Effect of metabolic and antioxidant supplementation on sperm parameters in oligo-astheno-teratozoospermia, with and without varicocele: A double-blind placebo-controlled study

Since sperm require high energy levels to perform their specialised function, it is vital that essential nutrients are available for spermatozoa when they develop, capacitate and acquire motility. However, they are vulnerable to a lack of energy and excess amounts of reactive oxygen species, which can impair sperm function, lead to immotility, acrosomal reaction impairment, DNA fragmentation and cell death. This monocentric, randomised, double-blind, placebo-controlled trial investigated the effect of 6 months of supplementation with l-carnitine, acetyl-l-carnitine and other micronutrients on sperm quality in 104 subjects with oligo- and/or astheno- and/or teratozoospermia with or without varicocele. In 94 patients who completed the study, sperm concentration was significantly increased in supplemented patients compared to the placebo (p = .0186). Total sperm count also increased significantly (p = .0117) in the supplemented group as compared to the placebo group. Both, progressive and total motility were higher in supplemented patients (p = .0088 and p = .0120, respectively). Although pregnancy rate was not an endpoint of the study, of the 12 pregnancies that occurred during the follow-up, 10 were reported in the supplementation group. In general, all these changes were more evident in varicocele patients. In conclusion, supplementation with metabolic and antioxidant compounds could be efficacious when included in strategies to improve fertility.

Acetyl-L-Carnitine Modulates TP53 and IL10 Gene Expression Induced by 3-NPA Evoked Toxicity in PC12 Cells

The neurotoxicity induced by the mitochondrial inhibitor 3-nitropropionic acid (3-NPA) is associated with a decrease of ATP synthesis and an increase of free radical production which can lead to apoptosis or necrosis. We have used the PC12, neuron-like rat pheochromocytoma cell line, to study further the mechanism of 3-NPA-evoked neurotoxicity and the effects of acetyl-L-carnitine (ALC) which has neuroprotective actions against various types of mitochondrial inhibitors.

Cultured PC 12 cells were exposed to a low dose of 3-NPA 50 (microM) in the presence or absence of 5 mM ALC. The dose of 3-NPA was sub toxic and no changes in pro-apoptotic Bax or anti-apoptotic Bcl-2 gene expression were observed. We followed specific genetic markers to look for changes evoked by 3-NPA toxicity and also changes associated with neuroprotection exerted by the ALC treatment, using RT-PCR arrays (delta-delta method). 3-NPA exposure evoked a decrease in expression of the Tp53 gene. This down regulation was prevented by pretreatment of the cells with ALC. The Tp53 gene responds to cellular stresses and the effects seen here are possibly associated with the 3-NPA evoked changes in mitochondrial metabolism. Other genes associated with stress and apoptosis, Parp-1, Bcl-2, and Bax were not affected by 3-NPA or ALC. The decrease of inflammatory response Il-10 gene expression due to 3-NPA was further lowered by presence of ALC. Other inflammation related genes, Il1rn, Nr3c1 and Cxcr4 were not affected. Interestingly, the glutamate transporter slc17a7, carnitine-acylcarnitine translocase Slc25a20 and heat shock proteins genes, Hsp27, Hmox1 (Hsp32, HO1) as well as Hspa 1a (Hsp 70) increased only when both ALC and small dose of 3-NPA were present. The alterations in gene expression detected in this study suggest role of several intracellular pathways in the neurotoxicity of 3-NPA and the neuroprotection against 3-NPA-induced neurotoxicity by ALC.

A noncoding RNA gene on chromosome 10p15.3 may function upstream of hTERT

Background

We attempted to clone candidate genes on 10p14–15 which may regulate hTERT expression, through exon trapping using 3 BAC clones covering the region. After obtaining 20 exons, we examined the function of RGM249 (RGM: RNA gene for miRNAs) we cloned from primary cultured human hepatocytes and hepatoma cell lines. We confirmed approximately 20 bp products digested by Dicer, and investigated the function of this cloned gene and its involvement in hTERT expression by transfecting the hepatoma cell lines with full-length dsRNA, gene-specific designed siRNA, and shRNA-generating plasmid.

Results

RGM249 showed cancer-dominant intense expression similar to hTERT in cancer cell lines, whereas very weak expression was evident in human primary hepatocytes without telomerase activity. This gene was predicted to be a noncoding precursor RNA gene. Interestingly, RGM249 dsRNA, siRNA, and shRNA inhibited more than 80% of hTERT mRNA expression. In contrast, primary cultured cells overexpressing the gene showed no significant change in hTERT mRNA expression; the overexpression of the gene strongly suppressed hTERT mRNA in poorly differentiated cells.

Conclusion

These findings indicate that RGM249 might be a microRNA precursor gene involved in the differentiation and function upstream of hTERT.

