in other types of salivary gland carcinoma (0/46), P<0.00001. By DNA sequencing, genetic alteration of c-kit juxtamembrane domain (exon 11) and tyrosine kinase domain (exon 17) was not found in all the three types of salivary carcinoma that had c-kit protein expression. In conclusion, c-kit protein overexpression is involved in the pathogenesis of certain types of salivary gland carcinoma, but mutation of the gene is not the mechanism of c-kit activation.

Somatic mutations of beta-catenin play a crucial role in the tumorigenesis of sporadic hepatoblastoma

Hepatoblastoma (HB) is the most common malignant hepatic tumor during early childhood. Its molecular pathogenesis is still poorly understood. Mutations of adenomatous polyposis coli (APC) gene have been identified in sporadic cases and in individuals associated with familial adenomatous polyposis syndrome. beta-catenin is a key element in the cadherin-mediated cell adhesion system and Wnt/wingless pathway, and is controlled by APC. APC affects the degradation of beta-catenin by its NH(2)-terminal phosphorylation on the serine/threonine residues of exon 3. Mutations of these phosphorylation sites are primary targets for activating mutations in several types of human cancer and lead to nuclear accumulation of beta-catenin protein. In this study, we examined nine patients with HB using immunohistochemistry and direct DNA sequencing. All nine cases showed predominant nuclear expression of beta-catenin. Eight cases (89%) showed mutations involving exon 3 of the beta-catenin gene, including five with deletions and three with missense mutations. All five deletions were in-frame deletions without frameshift. The very high frequency of mutations in the beta-catenin gene suggests that beta-catenin mutations are crucial in the tumorigenesis of HB.

Concordant body stalk anomaly in monozygotic twinning--early embryo cleavage disorder

We describe a case of concordant body stalk anomaly in monozygotic twins that manifested with umbilical cord agenesis, evisceration of abdominal contents, and multiple gastrointestinal, genitourinary, and skeletal anomalies. Body stalk anomaly in twin gestation is extremely rare and poses an embryological interest. We suggest that the hypothesis of 'incomplete twinning' might contribute to the pathogenesis of this syndrome complex.

Hepatoblastoma in an infant with Beckwith-Wiedemann Syndrome

A 3-month-old Chinese male infant with typical manifestations of Beckwith-Wiedemann Syndrome (BWS), such as macroglossia, hepatomegaly, umbilical hernia and hypoglycemia, presented with a large hepatic tumor. The tumor measured 7.6 x 8.0 x 7.5 cm. An open biopsy of the tumor revealed hepatoblastoma. The family refused chemotherapy, so only supportive care was given. The tumor grew very rapidly and the infant died 17 days after admission due to respiratory failure. To our knowledge, this is the first report of BWS associated with hepatoblastoma in a Chinese infant. This patient was a typical example of the association of BWS and hepatoblastoma, and the possible effect of growth factors on the rapid proliferation of the neoplasm in BWS.

Phenytoin-induced pseudolymphoma: reevaluation using modern molecular biology techniques

Patients receiving phenytoin (PHT) may develop pseudolymphoma or, rare ly, malignant lymphoma. Previously, distinguishing the two diseases based solely on histopathology has been difficult. The recent introduction of molecular biologic techniques has provided a powerful tool to reassess this problem. A 17-year-old girl developed systemic lymphadenopathy after receiving PHT for 1 year for generalized tonic-clonic seizures (GTCS). Biopsy of a cervical lymph node showed diffuse proliferation of large lymphoid cells mimicking a large cell lymphoma. Immunophenotypic, immunoglobulin gene rearrangement, and cytogenic studies, however, showed polyclonal B-cell proliferation, consistent with PHT-induced pseudolymphoma. After PHT discontinuation, lymphadenopathy resolved in 1 month and no recurrence developed in the subsequent 10 months. Obtaining a history of drug use is crucial to recognizing this group of patients. Molecular biology and chromosome studies have become the definitive basis differentiating pseudolymphoma from malignant lymphoma in patients receiving chronic PHT therapy.