Genetic localization of the Ca2+ channel gene CACNG2 near SCA10 on chromosome 22q13

PURPOSE

Voltage-dependent calcium channel mutations have been associated with spinocerebellar ataxia in humans (SCA6) and with ataxia, progressive cerebellar degeneration, and epilepsy in mice (tottering, lethargic, and stargazer). A novel autosomal dominant spinocerebellar ataxia syndrome with epilepsy (SCA10) was recently mapped to chromosome 22q13. The human ortholog of the mouse stargazer locus, the calcium channel gamma subunit gene CACNG2, also is located in this region. Because the phenotypes of stargazer mice and SCA10 patients were similar, consisting of both cerebellar ataxia and seizures, we hypothesized that CACNG2 was a likely candidate for the SCA10 locus.

METHODS

Polymerase chain reaction (PCR) based assays were developed for two polymorphic microsatellite markers near CACNG2. The location of CACNG2 was determined by linkage and haplotype analysis of the genotypes of 22 individuals from a human pedigree segregating SCA10.

RESULTS

SCA10 was previously localized distal to marker D22S1177 on chromosome 22q13. We determined that CACNG2 was linked to D22S283 and D22S1177 with the marker order: centromere-D22S283-bcmDLB1 (CACNG2)-D22S1177-D22S423-telomere. Thus CACNG2 is located proximal to the SCA10 recombinant interval.

CONCLUSIONS

Here we report the first genetic linkage of CACNG2 on chromosome 22q13 and exclude it as a candidate for SCA10. In addition, our data clarify the relation between the physical and genetic linkage maps of this region and will facilitate isolation of the SCA10 gene.

[Prediction of the clinical efficacy of hepatic arterial chemotherapy for metastatic hepatic cancer by intraarterial infusion of 99mTc-MIBI]

SPECT was performed in 11 patients with metastatic hepatic cancer by intraarterial infusion of 99mTc-MIBI before hepatic arterial chemotherapy was started, and the degree of accumulation and clinical efficacy were compared. Early and delayed SPECT images were obtained and various parameters were calculated, including early ratio (ER), delayed ratio (DR), washout rate (WR), and retention index (RI). Judgement of clinical efficacy was made by CT before and after hepatic arterial chemotherapy and was classified as effective, unchanged, and progressive groups. The mean values of ER and DR in the effective group were higher than those in the progressive group. No relationships were noted among the WR and RI values of the groups. The assessment of ER and DR using 99mTc-MIBI intraarterial SPECT is considered to be useful for prediction of the clinical efficacy of hepatic arterial chemotherapy for metastatic hepatic cancer.

[Two cases of recurrent gastric cancer for which combination chemotherapy with pirarubicin, cis-platinum and 5-fluorouracil were markedly effective]

In the treatment of 2 patients with recurrent gastric cancer who showed bone metastasis and lymph node recurrence, we administered 30 mg/body of pirarubicin (THP) on the first day of treatment, and 30 mg/body of cis-platinum (CDDP) and 500 mg/m2 of 5-fluorouracil (5-FU) for 3 days (FP therapy). Marked effects were achieved. Gastric cancer of Borrmann IV type was diagnosed in Case 1, and total gastrectomy was performed. The histological type was poorly differentiated adenocarcinoma, and the histological classification was II. A bone metastasis was found three years after operation. The patient was CR after three courses of treatment, and has survived for 2 years. In Case 2, advanced gastric cancer was treated with neoadjuvant chemotherapy and distal gastrectomy. The histological type was moderately differentiated adenocarcinoma, and the histological classification was IIIa. Obstructive jaundice due to lymph node recurrence developed 6 years after operation. Two courses of treatment were provided after PTCD, and PR was observed. The patient has survived for 3 months. Both patients exhibited mild side effects such as anemia and leukocytopenia, but no serious complications were observed. Although various dosage regimens of FP therapy have been investigated, there has been a certain limit to the response rate achieved by this therapy, and new protocols have been explored. We achieved marked effects in 2 patients by adding THP to FP therapy. These cases are reported here together with some discussion of cases reported in the literature.

