Clinical Diagnosis of Gastrointestinal Stromal Tumor (GIST): From the Molecular Genetic Point of View

Gastrointestinal stromal tumors (GISTs) originating from the interstitial cells of Cajal are mesenchymal tumors of the gastrointestinal tract and have been found to harbor c-KIT mutations and KIT (CD117) expression since 1998. Later, PDGFRA mutations, SDH alterations, and other drive mutations were identified in GISTs. In addition, more and more protein markers such as DOG1, PKCθ were found to be expressed in GISTs which might help clinicians diagnose CD117-negative GISTs. Therefore, we plan to comprehensively review the molecular markers and genetics of GISTs and provide clinicians useful information in diagnostic and therapeutic strategies of GISTs. Twenty years after the discovery of KIT in GISTs, the diagnosis of GISTs became much more accurate by using immunohistochemical (IHC) panel (CD117/DOG1) and molecular analysis (KIT/PDGFRA), both of which constitute the gold standard of diagnosis in GISTs. The accurately molecular diagnosis of GISTs guides clinicians to precision medicine and provides optimal treatment for the patients with GISTs. Successful treatment in GISTs prolongs the survival of GIST patients and causes GISTs to become a chronic disease. In the future, the development of effective treatment for GISTs resistant to imatinib/sunitinib/regorafenib and KIT/PDGFRA-WT GISTs will be the challenge for GISTs.

Asian Consensus Guidelines for the Diagnosis and Management of Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors originating in the gastrointestinal tract. With the introduction of molecular-targeted therapy for GISTs which has yielded remarkable outcomes, these tumors have become a model of multidisciplinary oncological treatment. Although Western clinical guidelines are available for GISTs, such as those published by the National Comprehensive Cancer Network (NCCN) and the European Society of Medical Oncology (ESMO), the clinical situations in Asian countries are different from those in Western countries in terms of diagnostic methods, surgical approach, and availability of new targeted agents. Accordingly, we have reviewed current versions of several GIST guidelines published by Asian countries (Japan, Korea, China, and Taiwan) and the NCCN and ESMO and discussed the areas of dissensus. We here present the first version of the Asian GIST consensus guidelines that were prepared through a series of meetings involving multidisciplinary experts in the four countries. These guidelines provide an optimal approach to the diagnosis and management of GIST patients in Asian countries.

Hemolytic uremic syndrome caused by enteroviral infection

A 4-year-old boy presented with enteroviral infection complicated with atypical hemolytic uremic syndrome (aHUS). Enterovirus RNA was detected by reverse transcription polymerase chain reaction (RT-PCR) of both blood and kidney biopsy specimens. A survey of the complement system did not reveal a specific complement defect. Supportive therapy with blood components transfusion, plasma therapy, and immunosuppressants was administered, however, renal function did not recover. The results of this report demonstrate that the enterovirus is the cause of aHUS.

Clinical outcome and pathological features associated with NRAS mutation in cutaneous melanoma

The effect of NRAS mutations on the pathological features and clinical outcomes in patients with cutaneous melanoma was compared with that of tumors containing BRAF(V600E) mutations and tumors wild type for both (WT). Clinical outcome data were obtained from a prospective cohort of 249 patients. Mutations involving NRAS and BRAF(V600E) were detected by PCR and were sequence verified. Cox proportional hazards regression was performed to relate NRAS and BRAF mutations to clinical outcome. Seventy-five percentage of NRAS mutations occurred in tumors >1 mm thick (BRAF(V600E) 40%, WT 34%); 75% of NRAS mutations had >1 mitosis/mm(2) (BRAF(V600E) 40%, WT 55%). When compared to WT, multivariate analysis of melanoma-specific survival (MSS) identified NRAS mutations as an adverse prognostic factor [hazard ratio (HR) 2.96; P = 0.04] but not BRAF(V600E) mutations (HR 1.73; P = 0.23). NRAS mutations were associated with thicker tumors and higher rates of mitosis when compared to BRAF(V600E) and WT melanoma and independently of this, with shorter MSS.

Effective salvage therapy of imatinib-resistant gastrointestinal stromal tumor with combination of imatinib and pegylated liposomal doxorubicin

Here we presented a 60-year-old Taiwanese man with advanced gastrointestinal stromal tumor. Disease progression was noted during imatinib treatment. Surgical resection was done and mutation analysis of KIT gene in all the resected tumors revealed deletion mutations of codons 558-565 in exon 11, whereas a missense mutation was also identified at codon 822 in exon 17 in one resected tumor. Patient's disease was refractory to escalating dose of imatinib and dasatinb. Surprisingly, combination of imatinib with pegylated liposomal doxorubicin produced a substantial response and resulted in a 5-month progression free period for this imatinib-resistant gastrointestinal stromal tumor.

p-Cresyl sulphate and indoxyl sulphate predict progression of chronic kidney disease

Background. Indoxyl sulphate (IS) and p-cresyl sulphate (PCS) are uraemic toxins that have similar protein binding, dialytic clearance and proinflammatory features. However, only a few prospective studies have evaluated possible associations between these two retained solutes and renal disease progression in chronic kidney disease (CKD) patients.