Evaluation of the efficacy of propionyl-L-carnitine versus pulsed muscular compressions in diabetic and non-diabetic patients affected by obliterating arteriopathy Leriche stage II

AIM

The effectiveness of propionyl-L-carnitine (PLC) monotherapy regimen alone or in association with pulsed muscular compression was compared to the physical therapy by itself against obliterant arteriopathy Leriche Fontaine stage II. PLC is involved in cellular metabolism and is transformed into two active substances, free L-carnitine and propionyl-coenzyme A in the mitochondria, which take part in fatty acid transfer and in the citric acid cycle, respectively.

METHODS

Forty-two patients with arterial disease were selected (22 males and 20 females; mean age: 62+/-8 years; 21 type 2 diabetic [DB] and 21 non-DB [NDB]). At enrollment all patients completed a symptoms questionnaire enabling both clinical and social evaluation of the impact of the arteriopathy on the quality of life. Then, patients had: routine blood samples, echo duplex scan; evaluation of the ankle/arm (Winsor) index; impedance plethysmography (Rheoscreen) to measure the crest time (CT), index of the pathological changes due to the sclerosis on the vascular wall, and measurement of walking distance by means of treadmill test. Patients were randomized in three groups, each of them composed by 14 patients (7 DB and 7 NDB): the first group was submitted to infusional PLC therapy at a dosage of 4 fl (total: 1,200 mg PLC) in 250 cc of physiological solution for 5 days a week for 4 weeks; the second group was treated with PLC in association with pulsed muscular compression therapy by Vascupump (5 sessions a week for 4 weeks); the third group was submitted only to Vascupump.

RESULTS

The efficacy of both PLC and Vascupump in the treatment of the peripheral vasculopathies was confirmed. From a subjective point of view, patients referred benefits both in clinical terms, i.e. increased walking distance (average increaseaegroup I: DB 102%, NDB 118%; group II: DB 94%, NDB 193%; group III: DB 33%, NDB 67%) and of decreased intensity of the calf pain from the quality of life questionnaire (21.5 to 10.7). The instrumental parameters showed a trend towards normality, i.e decrease in CT and an increase of the Winsor index, indicators of increased peripheral blood circulation.

CONCLUSION

Combined pharmaco- and physical therapy was most efficient treatment regime and best results were seen in NDB compared to the DB patients.

L-carnitine protects neurons from 1-methyl-4-phenylpyridinium-induced neuronal apoptosis in rat forebrain culture

1-Methyl-4-phenylpyridinium ion (MPP+), an inhibitor of mitochondrial complex I, has been widely used as a neurotoxin because it elicits a severe Parkinson's disease-like syndrome with an elevation of intracellular reactive oxygen species (ROS) and apoptosis. L-carnitine plays an integral role in attenuating the brain injury associated with mitochondrial neurodegenerative disorders. The present study investigates the effects of L-carnitine against the toxicity of MPP+ in rat forebrain primary cultures. Cells in culture were treated for 24 h with 100, 250, 500 and 1000 microM MPP+ alone or co-incubated with L-carnitine. MPP+ produced a dose-related increase in DNA fragmentation as measured by cell death ELISA (enzyme-linked immunosorbent assay), an increase in the number of TUNEL (terminal dUTP nick-end labeling)-positive cells and a reduction in the mitochondrial metabolism of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). No significant effect was observed with the release of lactate dehydrogenase (LDH), indicating that cell death presumably occurred via apoptotic mechanisms. Co-incubation of MPP+ with L-carnitine significantly reduced MPP+-induced apoptosis. Western blot analyses showed that neurotoxic concentrations of MPP+ decreased the ratio of BCL-X(L) to Bax and decreased the protein levels of polysialic acid neural cell adhesion molecules (PSA-NCAM), a neuron specific marker. L-carnitine blocked these effects of MPP+ suggesting its potential therapeutic utility in degenerative disorders such as Parkinson's disease, Alzheimer's disease, ornithine transcarbamylase deficiency and other mitochondrial diseases.

Aberrant methylation of the cyclin D2 promoter in primary small cell, nonsmall cell lung and breast cancers

DNA methylation alteration of several genes contributes to human tumorigenesis. Cyclin D2, a member of the D-type cyclins, is implicated in cell cycle regulation and malignant transformation. In our study, we examined the methylation status of the cyclin D2 promoter in small cell lung cancer (SCLC), nonsmall cell lung cancer (NSCLC), breast tumors and tumor cell lines. We observed that aberrant methylation of cyclin D2 was present in 32 of 56 (57%) SCLC cell lines, 7 of 32 (22%) SCLC tumor tissues; 25 of 61 (47%) NSCLC cell lines, 19 of 48 (40%) NSCLC tumor tissues; 18 of 30 (60%) breast tumor cell lines and 19 of 63 (30%) breast tumor tissues. Methylation was more frequent in the tumor cell lines compared to the primary breast and SCLC tumors (p = 0.007 and p = 0.001, respectively). Methylation was rare in the control tissue samples; 0 of 12 peripheral blood lymphocytes; 0 of 12 buccal epithelial cells; 0 of 18 nonmalignant lung tissues and 3 of 28 (11%) nonmalignant breast tissues. Promoter methylation correlated with loss of transcript by reverse transcription PCR (RT-PCR) in 9 of 11 (6 lung, 5 breast) tumor cell lines tested. Two cell lines that were not methylated also lacked expression, suggesting that other mechanisms of inactivation may be involved. Expression was restored by treatment with the demethylating agent, 5 aza 2' deoxycytidine, in all 9 methylated cell lines. Our results confirm earlier reports in breast cancer and indicate that aberrant methylation of cyclin D2 may contribute to the pathogenesis of the 2 major types of lung cancers.

