PKA/AMPK signaling in relation to adiponectin's antiproliferative effect on multiple myeloma cells.

Obesity increases the risk of developing multiple myeloma (MM). Adiponectin is a cytokine produced by adipocytes, but paradoxically decreased in obesity, that has been implicated in MM progression. Herein, we evaluated how prolonged exposure to adiponectin affected the survival of MM cells as well as putative signaling mechanisms. Adiponectin activates protein kinase A (PKA), which leads to decreased AKT activity and increased AMP-activated protein kinase (AMPK) activation. AMPK, in turn, induces cell cycle arrest and apoptosis. Adiponectin-induced apoptosis may be mediated, at least in part, by the PKA/AMPK-dependent decline in the expression of the enzyme acetyl-CoA-carboxylase (ACC), which is essential to lipogenesis. Supplementation with palmitic acid, the preliminary end product of fatty acid synthesis, rescues MM cells from adiponectin-induced apoptosis. Furthermore, 5-(tetradecyloxy)-2-furancarboxylic acid (TOFA), an ACC inhibitor, exhibited potent antiproliferative effects on MM cells that could also be inhibited by fatty acid supplementation. Thus, adiponectin's ability to reduce survival of MM cells appears to be mediated through its ability to suppress lipogenesis. Our findings suggest that PKA/AMPK pathway activators, or inhibitors of ACC, may be useful adjuvants to treat MM. Moreover, the antimyeloma effect of adiponectin supports the concept that hypoadiponectinemia, as occurs in obesity, promotes MM tumor progression.

De novo supernumerary ring chromosome 7: first report of a non-mosaic patient and review of the literature.

The present authors report the case of a 12-year-old-boy with a de novo, non-mosaic supernumerary ring chromosome 7 associated with significant developmental delay and speech difficulty. A review of the literature identified a total of 18 cases with ring chromosomes 7 who can be classified into two groups: (1) patients with a cell line that has 47 chromosomes with a small supernumerary ring chromosome 7 resulting in partial trisomy; and (2) individuals had a cell line with a large ring chromosome replacing one of the normal chromosomes 7 resulting in partial monosomy. A comparison of clinical features in the two groups of patients showed several common features such as growth and mental retardation, and facial dysmorphism, including, ear and eye anomalies. However, patients with partial trisomy have speech difficulty as a distinguishing feature, while patients with partial monosomy have skin lesions as a cardinal feature. All the published cases of ring chromosome 7, irrespective whether they are supernumerary or normal modal number, are mosaics except for one. The present subject is the first case of a de novo, non-mosaic supernumerary ring chromosome 7.

Trisomy 4 pter-q12 and monosomy of chromosome 13 pter-q12 in a male with deficiency of all blood lymphocyte populations.

A six-year-old male presented with multiple congenital anomalies, mental retardation, developmental delay, and an increased frequency of upper and lower respiratory infections and deficiency of all blood lymphocyte populations. Chromosome analysis showed an unbalanced translocation involving chromosomes 4 and 13, leading to partial trisomy for 4pter-q12 and partial monosomy for 13pter-q13 [karyotype, 46,XY,+der(4)t(4;13)(q12;q12),-13)]. The mother is the carrier of a balanced translocation involving chromosomes 4 and 13. The translocation is known to be segregating for three generations in this family. The child was found to have deficiency of all blood lymphocyte populations, but other hemopoietic lineages appeared to be normal. In addition, his fresh T cells were principally CD45RA+, CD62L+, and deficient in the Fas receptor. This deficiency of all blood lymphocyte populations may be due to an overdose of a gene or genes located in the region of chromosome 4 or a partial deficiency of a gene or genes in the region of chromosome 13 that regulate the development of the lymphocyte lineage. Since the mother contributed two copies of chromosomal region 4pter-q12 and no copy of 13pter-q12, the deficiency of all blood lymphocyte populations in our patient may be the result of either uniparental disomy or imprinting. A maternal granduncle with dissimilar dysmorphic features was not lymphopenic but was neutropenic.

Ossifying fibromyxoid tumor of soft parts: report of a case with novel cytogenetic findings.