Methods. This prospective observational study evaluated independent associations between serum total IS and PCS with renal progression in a selected cohort of patients having different stages of CKD. Baseline PCS and IS were correlated with renal progression [defined as decrements in estimated glomerular filtration rate (eGFR) > 50% from baseline or progression to end-stage renal disease (ESRD)] and death during a follow-up period of 24 months.

Results. Of 268 patients, 35 (13.1%) had renal progression and 14 (5.2%) died after a mean follow-up of 21 ± 3 months. Univariate Cox regression analysis followed by multivariate analysis showed that high-serum PCS levels were associated with renal progression and all-cause mortality independent of age, gender, diabetes status, albumin levels, serum IS, serum creatinine, Ca × P product, intact parathyroid hormone, haemoglobin or high-sensitivity C-reactive protein level. Serum IS was only associated with renal progression; however, the predictive power of serum IS was weakened when serum PCS was also present in the analytical model.

Conclusions. In addition to traditional and uraemia-related risk factors such as renal function, serum IS and PCS levels may help in predicting the risk of renal progression in patients having different stages of CKD.

PIK3CA mutation occurs in nasopharyngeal carcinoma but does not significantly influence the disease-specific survival

This study was aimed to test whether PIK3CA, BRAF and RAS are mutated in nasopharyngeal carcinomas (NPCs) and, if so, to further determine whether such mutations affect patients' survival. For this purpose, a total of 73 NPCs were subjected to mutational analyses for PIK3CA (exons 4, 7, 9, and 20), BRAF (codon 600), and RAS (codons 12, 13 and 61). Clinicopathological characteristics were correlated to the mutation data. Survival rates were compared with the log-rank test. The result showed that the mutation rate of PIK3CA in NPC (n = 73) was 9.6%, whereas both BRAF (n = 65) and RAS (n = 45) were wild type in every specimen with adequate DNA for analysis. PIK3CA mutation was slightly influenced by sex (P = 0.0418, Fisher's exact test), but had no significant relationship to other clinicopathological characteristics. Disease-specific survival was not significantly affected by PIK3CA mutations (P = 0.8825, log-rank test), albeit it was slightly better in younger patients (< or = 35 vs. >35 years of age) (P = 0.0477). These findings show that mutated PI3K may be involved in the NPC tumorigenesis but does not affect patient's prognosis, suggesting that PI3K is a potential target in NPC for targeted therapeutics using specific kinase inhibitors.

Serum deprivation induces SV40 early promoter activity

Proliferation and the expression of proliferation-associated genes are modulated by changing the serum concentration in the media of cultured cells. To determine if activity of the SV40 early promoter is modulated by serum, we examined the expression of SV40 early promoter driven marker genes in murine BALB/c 3T3T cells following serum deprivation or serum stimulation. SV40-promoter-regulated beta-galactosidase and chloramphenicol acetyl transferase genes were studied following either transient or stable transfection. The results show that serum deprivation of growing cells induces SV40 promoter activity while serum stimulation of quiescent G0 cells suppresses it. Kinetic analyses show a significant induction of the SV40 promoter activity during the first 2 days of serum deprivation which is maintained at a high level for 15 days. The induction of reporter gene expression by serum deprivation was selective for the SV40 early promoter because such an effect was not observed using the Rous sarcoma viral promoter. Nuclear run-off assays further show that the transcription controlled by the SV40 early promoter is approximately twofold greater in cells rendered quiescent by serum deprivation for 72 h than in growing cells cultured in medium containing serum. These results suggest that one reason SV40 T transformed cells commonly fail to undergo quiescence following serum deprivation is that the SV40 promoter is induced.

Lack of prognostic value of EGFR mutations in primary resected non-small cell lung cancer

PURPOSE

To investigate the prognostic value of epidermal growth factor receptor (EGFR) mutations in a series of Taiwanese patients with primary resected lung adenocarcinomas never treated with epidermal growth factor receptor tyrosine kinase (TK) inhibitor.

PATIENTS AND METHODS

A total of 27 of 35 patients whose EGFR mutational status in exons 18, 19, and 21 of the TK domain had been previously determined using nested polymerase chain reaction (PCR) were included in this retrospective study. All 27 patients underwent potentially curative pulmonary resection. Clinicopathological information was obtained from patient records and pathology reports. Disease-free survival (DFS) and overall survival (OS) of patients were estimated with the Kaplan-Meier method, and Cox regression model was used for multivariate analysis.

RESULTS

Heterozygous EGFR mutations were detected in 15 of 27 patients (55.5%). There was no significant difference in DFS between patients with wild-type EGFR (median, 16.87 months) and mutant EGFR (median, 18.13 months; P = 0.83). No significant difference in OS was also noted between the wild-type and mutant groups (P = 0.45, median follow-up 22.6 months). Cox regression model and multivariate analysis of survival difference by age, stage, histology, and adjuvant treatment did not reach statistical significance.

CONCLUSION

EGFR mutations do not have significant prognostic value in primary resected non-small cell lung cancer (NSCLC), and further well-designed large prospective studies are warranted to determine the prognostic value of EGFR mutations in NSCLC.

PIK3CA exon 20 mutation is independently associated with a poor prognosis in breast cancer patients

BACKGROUND

Prognostic factors that could select breast cancer patients with poor survival, and influence clinical trials of targeted therapy, are needed. However, the reported observations regarding the impact of PI3KCA mutation on breast cancers are controversial.