Somatic sequence variation at the Friedreich ataxia locus includes complete contraction of the expanded GAA triplet repeat, significant length variation in serially passaged lymphoblasts and enhanced mutagenesis in the flanking sequence

The vast majority of Friedreich ataxia patients are homozygous for large GAA triplet repeat expansions in intron 1 of the X25 gene. Instability of the expanded GAA repeat was examined in 23 chromosomes bearing 97-1250 triplets in lymphoblastoid cell lines passaged 20-39 times. Southern analyses revealed 18 events of significant changes in length ranging from 69 to 633 triplets, wherein the de novo allele gradually replaced the original over 1-6 passages. Contractions and expansions occurred with equal frequency and magnitude. This behavior is unique in comparison with other large, non-coding triplet repeat expansions [(CGG)(n)and (CTG)(n)] which remain relatively stable under similar conditions. We also report a rare patient who, having inherited two expanded alleles, showed evidence of contracted GAA repeats ranging from nine to 29 triplets in DNA from two independent peripheral blood samples. The GAA triplet repeat is known to adopt a triplex structure, and triplexes in transcribed templates cause enhanced mutagenesis. The poly(A) tract and a 135 bp sequence, both situated immediately upstream of the GAA triplet repeat, were therefore examined for somatic mutations. The poly(A) tract showed enhanced instability when in cis with the GAA expansion. The 135 bp upstream sequence was found to harbor a 3-fold excess of point mutations in DNA derived from individuals homozygous for the GAA triplet repeat expansion compared with normal controls. These data are likely to have important mechanistic and clinical implications.

Very large (CAG)(n) DNA repeat expansions in the sperm of two spinocerebellar ataxia type 7 males

Genetic anticipation, i.e. increasing disease severity and decreasing age of onset from one generation to the next, is observed in a number of diseases, including myotonic dystrophy type 1, Huntington's disease and several of the spinocerebellar ataxias. All of these disorders are associated with the expansion of a trinucleotide repeat and array length is positively correlated with disease severity and inversely correlated with the age of onset. The expanded repeat is highly unstable and continues to expand from one generation to the next, providing a molecular explanation for anticipation. Spinocerebellar ataxia type 7 (SCA7) is one of the latest additions to the list of triplet repeat diseases and is distinct from the other SCAs in that it is accompanied by retinal degeneration. Pedigree analyses have previously revealed that the SCA7 repeat is highly unstable and liable to expand, in particular when transmitted by a male. Surprisingly, though, an under-representation of male transmission has also been reported. We now demonstrate directly by single molecule analyses that the expanded repeat is extraordinarily unstable in the male germline and biased toward massive increases. Nearly all of the mutant sperm of two SCA7 males contain alleles that are so large that most of the affected offspring would at best have a severe infantile form of the disease. Indeed, the gross under-representation of such very large expanded alleles in patients suggests that a significant proportion of such alleles might be associated with embryonic lethality or dysfunctional sperm.

Antitumor activity of KF22678, a novel thioester derivative of leinamycin

KF22678, a novel thioester derivative of leinamycin with the 1-oxo-1,2-dithiolane-3-one moiety, was examined for anti-tumor activity, toxicity in mice and activation mechanism. KF22678 showed a broad antitumor spectrum against human carcinoma xenografts (lung, colon, ovary and prostate). The efficacy of KF22678 was significantly higher than that of cisplatin. KF22678 exhibited low cross-resistance against various drug-resistant cell lines of MDR1 or MRP overexpressing human tumors, and, in addition, exhibited more potent antitumor activity in vivo than ADM against A2780/ADM and KB/MRP xenograft. DL-Buthionine sulfoximine (BSO) pretreatment significantly reduced intracellular glutathione (GSH) level in human lung carcinoma A549 cells, leading to decrease in the cytotoxicity of KF22678, whereas the cytotoxicity of melphalan was augmented by BSO pretreatment. DNA single-strand breaks (SSB) were observed in A549 cells treated with KF22678 and bleomycin. DNA SSB induced by KF22678 was greatly reduced in the presence of BSO in the cells, whereas DNA SSB induced by bleomycin was not. In addition, the antitumor activity of KF22678 against BSO-pretreated human lung carcinoma PC-9 tumor was significantly decreased. These results suggest that the activation of KF22678 by intracellular GSH might be important for DNA SSB and antitumor activity in vitro and in vivo.