A slowly growing tumor of the left thenar region in a 40-year-old man had the classic features of an ossifying fibromyxoid tumor of soft parts, including an incomplete shell of lamellar bone; a center composed of nodular aggregates of small spindled, oval, and stellate cells in abundant myxoid stroma; and strong expression of vimentin, S-100, and neuron-specific enolase by the tumor cells. Clonal chromosomal abnormalities included loss of a chromosome 6, extra material of unknown origin attached to the long arm of chromosome 12, and an unbalanced translocation involving the short arm of a chromosome 6 and the long arm of a chromosome 14. The karyotype was interpreted as 45,XY, der(6;14)(p10;q10),add(12)(q24.3). The chromosomal abnormalities suggest osteochondroblastic rather than neuronal or schwannian lineage.

Rapid Identification of Chromosomes Using Primed In Situ Labeling (PRINS).

Primed in situ labeling (PRINS) was introduced by Koch and colleagues (1) for the visualization of chromosome centromeres. The concept is based on the knowledge that the alpha satellite repeat monomers at the human centromeres exhibit variation among chromosomes (2), and by targeting such variation, it is possible to obtain chromosomespecific.

Duplication 8 [inv dup(8)(p12p23)] with macrocephaly.

A 10-month old female is described with inv dup(8)(p12p23) who had macrocephaly with subtle changes in facial appearance and no structural birth defects. Her findings, together with those of 37 reported cases with inv dup (8), define a syndrome that emphasizes the importance of genes on the 8p region for brain development.

Acute myeloid leukemia associated with hemophagocytic syndrome and t(4;7)(q21;q36).

Hemophagocytic syndrome (HS) is a histiocytic reactive process often associated with infections and/or malignancies. Clonal karyotypic abnormalities have been the hallmark of several hematological malignancies and have been shown to be of clinical significance in terms of both diagnosis and prognosis. While there are limited reports of both clonal and nonclonal abnormalities in HS, their clinical significance has not been established. Detection of such clonal abnormalities, as seen in some cases of HS, may indicate the presence of an occult malignant process, even when there is no microscopic evidence of a hematological malignancy. We report a case of HS in a child with clonal t(4;7)(q21;q36) which later progressed to acute myeloid leukemia (AML) with further clonal evolution. Our case strengthens the argument that cytogenetic studies in HS may be important in identifying the underlying occult malignant process.

Patent ductus arteriosus and microdeletion 22q11 in a patient with Klinefelter syndrome.

We describe an uncommon association of deletion 22q11 in a patient with Klinefelter syndrome. Even though congenital heart defects (CHD) are not associated with Klinefelter syndrome, further investigation of this patient with patent ductus arteriosus showed a microdeletion of chromosome 22q11.2. While this finding may be coincidental, it is important to further evaluate patients when the clinical features are suggestive of a secondary abnormality.

Fanconi anemia: myelodysplasia as a predictor of outcome.

The adverse potential of the development of myelodysplastic syndrome (MDS) in Fanconi anemia (FA) was examined in a retrospective study of 41 FA patients who had bone marrow morphology and chromosomes reviewed by a single group. Thirty-three patients had adequate cytogenetic studies, and 16 (48%) had one or more abnormal studies: nine initially, and seven more on follow-up. Cytogenetic clonal variation was frequent, including disappearance of clones, clonal evolution, and appearance of new clones. The estimated five-year survival with a cytogenetic clone is 0.40, compared to 0.94 without a clone. Morphologic myelodysplasia (MDS), independent of a cytogenetic clone, was found in 13/41 patients (32%). The estimated five-year survival with MDS is 0.09, versus 0.92 without MDS. Leukemia developed in three patients whose initial cytogenetic clones prior to leukemia were t(1;18), t(5;22) and monosomy 7; the one with t(1;18) also had MDS. Our results focus on marrow morphology, and suggest that morphologic MDS may be more important than classical cytogenetics in prediction of an adverse outcome.

Trisomy 5p. A case report and review.

Trisomy 5p is a clinically discernable syndrome with characteristic clinical features. To date more than 40 patients with trisomy for various regions of short arm of chromosome 5 have been reported. Here we report a case with complete trisomy 5p and present a review of the literature.

Chromosome duplications and deletions and their mechanisms of origin.