METHODS

We analyzed exons 4, 7, 9, and 20 of PI3KCA on a series of 158 patients. Clinicopathological characteristics were correlated with the mutation data.

RESULTS

Among 152 patients who were available for follow-up (median follow-up time, 6.57 years), 26% had PIK3CA mutations, more than half of which occurred in exon 20. The five-year survival rate of patients with exon 20 mutations (46%) was significantly lower than that of patients without (75%) (p = 0.0054). Multivariate analysis showed that PIK3CA exon 20 mutations and nodal involvement were independent risk factors for overall survival. The relative risk of death in patients with PIK3CA exon 20 mutations was 2.881 (95% CI, 1.406-5.900; p = 0.0038).

CONCLUSIONS

PIK3CA mutations are common in invasive ductal carcinomas of the breast. Our result suggests that PIK3CA exon 20 mutation is an independent risk factor for poor prognosis in breast cancer patients, indicating that differences in patient numbers with PIK3CA exon 20 mutations in study and control arms should be avoided in clinical trials of PI3K inhibitors.

Anaplastic carcinoma of the thyroid arising more often from follicular carcinoma than papillary carcinoma

BACKGROUND

Anaplastic thyroid carcinoma (ATC), a rare and highly malignant tumor, has long been thought to arise from well-differentiated carcinoma (WDC) such as follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma (PTC). The purpose of this study was to test this notion by examining whether and, if so, how often ATC harbors the oncogenes that are commonly associated with WDC, such as RAS in FTC and BRAF in PTC.

METHODS

We analyzed the mutation hotspots of BRAF (codon 600) and N-, K-, and H-RAS (codons 12, 13, and 61) in 16 ATCs. We also examined two genes, PIK3CA (exons 9 and 20) and TP53 (exons 5-9), both of which have been reported in ATCs.

RESULTS

The results showed that approximately 31% (5 of 16) of ATCs harbored N-RAS mutation, 6% (1 of 16) had mutated BRAF, and approximately 56% (9 of 16) had mutated TP53. As to the three ATCs that had coexisted PTCs, mutated BRAF was detected in all PTC components but only in one ATC, while mutated PIK3CA was found in only one PTC component but not in the ATC.

CONCLUSION

A number of ATCs arise from WDCs, more often from RAS-mutant tumors than from BRAF-mutant tumors, implying that particular attention should be paid to the WDC harboring RAS mutation.

Spectrum and prognostication of KIT and PDGFRA mutation in gastrointestinal stromal tumors

AIMS

Recent studies reported various mutation rates in gastrointestinal stromal tumors (GISTs) and inconsistent prognostic value of mutation in GIST patients. Our purpose was to analyze the frequency and spectrum of KIT and PDFGRA in a large series study and to determine if the presence of mutation and mutation type serve as prognostic factors in GIST patients.

METHODS

A total of 134 GISTs were subjected to mutation analysis of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 10, 12, 14, and 18). Clinicopathologic characteristics and survivals were correlated to KIT mutation.

RESULTS

Approximately 69% of GISTs had KIT/PDGFRA mutation in Taiwanese GIST patients, with 99% of mutations occurred in KIT and 1% occurred in PDGFRA. Mutation rate was significantly increased in GISTs with mitotic counts >5 per 50 high power fields (chi(2) test, p=0.045). However, KIT mutations, regardless of the location (exons 9 versus 11) and type (missense, insertion, and deletion, including deletion specifically involving codons 557 and 558) of mutation, were not significantly associated with poor progression-free survivals. Comparing the overall survival in imatinib-treated patients, there was no significant difference between patients with exon 11 mutation and those with exon 9 mutation (p=0.473).

CONCLUSIONS

GISTs were commonly associated with KIT mutation, but rarely associated with PDGFRA mutation in Taiwan. The presence of KIT mutation and mutation type was not significant prognostic factors in GIST patients without imatinib treatment, suggesting that there is no need to stratify GIST patients by mutation status in clinical trials of targeted therapy.

Cloning of genes expressed in cell quiescence: a new function of the ras-recision/lysyl oxidase gene

The mechanism governing cell quiescence remains to be elucidated, albeit some tumor suppressor genes are known to be involved in this process. If more genes belonging to this regulatory circuit are identified, we will have a better understanding on cell quiescence. For this purpose, the present study was designed to clone genes preferentially expressed in cell quiescence. Using the method of differential display, we cloned ras-recision gene (rrg), also known as lysyl oxidase gene (lox), from BALB/c 3T3T cells, which were rendered quiescent by serum deprivation. Northern blot analysis showed that the induction of rrg/lox gene could be detected as early as 12 h following serum deprivation and it was dramatically elevated from 24 hours on after serum starvation. Induction of rrg/lox was also observed in cells rendered quiescent by contact inhibition, indicating that rrg/lox is induced by cell quiescence in general rather than specific to serum deprivation. Because rrg/lox gene products are known to be involved in extracellular matrix maturation, and function as tumor suppressors against ras oncogene, our finding suggests that quiescence-associated cell physiology is partly mediated by induction of rrg/lox.

ND4 mutation in transitional cell carcinoma: Does mitochondrial mutation occur before tumorigenesis?