Aberrant methylation of TMS1 in small cell, non small cell lung cancer and breast cancer

TMS1 (target of methylation-induced silencing) is a CpG island-associated gene that functions in the regulation of apoptosis and encodes a caspase recruitment domain, a recently described motif found in apoptotic signaling molecules. Recent evidence suggests that silencing of genes in the apoptotic pathway contribute to human carcinogenesis. We examined the DNA methylation status of the TMS1 promoter in lung and breast tumor tissues, tumor cell lines and nonmalignant tissues by methylation-specific polymerase chain reaction (MSP) and its mRNA expression by reverse transcription PCR. Aberrant methylation of TMS1 was present in 70% (40 of 57) of small cell lung cancer (SCLC) cell lines and 41% (13 of 32) of SCLC tumor tissues, 48% (29 of 61) of non small cell lung cancer (NSCLC) cell lines and 40% (28 of 70) of NSCLC tumor tissues and 46% (12 of 26) of breast cancer cell lines and 32% (20 of 63) of breast tumor tissues. Methylation was absent in the peripheral blood lymphocytes and buccal epithelium from healthy volunteers, as well as in nonmalignant lung tissues and was rare in nonmalignant breast tissues 7% (2 of 30). DNA methylation was confirmed by sequence analysis and the methylation status correlated inversely with TMS1 RNA expression in 18 cell lines tested. RNA expression was restored by treatment with the demethylating agent 5-aza-2'-deoxycytidine, in 4 of 4 methylated cell lines that lacked the TMS1 transcript. Our results suggest that methylation of TMS1 may play a role in the pathogenesis of small cell and non small lung and breast cancers.

Clinical relevance of reverse transcriptase-polymerase chain reaction for the detection of axillary lymph node metastases in breast cancer

BACKGROUND

The mammary sentinel lymph node procedure can increase the detection of axillary metastases by 45% compared with standard axillary dissection. Some investigators have reported that reverse transcriptase-polymerase chain reaction (RT-PCR) increases metastasis detection even more, but it is uncertain whether a positive RT-PCR test in the face of a negative histological evaluation is clinically meaningful.

METHODS

RT-PCR for epithelial glycoprotein 2 and cytokeratin 19 was performed on sentinel and pooled nonsentinel axillary lymph nodes from 108 women with clinical stage I or II breast cancer who were followed up for a median of 40 months.

RESULTS

Axillary metastases were detected on standard tissue sections in 26% and by RT-PCR in 30%. Results for the two tests were concordant for 80% of the cases. RT-PCR upstaged 16%. Tumors from women whose lymph nodes were positive only by RT-PCR were phenotypically similar to those from women with no metastases detected by any method. Moreover, 4-year actuarial distant disease-free survival was 100% for women with metastases detected by RT-PCR only, as compared with 74% for those with metastases detected by routine histology (P =.03) and 93% for those with no metastases detected by either method (P =.04).

CONCLUSIONS

Analysis of sentinel lymph nodes by RT-PCR for epithelial glycoprotein 2 and cytokeratin 19 is unlikely to provide clinically useful information.

Loss of retinoic acid receptor beta gene expression is linked to aberrant histone H3 acetylation in lung cancer cell lines

Most lung cancer cell lines do not express retinoic acid receptor (RAR)-beta in response to all-trans retinoic acid (RA) because of a defect in RARbeta gene transcription(RA-refractory cells). Here we investigated mechanisms of RA refractoriness in 14 lung cancer cell lines. Eleven cell lines were found to be RA refractory, and in the other three cell lines, RARbeta levels increased with RA treatment (RA-responsive cells). We observed RARbeta promoter methylation in 7 of 11 RA-refractory cell lines (64%) and in 0 of the 3 RA-responsive cell lines. Treatment with 5-aza-2'-deoxycytidine restored RA response in two of the seven cell lines with RARbeta promoter methylation (29%). RA treatment increased acetylation of histones H3 and H4 on chromatin of the RARbeta promoter in RA-responsive cells. Only histone H4 acetylation increased in RA-refractory cells, including refractory cells with and without evidence of promoter methylation. Thus, loss of histone H3 acetylation consistently correlated with RA refractoriness in lung cancer cell lines. RA refractoriness and aberrant histone acetylation were attributable to RARbeta promoter methylation in some cell lines but not in others, suggesting that multiple mechanisms contribute to this transcriptional defect in lung cancer cells.