Duplications and deletions of the same gene loci or chromosome regions are known to produce different clinical manifestations and are significant factors in human morbidity and mortality. Extensive cytogenetic and molecular cytogenetic studies with cosmid and YAC probes in two patients with unique mosaicism for reciprocal duplication-deletion allowed us to further understand the origin of these abnormalities. The first patient's mosaic karyotype was 46,XX, inv dup(11) (q23q13)/46,XX,del(11)(q13q23). The second patient had a 46,XY,dup(7)(p11.2p13)/46,XY,del(7)(p11.2p13)/46,XY karyotype. Fluorescence in situ hybridization studies on the first patient placed the two breakpoints near the folate-sensitive fragile sites FRA11A and FRA11B. The presence of repeated sequences responsible for these fragile sites may have been involved in the patient's duplication-deletion. Our investigation leads us to conclude that, in addition to known mechanisms (such as unequal crossovers between homologs, unequal sister chromatid exchanges, excision of intrachromatid loops, and meiotic recombination within a single chromatid), duplication-deletion can also arise by the formation of an overlying loop followed by an uneven crossover at the level of the DNA strand.

Validation of primed in situ labeling (PRINS) for interphase analysis: comparative studies with conventional fluorescence in situ hybridization and chromosome analyses.

Primed in situ labeling (PRINS) is a rapidly developing new technology with wide ranging clinical applications. To assess the sensitivity, specificity, and accuracy of PRINS, we carried out a retrospective study on cultured bone marrow cells to detect aneuploidy for chromosomes 7, 8, and 12. The results were then compared to the results of previous fluorescence in situ hybridization (FISH) and chromosome analyses (CA). In patients who showed aneuploidy with CA, both FISH and PRINS confirmed the aneuploidy in interphase cells. FISH and PRINS also showed excellent correlation with conventional cytogenetic analysis for the detection of mosaic aneuploidies. However, both FISH and PRINS showed significantly higher sensitivity in the detection of abnormal clones compared to CA. In 9 of the 17 cases, there were no significant differences in the detection rates between the two methods. Based on our studies, we conclude that PRINS is as sensitive as FISH in most cases for aneuploidy detection; and that PRINS, like FISH, is more sensitive than conventional CA for aneuploidy detection.

Infant with midline thoracoabdominal schisis and limb defects.

An infant presented with multiple congenital anomalies including a midline thoracoabdominal defect, absence of the sternum, ectopia cordis, right diaphragmatic hernia, right anophthalmia, left microphthalmia, incomplete bilateral cleft lip, and various limb defects including ectrodactyly of the right hand and left foot, and phocomelia of the right lower extremity. The infant expired soon after birth. The radiological findings included absence of the sternum, 11 right-sided ribs, absence of the middle third of the right clavicle, opaque right hemithorax, hypoplastic right tibia, absent right fibula and foot, and ectrodactyly of the right hand and left foot. In addition, the autopsy revealed two distinct diaphragmatic defects, an anterior midline defect of the diaphragm beneath the ectopic heart, and a large Bochdalek hernia, with abdominal contents in the chest. Our case has overlapping features with conditions such as thoracoabdominal syndrome, pentalogy of Cantrell, and limb-body wall complex, but the concurrence of midline body wall defect and ectrodactyly has not been described previously.

Simultaneous adrenocortical carcinoma and ganglioneuroblastoma in a child with Turner syndrome and germline p53 mutation.

The predisposition to malignancy that is dominantly inherited in Li-Fraumeni syndrome is associated with germline mutations of the tumour suppressor gene p53. Although second malignant neoplasms have been described in children with p53 mutations, the synchronous occurrence of two embryologically different tumours in these children has not been reported. A 20 month old girl with failure to thrive and congenital heart defects was found to have unilateral adrenal masses which, at surgical removal, proved to be an adrenocortical carcinoma and a ganglioneuroblastoma. Further investigation showed a germline p53 mutation and Turner syndrome. It remains to be determined what effect the 45,X chromosomal complement may have on the expression of neoplasms seen in patients with p53 germline mutations.

Most Jacobsen syndrome deletion breakpoints occur distal to FRA11B.