To investigate how mitochondrial mutation occurs in cancers, we analyzed ND4 mutation in 53 transitional cell carcinomas (TCCs) of the upper urinary tract and the normal counterpart (perirenal soft tissue). Three methods, i.e., DNA sequencing, restriction fragment length polymorphism (RFLP), and denaturing high-performance liquid chromatography (DHPLC), were employed because of their different sensitive of detecting mutation. The results of sequencing and RFLP showed that ND4 mutations were only found in 24.5% (13/53) of tumor. However, 11 of these mutations could also be identified in the normal tissue by DHPLC, indicating that most mitochondrial mutations identified in tumors preexist as minor components, which are too low in quantity to be detected by less sensitive methods such as DNA sequencing. The result suggests that mtDNA mutation occurs before tumorigenesis and become apparent in cancer cells.

Prophylactic intravesical instillation of epinephrine prevents cyclophosphamide-induced hemorrhagic cystitis in rats

The objective of this study is to investigate the potential protective effects of intravesical instillation of epinephrine in cyclophosphamide-induced hemorrhagic cystitis. In an earlier study, we have shown that epinephrine promotes hemostasis on established hemorrhagic cystitis induced by cyclophosphamide. Female Sprague-Dawley rats were divided into seven groups as follows: group 1: positive control (150 mg/kg, cyclophosphamide, i.p.), group 2: negative control (10 microg/ml, epinephrine, intravesical), co-administration of cyclophosphamide (150 mg/kg, i.p.), group 3: saline (intravesical), groups 4-6: epinephrine (2.5, 5, and 10 mu g/ml, intravesical), and group 7: mesna (50 mg/kg, i.p.). Rats were sacrificed on 3 consecutive days and the urinary bladders were removed, weighed, and evaluated. The vesical vascular permeability was determined by wet bladder weight and Evan's blue dye absorbance. After 24 hours of cyclophosphamide administration, severe hemorrhagic cystitis was induced with marked edema, hemorrhage, and inflammation. In the epinephrine-treated groups, symptoms of hemorrhagic cystitis (such as edema, inflammation, and hemorrhage) were reduced significantly. Intravesical instillation of epinephrine prevents edema, hemorrhage, and inflammation in rats with cyclophosphamide-induced hemorrhagic cystitis.

Analysis of disease-associated ND4 mutations: How do we know which mutation is pathogenic?

It is not uncommon to identify more than one mtDNA replacement mutations in the specimens from patients. However, we usually do not know if the identified mtDNA mutation is pathogenic or not. Even functional assays are available to use, we would not know which mutation(s) is to be tested. To provide a rapid method for initial evaluation for the pathogenicity of the replacement mutation, we compared three evolutional analyses: primate conservation index (PCI), mammalian conservation index (MCI), and conservation index across a wide spectrum of species (CI). After analyzing 35 so-called diseases-associated replacement mutations of ND4, we found 8 pathogenic mutations, 15 nonpathogenic mutations, and 12 mutations of undetermined significance. The MCI classification appears to be the best one among the three systems. This study demonstrates that evolutional analysis can serve as a rapid evaluation for the pathogenicity of mtDNA replacement mutations.

Prenatal diagnosis and genetic counseling of mucopolysaccharidosis type II (Hunter syndrome)

We present prenatal diagnosis of mucopolysaccharidosis type II (MPS II) (Hunter syndrome) and demonstrate marked mucopolysaccharide deposition in multiple vital organs in a 22-gestational-week affected fetus. Level II ultrasound showed cardiomegaly and hepatomegaly. Histological examinations of the fetal vital organs manifested marked mucopolysaccharide deposition. We suggest that any therapeutic approach and counseling for prenatally diagnosed MPS II should consider the early signs of in utero marked mucopolysaccharide storage.

Incidence of gastrointestinal stromal tumor: a retrospective study based on immunohistochemical and mutational analyses

The aim of this study is to estimate the incidence of the gastrointestinal stromal tumor after the previous diagnoses were confirmed and/or revised by both immunohistochemical and mutational analyses. We reviewed 17,858 surgically excised gastrointestinal lesions in our hospital from 1998 to 2004. All mesenchymal tumors were examined for CD117 expression by immunohistochemistry, and every CD117-negative mesenchymal tumors were further subjected to mutational analysis for KIT and PDGFRA exons. The results showed that approximately 35% of gastrointestinal stromal tumors were misdiagnosed if immunohistochemical analysis of CD117 expression was not performed; and approximately 15% misdiagnosed if mutation analysis was not available. Because approximately 4.72% of patients with gastrointestinal malignancies in Taiwan were treated in our hospital and the average of newly diagnosed gastrointestinal stromal tumors in our hospital was 14.33 cases per year, the estimated annual incidents of gastrointestinal stromal tumor in Taiwan were 303.60. Therefore, the annual incidence of gastrointestinal stromal tumor is 13.74 per million Taiwanese.