Death receptor recruitment of endogenous caspase-10 and apoptosis initiation in the absence of caspase-8

Caspase-8 is believed to play an obligatory role in apoptosis initiation by death receptors, but the role of its structural relative, caspase-10, remains controversial. Although earlier evidence implicated caspase-10 in apoptosis signaling by CD95L and Apo2L/TRAIL, recent studies indicated that these death receptor ligands recruit caspase-8 but not caspase-10 to their death-inducing signaling complex (DISC) even in presence of abundant caspase-10. We characterized a series of caspase-10-specific antibodies and found that certain commercially available antibodies cross-react with HSP60, shedding new light on previous results. The majority of 55 lung and breast carcinoma cell lines expressed mRNA for both caspase-8 and -10; however, immunoblot analysis revealed that caspase-10 protein expression was more frequently absent than that of caspase-8, suggesting a possible selective pressure against caspase-10 production in cancer cells. In nontransfected cells expressing both caspases, CD95L and Apo2L/TRAIL recruited endogenous caspase-10 as well as caspase-8 to their DISC, where both enzymes were proteolytically processed with similar kinetics. Caspase-10 recruitment required the adaptor FADD/Mort1, and caspase-10 cleavage in vitro required DISC assembly, consistent with the processing of an apoptosis initiator. Cells expressing only one of the caspases underwent ligand-induced apoptosis, indicating that each caspase can initiate apoptosis independently of the other. Thus, apoptosis signaling by death receptors involves not only caspase-8 but also caspase-10, and both caspases may have equally important roles in apoptosis initiation.

hTR repressor-related gene on human chromosome 10p15.1

Somatic cells express genes that suppress telomerase activity and these genes may be inactivated in tumour cells. We postulated that cancer cells acquire immortality by activation of telomerase by the loss of such a gene. We have reported recently that a telomerase repressor gene may be located on 10p15.1 by deletion mapping using microcell-mediated chromosome transfer (MMCT), radiated microcell fusion (RMF), fluorescent in situ hybridization (FISH) and STS analysis. To independently confirm this result, we correlated expression of RNA component of telomerase (hTR) as a marker of telomerase expression by in situ hybridization with allelic loss in pulmonary carcinoid tumours. Unlike most malignant tumours, pulmonary carcinoids (which are low-grade malignant tumours) are heterogeneous for telomerase expression. Loss of 5 closely spaced polymorphic markers on 10p15.1, especially D10S1728, were highly correlated with hTR expression. In an additional experiment, 10p15.1 showed higher and more significant correlation than any region of 3p where it has been predicted as another chromosomal location of telomerase repressor with allelic loss of the region. Our findings strongly suggest that 10p15.1 harbours a gene involved in repression of telomerase RNA component in human somatic cells and each putative repressor (on 3p and 10p) may act independently.

Short tandem repeat profiling provides an international reference standard for human cell lines

Cross-contamination between cell lines is a longstanding and frequent cause of scientific misrepresentation. Estimates from national testing services indicate that up to 36% of cell lines are of a different origin or species to that claimed. To test a standard method of cell line authentication, 253 human cell lines from banks and research institutes worldwide were analyzed by short tandem repeat profiling. The short tandem repeat profile is a simple numerical code that is reproducible between laboratories, is inexpensive, and can provide an international reference standard for every cell line. If DNA profiling of cell lines is accepted and demanded internationally, scientific misrepresentation because of cross-contamination can be largely eliminated.

Epigenetic inactivation of RASSF1A in lung and breast cancers and malignant phenotype suppression

BACKGROUND

The recently identified RASSF1 locus is located within a 120-kilobase region of chromosome 3p21.3 that frequently undergoes allele loss in lung and breast cancers. We explored the hypothesis that RASSF1 encodes a tumor suppressor gene for lung and breast cancers.

METHODS

We assessed expression of two RASSF1 gene products, RASSF1A and RASSF1C, and the methylation status of their respective promoters in 27 non-small-cell lung cancer (NSCLC) cell lines, in 107 resected NSCLCs, in 47 small-cell lung cancer (SCLC) cell lines, in 22 breast cancer cell lines, in 39 resected breast cancers, in 104 nonmalignant lung samples, and in three breast and lung epithelial cultures. We also transfected a lung cancer cell line that lacks RASSF1A expression with vectors containing RASSF1A complementary DNA to determine whether exogenous expression of RASSF1A would affect in vitro growth and in vivo tumorigenicity of this cell line. All statistical tests were two-sided.