Recent studies have identified a (CCG)n repeat in the 5' untranslated region of the CBL2 protooncogene (11q23.3) and have demonstrated that expansion of this repeat causes expression of the folate-sensitive fragile site FRA11B. It has also been demonstrated that FRA11B is the site of breakage in some cases of Jacobsen syndrome (JS) involving terminal deletions of chromosome 11q. We report on 2 patients with JS and a 46,XX,del(11)(q23.3) karyotype. In both cases, microsatellite and fluorescence in situ hybridization analyses indicated that the deletion breakpoint was approximately 1.5-3 Mb telomeric to FRA11B. There was no evidence of expansion of the CBL2 (CCG)n repeat in the parents of either patient. The deleted chromosome was of paternal origin in both cases, although it was of maternal origin in the cases reported to be caused by FRA11B. These findings and those in previously reported patients suggest that the breakpoint for most 11q deletions in JS patients is telomeric to FRA11B, which raises the possibility that there may be other fragile sites in 11q23.3 in addition to FRA11B. These findings also support previous evidence that there may be a propensity for breakpoints to differ depending on the parental origin of the deleted chromosome.

Rapid identification of marker chromosomes using primed in situ labeling (PRINS).

Primed in situ labeling (PRINS) is a relatively new technology with wide-ranging applications in clinical cytogenetics. Using PRINS, we have identified the chromosomal origin of marker chromosomes in three patients. In the first patient with primary amenorrhea, we were able to confirm the marker chromosome as originating from an X. In the second (prenatal) case, PRINS allowed us to determine rapidly the origin of the marker as a Y chromosome. In the third patient with minor anomalies, the marker was identified as derived from a chromosome 18. In all three cases, application of PRINS permitted us to characterize the marker chromosomes within 1 hour after the slides were prepared. The methodology is simple, has added advantages over conventional fluorescence in situ hybridization (FISH), and can be used as a viable and effective alternative to FISH in clinical cytogenetic diagnosis.

Down syndrome with biparental inheritance of der(14q21q) and maternally derived trisomy 21: confirmation by fluorescent in situ hybridization and microsatellite polymorphism analysis.

Individuals with translocation Down syndrome (DS) often inherit the rearranged chromosome from a carrier parent. DS due to inheritance of one Robertsonian or derivative (14q21q) from one parent and a second der(14q21q) in addition to a free chromosome 21 from the other parent are rarely documented in liveborn infants. Presented here is such a propositus with DS and with a unique karyotype 45,XY,der(14;21) (p11.1;p11.1)pat,der(14;21)(p11.1;q11.1)mat, +21mat. Using conventional chromosome heteromorphisms, fluorescent in situ hybridization (FISH), and microsatellite polymorphism analyses, we established the biparental origin of the 2 der(14q21q) and the maternal origin of the extra chromosome 21 in the patient. A combination of both cytogenetic and molecular genetic techniques also enabled us to show that the 2 der(14q21q) were not identical by descent and hence the parents were nonconsanguineous. It has been a well-established fact that mothers with Robertsonian translocations have higher risk for nondisjunction than do carrier fathers. Our case, wherein the nondisjunctional event occurred in the mother, even though both parents are carriers of a 14;21 Robertsonian translocation, is yet another example of this.

Discordant direct and culture results following chorionic villus sampling and the diagnosis of a third cell line in the fetus.

We report a case of discordant non-mosaic karyotypes following chorionic villus sampling (CVS). A 45,XX,der(21;21)(q10;q10) karyotype was found on direct preparation of cytotrophoblasts and 46,XX was found on long-term culture of mesenchymal core cells. Analysis of amniotic fluid cells and fetal tissue revealed a third karyotype: 46,XX,+21,der(21;21)(q10;q10). Had only culture analysis been performed, follow-up studies might not have been undertaken. This case demonstrates the importance of direct CVS preparation in helping to identify fetal abnormalities, and the need for follow-up of discordant CVS results.

Clinical applications of primed in situ labelling (PRINS) rapid identification of a marker chromosome in a fetus.

Marker chromosomes pose a serious problem in clinical cytogenetic diagnosis since the conventional banding analyses are often not useful in identifying their origin or composition. In the absence of information, counseling as to the clinical significance and prognosis is difficult, especially in prenatal diagnosis. With the introduction of fluorescence in situ hybridization (FISH) marker identification has became feasible. However, FISH is relatively time-consuming and expensive. In an effort to overcome these disadvantages, we have used primed in situ labelling (PRINS) technique as an alternative. Presented here is one case in which PRINS was useful in rapidly identifying the origin of a marker chromosome detected on amniotic fluid chromosome analysis. Based on our experience with this case and others, we propose that PRINS can become a viable and cost effective alternative to FISH and is as reliable as FISH in terms of accuracy, specificity, and sensitivity.