Second-trimester diagnosis of limb-body wall complex with literature review of pathogenesis

Three fetuses having limb-body wall complex (LBWC) with craniofacial defects and 9 fetuses having LBWC without craniofacial defects were diagnosed and delivered in the second trimester at Mackay Memorial Hospital during the period January 1990 - May 2006. Cases of LBWC with craniofacial defects showed severe anomalies of the upper limbs, craniofacial defects, constrictive amniotic bands and cranioplacental attachment, whereas, cases of LBWC without craniofacial defects presented major anomalies of the lower limbs, abnormal genitalia, anal atresia, renal defects, abdominoplacental attachment and umbilical cord abnormalities. The perinatal findings of LBWC with or without craniofacial defects were compared and the pathogenesis was discussed.

Prenatal diagnosis of Dandy-Walker malformation associated with distal limb deficiencies

We report the perinatal findings of a 23 gestational-week fetus with Dandy-Walker malformation (DWM), ventriculomegaly, symmetrical transverse limb deficiencies, hypertelorism, frontal bossing, low-set ears, and a depressed nasal bridge. The karyotype was 46,XX. We believe that this combination is significant. Concomitant DWM and symmetrical distal limb deficiencies may represent a new entity that awaits more new cases for further delineation.

Disseminated cutaneous bacille Calmette-Guérin infection identified by polymerase chain reaction in a patient with X-linked severe combined immunodeficiency

An 8-month-old boy developed a disseminated cutaneous mycobacterial infection at 6 months of age that responded poorly to treatment. Further immunologic study and sequence analysis showed the presence of a missense mutation in the IL2RG gene, and X-linked severe combined immunodeficiency was diagnosed. To identify the strain of the microorganism causing the cutaneous infection, polymerase chain reaction with four pairs of primers was performed on skin biopsy specimens positive for acid-fast bacilli. Sequence analysis showed 99.36% homology with a bacilli Calmette-Guérin positive control. Disseminated bacilli Calmette-Guérin disease must be considered in any infant with cutaneous mycobacterial lesions, especially those with atypical histologic findings or who are immunocompromised. Testing by polymerase chain reaction using the proper primers may help in making a precise diagnosis.

Clinical implications of C-kit gene mutation in patients with large gastrointestinal stromal tumors

BACKGROUND AND AIM

To evaluate the clinical implications of C-kit gene mutation in patients with gastrointestinal stromal tumors (GIST) greater than 10 cm in size.

METHODS

All cases of pathologically diagnosed GIST with positive CD117 immunostaining from one hospital were retrospectively reviewed. Tissue from the 25 patients with tumors greater than 10 cm in diameter were collected and DNA was extracted. Exons 9, 11, and 13 of the C-kit gene were analyzed and the mutations compared with the clinical and pathological characteristics of the corresponding tumors.

RESULTS

Of the 25 tumors studied, 16 had C-kit gene mutations and nine did not. Of the 16 with mutations, there were four with exon 9 mutations, 12 with exon 11 mutations, and none with exon 13 mutations. Gene mutations were more frequent in male than female patients (12/13, 92% vs 4/12, 33%). There were no significant differences in age, resectability, recurrence rate, tumor characteristics (ulceration, necrosis, hemorrhage and mitotic counts), or survival in patients with or without gene mutations.

CONCLUSIONS

C-kit gene mutations were frequently found in patients with large GIST, more commonly in men than in women. However, the presence of a mutation was not predictive of prognosis in patients with large GIST.

Brain single photon emission computed tomography in patients with A3243G mutation in mitochondrial DNA tRNA

Brain single photon emission computed tomography (SPECT) studies were conducted in three patients with A3243G mutation of the mitochondrial (mt) DNA tRNA. All were born to mothers suffering from chronic progressive external ophthalmoplegia (CPEO) with the same A3243G point mutation of the mtDNA tRNA. The first case manifested clinically with MELAS, the second case manifested with CPEO, and third case was characterized by recurrent migraine-like headache, tremor, and epilepsy. Brain SPECT of all patients, regardless of whether they had or had not suffered from stroke-like episodes, showed multiple areas of asymmetrical decreased perfusion, particularly in the posterior and lateral head regions, especially the temporal lobes. Crossed-cerebellar diaschisis may occur. Conventional brain magnetic resonance images failed to show some of the lesions. Decreased regional cerebral blood flow, rather than previously proposed hyperemia, is likely to be the cause. We conclude that mitochondrial vasculopathy with regional cerebral hypoperfusion may be seen on brain SPECT in patients with mitochondrial disorders and A3243G mutations, regardless of whether they have or have not suffered from stroke-like episodes.

Identification of human-specific adaptation sites of ATP6

Mitochondria play an essential role in forming ATP and generating heat. The proportion of these two depends on the coupling efficiency of electrochemical gradient to synthesize ATP. Therefore, an increased basal metabolic rate caused by partial uncoupling of the mitochondria can be balanced by a high caloric intake provided by a high-fat diet. The recent study by Mishmar et al. (Proc. Natl. Acad. Sci. USA 2003; 100: 171-176) suggested that ATP6 was the most variable gene among human mitochondrial DNAs and probably resulted from the adaptation of Homo sapiens to the colder climate during the migration out of Africa. According to this adaptation theory, the ATP6 of Homo sapiens (omnivorous animals consuming fat-containing diet) should be significantly different from that of other primates for permitting human adaptation to the dietary conditions. On the basis of this rationale, we analyzed ATP6 sequences of 136 unrelated Taiwanese subjects, which then were compared with 1,130 reported sequences. The obtained human consensus from 1,266 individuals was compared with that derived from 42 species of primates other than human. The alignment showed that human ATP6 harbored 80 variable residues, among which 25 amino acids were conserved in other primates, suggesting that adaptation constraints operating at the amino acid level results in the species-specific difference of ATP6. Therefore, these 25 amino acids are probably the human-specific adaptation residues of ATP6.