RESULTS

RASSF1A messenger RNA was expressed in nonmalignant epithelial cultures but not in 100% of the SCLC, in 65% of the NSCLC, or in 60% of the breast cancer lines. By contrast, RASSF1C was expressed in all nonmalignant cell cultures and in nearly all cancer cell lines. RASSF1A promoter hypermethylation was detected in 100% of SCLC, in 63% of NSCLC, in 64% of breast cancer lines, in 30% of primary NSCLCs, and in 49% of primary breast tumors but in none of the nonmalignant lung tissues. RASSF1A promoter hypermethylation in resected NSCLCs was associated with impaired patient survival (P =.046). Exogenous expression of RASSF1A in a cell line lacking expression decreased in vitro colony formation and in vivo tumorigenicity.

CONCLUSION

RASSF1A is a potential tumor suppressor gene that undergoes epigenetic inactivation in lung and breast cancers through hypermethylation of its promoter region.

Two identical triplet sisters carrying a germline BRCA1 gene mutation acquire very similar breast cancer somatic mutations at multiple other sites throughout the genome

Monozygotic twins, each of whom has breast cancer, offer a natural study population for gene-environmental interactions as causation of cancer, because they are genetically identical. If heritable factors play a large role in the origin of a neoplasm, disease concordance should be significant in monozygotic twins. Two monozygotic triplet sisters carrying a germline BRCA1 gene mutation (5382insC) who both developed breast cancer at early ages were studied for loss of heterozygosity (LOH) in their microdissected, paraffin-embedded tumors along with control blood and stromal breast tissue at 19 chromosomal arms using 161 microsatellite markers. Microdissected areas of normal lobular and ductal epithelium and ductal in situ carcinoma were also studied for LOH using a subset of microsatellite markers. The mother's DNA (extracted from peripheral blood lymphocytes) was analyzed to determine the parental allele under LOH in each case. Both tumors demonstrated similar histologic features suggestive of a secretory variant of ductal carcinoma. The tumors from both sisters had similar overall LOH frequency expressed by the fractional allelic loss (FAL) indices (0.56 vs. 0.60) and demonstrated concordance for loss or retention at 82 of 97 informative markers (85% correlation). In addition, detailed mapping analysis of several chromosomal arms revealed that identical breakpoints were detected in both tumors at several chromosome regions. Finally, in both sisters' tumors, when a chromosome exhibited allelic loss, all of the markers exhibited LOH of the same parental allele even when there were intervening regions of retention of heterozygosity. In contrast, 17 archival sporadic breast carcinomas demonstrated a wide range of FAL indexes and highly individual patterns of LOH. Our findings support the hypothesis that inherited factors play a role in the development of the multiple somatic deletions occurring in breast carcinomas. Whether one of these factors is the mutant BRCA1 allele or some other gene(s) remains to be determined. Genes Chromosomes Cancer 28:359-369, 2000.

Refined mapping of two regions of loss of heterozygosity on chromosome band 11q23 in lung cancer

11q23-24 chromosome is a region containing frequent allelic loss (loss of heterozygosity; LOH) in human cancers. To examine cancer-related allelic loss in the region between D11S940 and APOC3, we used 17 polymorphic markers and allotyped 28 lung cancer-derived cell lines and their corresponding matched lymphoblastoid cell lines. LOH was found in 71.4% (20/28) of the lung cancer cell lines and was localized to two distinct minimal regions of loss. One region is bracketed by markers D11S1647 and NCAM2 and contains the gene encoding the beta isoform of the A subunit of the human protein phosphatase 2A (PPP2R1B). Recently, mutations in this gene were described in lung and colon cancers, suggesting that PPP2R1B functions as a tumor-suppressor gene. A second minimal region of loss was defined between markers D11S1792 and D11S1885, a region estimated to be less than I Mb. Thus, chromosome 11 likely harbors two sites of suppressor oncogene activity in lung cancer, one defined by the PPP2R1B gene and the second located telomeric to PPP2R1B. This study facilitates the identification and cloning of a second critical tumor-suppressor gene involved in lung cancer, and possibly a variety of other cancers, on human chromosome band 11q23.

Characterization of paired tumor and non-tumor cell lines established from patients with breast cancer

The goal of our study was to develop a panel of tumor cell lines along with paired non-malignant cell lines or strains collected from breast cancers, predominantly primary tumors. From a total of 189 breast tumor samples consisting of 177 primary tumors and 12 metastatic tissues, we established 21 human breast tumor cell lines that included 18 cell lines derived from primary tumors and 3 derived from metastatic lesions. Cell lines included those from patients with germline BRCA1 and FHIT gene mutations and others with possible genetic predisposition. For 19 tumor cell lines, we also established one or more corresponding non-malignant cell strains or B lymphoblastoid (BL) lines, which included 16 BL lines and 7 breast epithelial (2) or stromal (5) cell strains. The present report describes clinical, pathological and molecular information regarding the normal and tumor tissue sources along with relevant personal information and familial medical history. Analysis of the breast tumor cell lines indicated that most of the cell lines had the following features: they were derived from large tumors with or without axillary node metastases; were aneuploid and exhibited a moderate to poorly differentiated phenotype; were estrogen receptor (ER)- and progesterone receptor (PR)-negative; and overexpressed p53 and HER2/neu proteins. Of 13 patients with primary breast cancers receiving curative intent mastectomies, 7 were dead after a mean period of 10 months. Our panel of paired tumor and non-malignant cell lines should provide important new reagents for breast cancer research.