Immunohistochemical and molecular analysis of giant cell carcinoma of the pancreas: a report of three cases

We performed molecular biological studies as well as immunohistochemical analysis of three cases of giant cell carcinoma of the pancreas. Histologically, one case was a pleomorphic giant cell carcinoma consisting of pleomorphic giant/ small cells and spindle cells, one an osteoclast-like giant cell tumor composed of osteoclastoid giant cells and pleomorphic small cells, and one a pleomorphic giant cell carcinoma with osteoclastoid giant cells. Immunohistochemically, pleomorphic giant cells and small pleomorphic cells were positive for epithelial and mesenchymal markers throughout the cases. Osteoclastoid cells were strongly positive for PG-M1 (CD68), but negative for lysozyme and epithelial markers. Pleomorphic spindle cells showed the same immunoreactivity as pleomorphic giant/small cells. Genetically, all cases contained a mutation in the K-ras (codons 12, 13) oncogene, but neither p53 (exons 5-8) nor p16INK4 (exons 1, 2) gene mutations were found in any case. Furthermore, Loss of heterozygosity (LOH) of the p53, p161NK4. APC, and DPC4 gene loci was not found in any of the cases. Immunohistochemical study demonstrated this tumor to be of epithelial origin with mesenchymal differentiation. Genetically, initiation of the tumor is similar to that of usual ductal adenocarcinoma, but progression might be rather different. The peculiar histologic and biologic features of this tumor would be the result of changes in other functional genes.

Mapping of the gene for a novel spinocerebellar ataxia with pure cerebellar signs and epilepsy

We investigated a family with a new type of autosomal dominant cerebellar ataxia (ADCA) in which pure cerebellar ataxia is often accompanied with epilepsy. No CAG repeat expansions were detected at the spinocerebellar ataxia (SCA) type 1, 2, 3, 6, or 7 locus, and SCAs 4 and 5 were excluded by linkage analysis. We found linkage between the disease locus and D22S274 (Zmax = 3.86 at theta = 0.00) and two other makers in 22q13-qter. Haplotype analysis of the crossover events and the multipoint linkage mapping localized the disease locus to an 8.8-cM region between D22S1177 and D22S1160.

[Nurses' knowledge of alcohol-related problems and their treatment: a comparison of nurses in general hospital and alcoholism treatment units]

Nurses have the most contact with patients in the clinical settings, and they play an important role in the guidance and education of patients. Nurses' basic knowledge of alcohol-related problems greatly influences early discovery of and early intervention against alcohol-related problems in general units (GU). In a study undertaken mainly to understand the status of nurses' knowledge in GU, a survey was performed to compare the knowledge and attitude of nurses working in GU and those with working in units specializing in the treatment of alcoholism (AU). For reference, we used the results of separate surveys performed previously on the general population. The results showed that, compared with nurses in AU, nurses in GU (1) were more tolerant of drinking, but (2) were more stigmatic concerning alcoholism, and (3) had little knowledge concerning alcohol-related problems. Nurses in GU tended to have less knowledge about alcohol-related problems than the general population. Moreover, the knowledge of nurses in AU could not be considered sufficient. This study suggested the need for basic education concerning alcohol-related problems and their treatment aimed at nurses.

The G209A mutation in the alpha-synuclein gene is not detected in familial cases of Parkinson disease in non-Greek and/or Italian populations

OBJECTIVE

To determine whether the G-to-A substitution at nucleotide 209 (G209A) mutation in the alpha-synuclein gene is responsible for familial Parkinson disease (PD) in the US population.

DESIGN

Polymerase chain reaction-based DNA analysis of consecutive patients with PD and family history of PD.

SETTING

A university-affiliated movement disorder clinic and a Veterans Affairs clinical research laboratory.

PATIENTS

Forty-four patients with PD and family history of PD and 29 patients with sporadic PD, all with no known Greek and/or Italian background.

RESULTS

None of the DNA samples showed the G209A mutation.

CONCLUSION

The G209A mutation is rare in US patients with familial PD.

Molecular and clinical studies in SCA-7 define a broad clinical spectrum and the infantile phenotype

OBJECTIVE

To screen for the SCA-7 mutation in autosomal dominant cerebellar ataxia (ADCA) families and study genotype/phenotype correlations.

BACKGROUND

The association of cerebellar ataxia and progressive pigmentary macular dystrophy clinically defines a distinct form of ADCA classified as SCA-7. SCA-7 is caused by expansion of a highly unstable CAG repeat that lies in the coding region of a novel gene on chromosome 3p12-13.

METHODS

We screened 51 ADCA kindreds, in which SCA-1, SCA-2, SCA-3, and SCA6 mutations had been excluded, for the SCA-7 mutation using primers that specifically amplify the SCA-7 CAG repeat.