Detection of mycobacteria in Crohn's disease by a broad spectrum polymerase chain reaction

BACKGROUND

The role of mycobacterial infection, particularly related to Mycobacterium avium subsp paratuberculosis (Map), in Crohn's disease has long been debated. We developed primer pairs capable of detecting a broad spectrum of mycobacterium and employed them to investigate surgical specimens from patients with Crohn's disease.

METHODS

Pan mycobacterium primers of the 65-kDa heat shock protein gene (Hsp65) were used in a polymerase chain reaction (PCR) to examine 12 surgically-resected, formalin-fixed, paraffin-embedded specimens from 11 patients with Crohn's disease. The DNA sequences of amplicons were aligned with those in GenBank.

RESULTS

Mycobacterial DNA was found in specimens from three of 11 patients. M. mucogenicum was identified in a specimen from one patient and M. tuberculosis in two, but Map was not identified in any.

CONCLUSION

Hsp65-based PCR can be employed to search for occult mycobacterial infection of the gastrointestinal tract in patients with a diagnosis or suspicion of Crohn's disease. This approach may have a therapeutic implication.

Oculopharyngeal somatic myopathy in a patient with a novel large-scale 3,399 bp deletion and a homoplasmic T5814C transition of the mitochondrial DNA

We report a 65-year-old woman with a sporadic form of progressive oculopharyngeal somatic myopathy due to a novel large-scale 3,399 base pair (bp) deletion of the mitochondrial DNA (mtDNA) and co-occurrence of a homoplasmic T5814C transition. The onset of myopathy began from chronic progressive external ophthalmoplegia (CPEO) at age of 20 years. Bulbar weakness, neck and proximal limb paralysis, slowly progressed to eventual respiratory failure. The plasma levels of pyruvate (1.5 mg/dL) and lactate (20.2 mg/dL) were elevated. Muscle biopsy showed decreased enzymatic activity of cytochrome c oxidase, but no ragged-red fibers. Electron microscopy showed "parking-lot" paracrystalline inclusions in the enlarged mitochondria suggestive for mitochondrial myopathy. Sequencing of the whole mitochondrial genome of the patient's muscle and leukocytes showed 3,399 bp deletion of the mtDNA from nucleotide position 8,024 to 11,423 and a homoplasmic thymidine to cytosine transition at nucleotide position 5,814 of the tRNA(Cys) gene of mtDNA (T5814C). T5814C was absent in the white blood cells of the patient's daughter and in 205 normal controls. We conclude that a large-scale deletion may coexist with T5814C transition in patients with sporadic form of mitochondrial cytopathy manifested by slowly progressive oculopharyngeal somatic myopathy.

Epinephrine promotes hemostasis in rats with cyclophosphamide-induced hemorrhagic cystitis

OBJECTIVES

To evaluate the hypothesis that intravesical instillation of epinephrine would attenuate bladder hemorrhage in a rat model of cyclophosphamide (CYP)-induced hemorrhagic cystitis.

METHODS

Female Sprague-Dawley rats were divided into seven treatment groups: positive control (CYP, 150 mg/kg), negative control (epinephrine, 10 microg/mL), intravesical instillation of normal saline (vehicle) and epinephrine (2.5, 5, and 10 microg/mL), and intraperitoneal administration of mesna (50 mg/kg). Rats were killed on days 1, 2, and 3, and the urinary bladders were removed, weighed, and evaluated by gross and histologic analysis. Vesical vascular permeability was determined by wet bladder weight and Evan's blue dye absorbance.

RESULTS

Cyclophosphamide administration induced severe hemorrhagic cystitis with marked edema, hemorrhage, and inflammation. All three epinephrine-treated groups had marked attenuation of hemorrhagic cystitis compared with the positive and negative control and mesna-treated groups. Epinephrine was also associated with significant inhibition of tissue edema, indicating decreased vesical vascular permeability.

CONCLUSIONS

In this rat model of CYP-induced hemorrhagic cystitis, intravesical instillation of epinephrine inhibited edema, hemorrhage, and inflammation.

Unexpected rapid progression of metastatic adenoid cystic carcinoma during treatment with imatinib mesylate

BACKGROUND

There is a lack of effective treatment for metastatic adenoid cystic carcinoma (ACC), a usually indolent tumor. We studied the efficacy of imatinib mesylate, a potent inhibitor of KIT tyrosine kinase, in patients with KIT-positive metastatic ACC.

METHOD

Five patients with lung metastasis were treated in a pilot study with imatinib 400 mg by mouth twice a day. Mutations of c-kit and platelet-derived growth factor receptor (PDGFR)-alpha in tumors from these patients were analyzed.

RESULTS

Disease progression was noted in three of five patients during the short treatment periods, ranging from 2 to 3 weeks. Three patients died of disease within 6 months. No detectable mutations were found in c-kit and PDGFR-alpha.