Mutation analysis of the PTEN/MMAC1 gene in lung cancer

We studied PTEN/MMAC1, a newly discovered candidate tumor suppressor gene at 10q23.3, for mutations in lung cancer. One hundred and thirty-six lung cancer cell line DNAs (66 small cell lung cancers, SCLC, 61 non-small cell lung cancers, NSCLC, four mesotheliomas, five extrapulmonary small cell cancers) were analysed for PTEN/MMAC1 homozygous deletions and five (8%) SCLC lines showed homozygous deletions interrupting the PTEN/MMAC1 gene. Using single stranded conformation polymorphism (SSCP) analysis, we screened the PTEN/MMAC1 open reading frame of 53 lung cancer cell line cDNAs for point mutations and found that 3/35 SCLCs and 3/18 NSCLCs contained homozygous amino acid sequence altering mutations. Northern blot analysis revealed that expression of the PTEN/MMAC1 gene was considerably lower in all the tumor cell lines with point mutations while no expression was detected for cell lines with PTEN/MMAC1 homozygous deletions. Mutation analysis of 22 uncultured, microdissected, primary SCLC tumors and metastases showed two silent mutations, and two apparent homozygous deletions. We also discovered a processed pseudogene (PTEN2) which has 98.5% nt identity to PTEN/MMAC1, that needs to be accounted for in cDNA mutation analysis. Our findings suggest that genetic abnormalities of the PTEN/MMAC1 gene are only involved in a relatively small subset of lung cancers.

FHIT and FRA3B 3p14.2 allele loss are common in lung cancer and preneoplastic bronchial lesions and are associated with cancer-related FHIT cDNA splicing aberrations

We evaluated primary lung cancers, tumor cell lines, and preneoplastic bronchial lesions for molecular genetic abnormalities in the candidate tumor suppressor gene FHIT, which spans the FRA3B fragile site at 3p14.2. 3p14.2 allele loss was very frequent in 32 lung cancer cell lines [100% of small cell lung cancer and 88% of non-small cell lung cancer (NSCLC)] and 108 primary NSCLC cancers (45%), with numerous breakpoints indicating involvement of several distinct regions in the FRA3B site. 3p14 allele loss was least frequent in the adenocarcinoma subtype and occurred at the relatively late carcinoma in situ stage of preneoplastic bronchial lesions found in NSCLC patients. Homozygous deletions within the FHIT/FRA3B region were found in 6 of 135 (4.4%) thoracic cancer cell lines. Northern blot showed low or absent FHIT expression in most thoracic cancer cell lines tested, whereas reverse transcription-PCR showed that 59-62% exhibited aberrant FHIT transcripts but nearly always (93-100%) also expressing the wild-type transcripts. Aberrant transcripts included precise deletions of FHIT exons, insertion of non-FHIT sequences between exons and insertions replacing exons. Complete open reading frame single-strand conformational polymorphism analysis of 102 lung cancer cDNAs revealed only one nonsplicing mutation. Normal cells including bronchial epithelium, lung, and trachea expressed wild-type FHIT transcript and a variant transcript deleted for exon 8 but not the other aberrant transcripts, arguing against exon 8-deleted FHIT transcripts being tumor specific. Our findings support the conclusion that FHIT/FRA3B abnormalities are associated with lung cancer pathogenesis but that FHIT abnormalities differ from the types of mutations and lack of wild-type transcript found in classic tumor suppressor genes, and functional studies are needed to define the role of FHIT in thoracic tumorigenesis.

Structural and functional analysis of beta2 microglobulin abnormalities in human lung and breast cancer