RESULTS

The SCA-7 mutation was identified in 10 independent families. Normal alleles ranged from 7 to 16 repeats; expanded alleles ranged from 41 to 306 repeats. One allele with 36 repeats was found in an asymptomatic individual carrying an at-risk haplotype. SCA-7 presents a wide spectrum of clinical features including visual loss, dementia, hypoacusia, severe hypotonia, and auditory hallucinations. Juvenile SCA-7 occurs on maternal and paternal transmission of the mutation, whereas the infantile form occurs only on paternal transmission. An infant of African American descent carried the largest SCA-7 expansion (306 CAG repeats) and had severe hypotonia, congestive heart failure, patent ductus arteriosus, cerebral and cerebellar atrophy, and visual loss.

CONCLUSION

These data show a wide spectrum of phenotypic abnormalities in SCA-7 and define an infantile phenotype caused by the largest CAG repeat expansion described to date.

Synthesis and antitumor activity of leinamycin derivatives: modifications of C-8 hydroxy and C-9 keto groups

A series of leinamycin derivatives were synthesized and evaluated for antitumor activity. Modifications at C-8 and C-9 positions revealed a broad structure-activity relationship in vitro and some derivatives showed potent antiproliferative activity against HeLa S3 cells.

Antitumor activity of KW-2170, a novel pyrazoloacridone derivative

5-(3-Aminopropyl)amino-7,10-dihydroxy-2-(2-hydroxethyl)-aminoethyl -6H-pyrazolo[4,5,1-de]acridin-6-one dihydroxy-chloride (KW-2170), a novel derivative of pyrazoloacridone, was selected and evaluated for its antitumor activity and toxicity in mice. KW-2170 exhibited antitumor activity superior to adriamycin (ADM) against Sarcoma 180, breast carcinoma MM102 and fibrosarcoma Meth A inoculated s.c. in mice. Its therapeutic index (LD10/ED50) was higher than that of ADM on two murine carcinoma models, MM102 and Meth A. KW-2170 showed significant antitumor activity against 17 human tumor xenografts of a total of 24 tumors tested and the total tumor response rate by treatment with KW-2170 was significantly higher than that by ADM (70.8 versus 58.3%). In particular, human lung carcinoma was highly sensitive to KW-2170, and a marked tumor regression was observed on Lu-65 and Lu-99 human lung carcinoma xenograft models. Ovary and pancreas carcinomas were also sensitive to the drug. Additionally, its therapeutic index was also high on these human carcinoma models in comparison with that of ADM. The best antitumor efficacy of KW-2170 was observed by a weekly treatment schedule followed by a single treatment schedule and a successive administration schedule also tended to be toxic to the hosts. KW-2170 exhibited very low cross-resistance against four lines of multidrug resistant tumors expressing high levels of P-glycoprotein, and the drug showed significant antitumor activity against ADM-resistant human ovary carcinoma A2780/ADM and against nasopharynx carcinoma KB-A1 xenografts which were not sensitive to ADM. These results indicate that KW-2170 has a very potent antitumor activity and is feasible as a new antitumor drug against ADM-refractory solid tumors in clinics.

UCH9, a new antitumor antibiotic produced by Streptomyces: I. Producing organism, fermentation, isolation and biological activities

We developed a microbial prescreen using Bacillus stearothermophilus NUB3620 and bacteriophage TP-68 to detect potential antitumor compounds acting on DNA or topoisomerases. During the course of screening microbial cultures for their antibacteriophage activities, we found that Streptomyces sp. isolated from a soil sample collected in Iwakuni city, Yamaguchi prefecture, Japan, produced a new antitumor antibiotic, UCH9. UCH9 was isolated from culture broth by a combination of EtOAc extraction and column chromatography. UCH9 has a new structure related to the antitumor antibiotic chromomycins. It exhibited antimicrobial activity against Gram-positive organisms. UCH9 also showed cytotoxic activity against HeLa S3 cells with an IC50 value of 13 nM and exhibited antitumor activity in vivo against mouse leukemia P388.

Molecular basis of neuromuscular diseases

For many neuromuscular disorders, the chromosomal location is known, the causal gene has been identified, and direct application of this knowledge may be made in a clinical setting. The benefits resulting from molecular-based methods include improved diagnostic accuracy and genetic counseling for patients and other at risk family members. This chapter discusses in detail four of the most frequently encountered neuromuscular disorders. These diseases include spinal muscular atrophy, Charcot-Marie-Tooth neuropathy, Duchenne/Becker type muscular dystrophy, and myotonic dystrophy.