CONCLUSION

We observed an unexpected high progression rate of metastatic ACC within short periods during imatinib treatment. Use of imatinib to treat cancers without c-kit or PDGFR-alpha mutation should be approached with caution.

EGFR mutations in malignant pleural effusion of non-small cell lung cancer: a case report

EGFR mutations have been shown to correlate with the clinical responsiveness to epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). The detection of EGFR mutations in non-small cell lung cancer (NSCLC) is important from the perspective of targeted anticancer therapy. We report the first case showing that the status of EGFR mutations can be successfully determined in malignant pleural effusion of NSCLC using polymerase chain reaction (PCR) technique, and correlated to the clinical responsiveness to gefitinib, an EGFR-TKI. This case demonstrated the importance of molecular cytology in the era of targeted therapy.

Analysis of Heteroplasmy in Hypervariable Region II of Mitochondrial DNA in Maternally Related Individuals

Mitochondrial DNA sequences have been widely employed for identity investigation. However, the presence of a heteroplasmic site may complicate sequence analysis for forensic purposes when two samples are compared. To study this potential problem, we analyzed the hypervariable region of the displacement loop in five maternally related individuals, that is, grandmother, mother, one son, and two daughters. The results showed that three of them had a heteroplasmic site at nucleotide position (np) 204, located in the hypervariable region II. By using Bayesian inference to assess the significance of the mother-offspring pairs, a likelihood ratio of 1.78 x 10(5) was obtained. Therefore, Bayesian inference does not place the prior odds into the context of the two different likelihood ratios derived from the DNA evidence. On the other hand, the chromatogram of the denaturing high-performance liquid chromatography system proved that the single peak in a sequencing chromatogram at np 204 was, in fact, heteroplasmic in nature. This study demonstrated that heteroplasmy is a common occurrence in tissue from normal individuals and should be taken into account in forensic investigation when samples appear to differ at a single nucleotide position by direct sequencing.

Evolutional Analysis in Determining Pathogenic versus Nonpathogenic Mutations of ATPase 6 in Human Mitochondriopathy

Because mitochondrial ATPase 6 plays an important role in ATP synthesis, mutations affecting ATPase 6 can undoubtedly cause human diseases. In contrast, the ATPase 6 gene is known to be a fast-evolving gene and has generated enough polymorphisms to allow identity investigation for forensic casework. To investigate these seemingly opposite views, we analyzed amino acid sequences of ATPase 6 in at least 1,266 humans, 102 mammals, and 213 vertebrates. The result showed that the amino acids of human ATPase 6 could be divided into the following four groups. Amino acid residue 192 (affected by alteration at nt 9101) and 79 other residues were variable, and therefore substitutions of these residues would not be pathogenic. Amino acid residue 156 (affected by alteration at nt 8993) and 93 other residues were conserved in Homo sapiens, but not in Mammalia. Therefore, they were potentially pathogenic if altered. Function studies would be necessary to confirm their role in pathogenesis. Amino acid residue 217 (affected by alteration at nt 9176) and 9 other residues were conserved across all species, including S. cerevisiae and E. coli. Mutations involving these residues would be pathogenic, some of which might even be life threatening. The remainder (42 residues) were conserved in Mammalia, but not in yeast and E. coli. They were probably pathogenic if mutated. The classification proposed in this study may, therefore, provide an algorithm for a diagnostic approach when a newly identified change of ATPase 6 is suspected for human mitochondriopathy.

Renal Cell Carcinoma Producing Granulocyte Colony-stimulating Factor

Severe neutrophilia caused by renal cell carcinoma secreting granulocyte colony-stimulating factor (G-CSF) is a rare manifestation of renal cancer. A 70-year-old woman presented with a 2-year history of severe anemia, severe neutrophilia and elevated serum G-CSF, which completely resolved after radical nephrectomy. Histologic study revealed a histologically high-grade, stage pT1N0M0 renal cell carcinoma. Serum G-CSF level was elevated preoperatively and returned to normal postoperatively. Immunohistochemical study of the tumor tissue using anti-G-CSF monoclonal antibody revealed positive staining in the cancer cells. Careful follow-up of white blood cell count and physical examination for neck lymph node enlargement led to the timely identification of tumor recurrence 17 months after surgery, which resulted in prompt and successful salvage immunotherapy. In this case, G-CSF appeared to contribute to the leukocytosis, as both serum G-CSF level and white blood cell count closely correlated with the clinical tumor growth. White blood cell count should be closely monitored as an indicator of disease activity in patients with G-CSF-producing renal cell carcinoma.