The escape of tumor cells from immune recognition is a central problem in tumor immunology. Here, we examined the functional role of somatic beta 2-microglobulin (beta2m) gene mutations in human lung and breast cancers. Using single-strand conformational polymorphism (SSCP) analysis and DNA sequencing, we found mutations in the beta2m gene in 2 of 110 tested lung, colon and breast tumors and tumor cell lines. No mutations were identified in 63 breast cancer tumors, in B-lymphoblastoid cell lines or normal tissues from these or other patients. In these cell lines, beta2m protein was undetectable by Western blot analysis and there was no MHC class I on their cell surface even after treatment with interferon-gamma. Transfection of these tumor cell lines with the beta2m gene, but not addition of purified beta2m protein restored MHC expression without addition of exogenous pepticles, indicating that endogenous beta2m expression is necessary for proper intracellular MHC assembly and stabilization by endogeneous pepticles. Mutation in beta2m caused cell line H2009 to be resistant to specific lysis by influenza virus-specific CTL from HLA matched donors, and transfection of the beta2m gene restored this killing. A small cell lung cancer cell line with low class I expression and with a normal beta2m genomic sequence nonetheless also demonstrated increased class I expression after transfection of the beta2m expression vector alone, indicating that the availability of beta2m may be rate limiting for MHC assembly in this line. Our results indicate that somatic mutations or selective loss of expression of the beta2m gene in human lung cancer is rare, but can cause defective MHC class I expression and function allowing these cells to escape recognition by cytotoxic T cells.

Allele-specific chromosome 3p deletions occur at an early stage in the pathogenesis of lung carcinoma

BACKGROUND

Deletions in the short arm of chromosome 3 (3p) are present in most lung carcinomas.

OBJECTIVE

To investigate the role of these chromosome 3p deletions in the pathogenesis of non-small cell lung carcinomas.

DESIGN

Seven archival, paraffin-embedded, surgically resected lung cancer specimens were studied. Fifty precisely identified malignant and preneoplastic lesions present in bronchi, bronchioles, and alveoli were microdissected from stained slides and analyzed for allele loss using polymerase chain reaction-based assays for dinucleotide repeat polymorphisms at three chromosome 3p loci (3p14, 3p21.3, and 3p25).

SETTING

University-based medical center and affiliated hospitals.

SUBJECTS

Samples were analyzed from seven patients who underwent surgical resection with curative intent for non-small cell lung cancer and whose specimens included extensive multifocal areas of preneoplastic lesions (hyperplasia, metaplasia, dysplasia, or noninvasive cancer).

RESULTS

Lymphocytes from all seven cases were heterozygous (ie, informative) for all three microsatellites analyzed. Six (86%) of seven invasive cancers had loss of heterozygosity at one or more chromosome 3p sites. In the accompanying preneoplastic lesions, loss of heterozygosity was detected in none of two normal bronchioles, 13 (76%) of 17 hyperplasias, six (86%) of seven dysplasias, and four (100%) of four noninvasive cancers. Loss of heterozygosity was detected throughout the respiratory tract, in bronchi, bronchioles, and alveoli. In 18 (78%) of 23 preneoplastic lesions, the specific alleles lost were identical to those lost in the corresponding carcinomas. The probability of this happening by chance is 5.3 x 10(-3).

CONCLUSIONS

Deletions in the short arm of chromosome 3 occur at the earliest stage (hyperplasia) in the pathogenesis of lung cancer and involve all regions of the respiratory tract. Allele loss is highly specific, but its mechanism remains unknown. Our findings may be of considerable biologic, prognostic, and clinical significance.

Evidence for the involvement of carnitine-dependent long-chain acyltransferases in neuronal triglyceride and phospholipid fatty acid turnover

This study focuses on the potential involvement of carnitine palmitoyltransferase (CPT) on the phospholipid and triglyceride fatty acid turnover in neurons. This category of enzymes, which has been identified in several rat brain tissues, is well known for its role in modulating cellular fatty acid oxidation. Neuronal cell cultures from rat brain cortex incorporated radioactive palmitate or oleate into phospholipids and triglycerides. The largest fraction of radioactive fatty acids was recovered in phosphatidylcholine followed by triglycerides and, to a lesser extent, phosphatidylethanolamine. CPT activity measured in neuronal lysates obtained from neurons treated with 40 microM 2-tetradecylglycidic acid (TDGA) was almost completely abolished. Furthermore, between 2 and 10 microM TDGA CPT activity dropped more rapidly than between 10 and 40 microM. When the cells were pretreated with TDGA, the incorporation process of either radioactive fatty acid into triglycerides was dose-dependently suppressed. Radioactive fatty acid incorporation into phosphatidylcholine was significantly decreased in cells treated with TDGA. In contrast, phosphatidylethanolamine reacylation was essentially not affected by the CPT inhibitor. Similar results on the fatty acid incorporation into triglycerides and phospholipids were observed with neurons treated with palmitoyl-DL-aminocarnitine (PAC), a reversible CPT inhibitor, which does not consume free CoA. These effects do not seem to be the result of an inhibitory activity toward one of the steps involved in the acylation-deacylation process of triglycerides or phospholipids, as cellular lysates from TDGA-treated cells or lysates containing PAC incorporated radioactive fatty acids at rates comparable to controls. Our results suggest that CPT may be an important partner in the pathway of phospholipid and triglyceride fatty acid turnover in neurons.

Congenital adrenal hyperplasia: experience at intersex clinic, AIIMS

During 1981-88, 63 cases of female pseudohermaphroditism (FPH) were seen at the Intersex clinic at AIIMS, of whom 34 (54%) were diagnosed as due to congenital adrenal hyperplasia (CAH). Though ambiguity was present at birth in most cases, only one child was brought immediately after birth, while 14 presented after one year. Family history of affected siblings and fetal wastage was present in 10. Salt wasting symptoms were present in 13 (38.2%), evidence of early virilization in 10 (29.4%) and generalised hyperpigmentation in 7 (20.6%). Clitoromegaly was present in 30 children with labial fusion in 10 and scrotalisation of labia in 6. The urogenital opening was single in 25 (73.5%). Buccal smear was positive for sex chromatin in 19. Chromosomal pattern showed 46 XX in 33. Dyselectrolytemia was present in 16 children. Bone age was advanced in all. Adrenal hyperplasia could be documented in 3 on CT scan. All the girls were put on hydrocortisone or prednisolone, and fluodrocortisone was given only to children with salt wasting CAH. Children with CAH are being brought to medical attention much too late and investigative and therapeutic facilities are grossly inadequate. There is a need to educate primary care physicians for early case detection and provide minimum diagnostic and therapeutic facilities in regional centres.

Biosynthetic growth hormone therapy in children with growth hormone deficiency: experience at AIIMS, New Delhi

A total of 20 previously untreated children with growth hormone deficiency (GHD) were treated for one year with biosynthetic human growth hormone (hGH). The mean chronologic age was 9.43 +/- 3.52 years with a height age of 5.02 years, and bone age 9.43 +/- 3.52 (TW2-RUS) 6.42 years. The mean pretreatment growth velocity was 2.43 +/- 0.90 cm/year. Of these 14 children had complete GHD (peak GH levels less than 5 ng/ml) and 6 had partial GHD. They were treated with recombinant GH in a dose of 0.5 IU/kg/week divided into 6-7 injections per week subcutaneously at night. The mean growth velocity increased to 8.88 +/- 2.10 cm/yr at the end of 6 months and 8.00 +/- 2.21 cm/yr at 12 months. The actual gain ranged from 6-11 cm in a year. There were no local adverse reactions. One child developed vitiligo of the face and another transient hyperglycemia.

Profile of thyroid disorders in a referral centre in north India

From 1983-88, 157 patients were investigated in our clinic for thyroid disorders: 117 (75%) were hypothyroid, 10 (6%)-hyperthyroid, and 30 had euthyroid goiters. Average age of presentation of congenital hypothyroids was 4.07 years. Children with goitrous hypothyroidism (n = 19) were divided into: (i) thyroiditis: RAIU low and patchy, TMA positive: 2 children; (ii) dyshormonogenesis: RAIU high, family history positive, perchlorate discharge test positive: 2 children; (iii) iodine deficiency: RAIU high, urinary iodine low: 2 children, and (iv) cause unknown: RAIU normal or high, other investigations normal: 13 children. Ninety eight hypothyroid children without goiter were divided into 6 groups: (i) athyreosis: RAIU low, no thyroid tissue identifiable (n = 39); (ii) hypoplasia: RAIU low, gland small, in normal position (n = 7); (iii) ectopia: RAIU low, gland in ectopic position (n = 24); (iv) thyroiditis: TMA positive (n = 2); (v) iodine deficiency: low urinary iodine (n = 1); and (vi) cause unknown: RAIU and scan normal, other investigations normal and not done (n = 8). Proportionate short stature was present in 44.4% children. Twenty two children presented only with growth failure; 72% of them had dysgenetic glands. Early onset marked the group with hyperthyroidism (n = 10). Euthyroid goiter was present in 30 (19%). Hypothyroidism is still being diagnosed very late. All children with growth failure, even if proportionate, must have thyroid status evaluated.

Evaluation of thyroid function in children with undiagnosed short stature in north India

Fifty-five children with short stature were investigated for the aetiology of short stature with special reference to hypothyroidism. Clinical and laboratory parameters including anthropometry were determined to exclude any chronic systemic disorders. Thyroid function tests such as thyroxine (T4) and thyroid stimulating hormone (TSH) estimation by radioimmunoassay, radioactive iodine uptake and thyroid scan, using 131I and perchlorate discharge test, were performed. In addition, growth hormone was estimated under basal conditions and after insulin-induced hypoglycaemia. Thirty-five were boys and 20 were girls. The age at presentation in the boys was 3-12 years whereas in the girls it was 8-13 years. Forty-three of the 55 children had delayed bone age. Abnormal thyroid function was present in 25 children (45.45%). Of these, 11 (20%) had primary hypothyroidism with low or normal uptake, whereas 14 (25.45%) had glands with high uptake of 131I and elevated TSH. Three children with primary hypothyroidism had reduced growth hormone reserve. On follow-up with thyroxine, there was an increase in growth velocity in all. This study indicates that thyroid function tests should be performed routinely in children with undiagnosed short stature.