Disseminated Bacille Calmette-Guérin disease as the initial presentation of X-linked severe combined immunodeficiency--a case report

Bacille Calmette-Guerin (BCG) vaccination is used to prevent severe M. tuberculosis infection. It has been used in many countries for a long time. However, complications do occur, including localized abscesses, regional lymphadenitis and disseminated disease. The latter is often associated with underlying immunodeficiency. We report an 8-month-old male infant presenting with cough and fever who had had a generalized pigmented skin rash for one month. Skin biopsy revealed mycobacterial infection, but his response to treatment was poor and he had a persistent mild fever. Immunological studies revealed an IgG of 49 mg/dl, IgA 4 mg/dl, IgM 28 mg/dl, IgE < 1 mg/dl, CD3 1.1%, CD4 0.6%, CD8 0.6%, CD19 93.9%, CD57 1.1%, activated T cells 0.9%, and CH50 < 6.3%. These findings are compatible with the diagnosis of T(-)B(+)NK- severe combined immunodeficiency. Sequence analysis was performed and showed the presence of missense mutation in IL2Rgamma gene. An X-linked recessive inheritance pattern was proved by sequence analysis of his mother and grandmother. In order to identify the strain of the microorganism, we reviewed pathology of the skin biopsy which consisted of diffuse histiocytic infiltrate with poorly formed granulomas and no necrosis and used polymerase chain reaction (PCR) with the stain-positive clinical specimen and verify the organism found in the child's biopsy as M. bovis BCG strain. The diagnosis of disseminated BCG disease must be considered in any infant with cutaneous mycobacterial lesions, especially with atypical histologic findings. Such a patient's immunologic status should be evaluated and further family study is suggested. A high index of suspicion is needed to make a timely diagnosis, as early intervention with intensive treatment and bone marrow transplantation may be life-saving.

Spontaneous rupture of recurrent gastrointestinal stromal tumor associated with neurofibromatosis type 1

The incidence of gastrointestinal stromal tumor (GIST) among neurofibromatosis type 1 (NF-1) patients is approximately 3.9-25%, and this relationship is generally considered to be non-coincidental. We report a patient with NF-1 who underwent laparotomy 3 times due to recurrent intra-abdominal tumor rupture with internal bleeding in the space of 13 years. The pathologic diagnoses were schwannoma, malignant peripheral nerve sheath tumor and GIST. Because of the similar histologic features of these tumors, we considered them to be of the same nature. Immunohistochemical staining can help in the differential diagnosis. We suggest that NF-1 patients with gastrointestinal symptoms receive further survey to rule out GISTs.

Quantitative analysis of plasma HBV DNA for early evaluation of the response to transcatheter arterial embolization for HBV-related hepatocellular carcinoma

AIM: To assesse changes in plasma HBV DNA after TAE in HBV-related HCC and correlate the levels with the pattern of lipiodol accumulation on CT.

METHODS: Between April and June 2001, 14 patients with HBV-associated HCC who underwent TAE for inoperable or recurrent tumor were studied. Levels of plasma HBV DNA were measured by real-time quantitative PCR daily for five consecutive days after TAE. More than twofold elevation of circulating HBV DNA was considered as a definite elevation. Abdominal CT was performed 1-2 mo after TAE for the measurement of lipiodol retention.

RESULTS: Circulating HBV DNA in 10 out of 13 patients was elevated after TAE, except for one patient whose plasma HBV DNA was undetectable before and after TAE. In group I patients (n = 6), the HBV DNA elevation persisted for more than 2 d, while in group II (n = 7), the HBV DNA elevation only appeared for 1 d or did not reach a definite elevation. There were no significant differences in age or tumor size between the two groups. Patients in group I had significantly better lipiodol retention (79.31±28.79%) on subsequent abdominal CT than group II (18.43±10.61%) (P = 0.02).

CONCLUSION: Patients with durable HBV DNA elevation for more than 2 d correlated with good lipiodol retention measured 1 mo later, while others associated with poor lipiodol retention. Thus, circulating HBV DNA may be an early indicator of the success or failure of TAE.

Mutation in the tyrosine kinase domain of epidermal growth factor receptor is a predictive and prognostic factor for gefitinib treatment in patients with non-small cell lung cancer

PURPOSE

Mutations in epidermal growth factor receptor (EGFR) can be used to predict the tumor response of patients receiving gefitinib for non-small cell lung cancer (NSCLC). We investigated the association between mutations in EGFR tyrosine kinase domain and tumor response and survival in gefitinib-treated NSCLC patients.

EXPERIMENTAL DESIGN

EGFR mutations in exons 18 to 21 were analyzed by DNA sequencing of paraffin-embedded tumor tissues from gefitinib-treated NSCLC patients. The results were correlated with clinical variables.

RESULTS

EGFR mutations were found in 61.1% (33 of 54) of cases; response rate and disease control rate were 56.8% and 68.5%, respectively. There was no significant difference in mutation rates between adenocarcinoma (29 of 43) and nonadenocarcinoma (4 of 11; P = 0.085). However, all four nonadenocarcinomas with EGFR mutations had no response to gefitinib. Presence of EGFR mutations was the only independent predictor for disease control (P = 0.003) and tumor response (P = 0.017) in multivariate analysis; positive predictive values were 87.9% and 70.8% and negative predictive values were 61.9% and 69.2%, respectively. In comparison with patients whose tumor was negative for EGFR mutations, patients with EGFR mutations had better progression-free survival (median, 7.6 versus 1.7 months; P = 0.011) and overall survival (median, 14.7 versus 4.7 months; P = 0.046).

CONCLUSIONS

Mutations in EGFR tyrosine kinase correlate with treatment response and survival in gefitinib-treated NSCLC patients and can be used as a predictive and prognostic factor. Thus, analysis of EGFR tyrosine kinase mutations in lung adenocarcinoma is of clinical significance, as it can permit the customization of treatment with EGFR tyrosine kinase inhibitors.