Refined mapping of allele loss at chromosome 10q23-26 in prostate cancer

Chromosome 10 abnormality predicts prognosis of neuroblastoma patients with bone marrow metastasis

BACKGROUND

Neuroblastoma (NB) is the most common extracranial solid tumor in children. It is known for high heterogeneity and concealed onset. In recent years, the mechanism of its occurrence and development has been gradually revealed. The purpose of this study is to summarize the clinical characteristics of children with NB and abnormal chromosome 10, and to investigate the relationship between the number and structure of chromosome 10 abnormalities and NB prognosis.

METHODS

Chromosome G-banding was used at the time of diagnosis to evaluate the genetics of chromosomes in patients with NB and track their clinical characteristics and prognosis. All participants were diagnosed with NB in the Medical Oncology Department of the Beijing Children's Hospital from May 2015 to December 2018 and were followed up with for at least 1 year.

RESULTS

Of all 150 patients with bone marrow metastases, 42 were clearly diagnosed with chromosomal abnormalities. Thirteen patients showed abnormalities in chromosome 10, and chromosome 10 was the most commonly missing chromosome. These 13 patients had higher LDH and lower OS and EFS than children with chromosomal abnormalities who did not have an abnormality in chromosome 10. Eight patients had both MYCN amplification and 1p36 deletion. Two patients had optic nerve damage and no vision, and one patient had left supraorbital metastases 5 months after treatment.

CONCLUSIONS

The results indicated that chromosome 10 might be a new prognostic marker for NB. MYCN amplification and 1p36 deletion may be related to chromosome 10 abnormalities in NB. Additionally, NB patients with abnormal chromosome 10 were prone to orbital metastases.

The Effect of Quercetin Nanosuspension on Prostate Cancer Cell Line LNCaP via Hedgehog Signaling Pathway

Background

Prostate cancer (PCa) is the second leading cause of cancer death in American population. In this manner, novel therapeutic approaches for identification of therapeutic targets for PCa has significant clinical implications. Quercetin is a potent cancer therapeutic agent and dietary antioxidant present in fruit and vegetables.

Methods

To investigate the underlying mechanism by which the PCa was regulated, nanoparticles of quercetin were administrated to cells. For in vitro experiments, human PCa cell line LNCaP were involved. Cell viability assay and quantitative RT-PCR (qRT-PCR) for hedgehog signaling pathway genes were used to determine the key signaling pathway regulated for PCa progression.

Results

The cell viability gradually decreased with increased concentration of quercetin nanoparticles. At 48 h, 40 mM concentration of quercetin treatment showed near 50% of viable cells. Quercetin nanoparticles upregulates Su(Fu) mRNA expressions and downregulates gli mRNA expressions in the LNCaP cells.

Conclusion

The results showed that the hedgehog signaling targeted inhibition may have important implications of PCa therapeutics. Additionally, the outcomes provided new mechanistic basis for further examination of quercetin nanoparticles to discover potential treatment strategies and new targets for PCa inhibition.

C10orf116 Gene Copy Number Loss in Prostate Cancer: Clinicopathological Correlations and Prognostic Significance

Background

Prostate cancer (PCa) is the second most commonly diagnosed cancer in males worldwide. This study aimed to identify differentially expressed genes and to investigate the potential correlation between gene abnormalities and clinical features in PCa to evaluate disease progression and prognosis.

Material/Methods

A total of 4 independent microarrays of PCa patients from the Oncomine database were used to identify differences in expression of genes contributing to cancer progression. Quantitative real-time polymerase chain reaction (RT-qPCR) analysis was used to evaluate the mRNA expression of the target in human prostate cancer cells. To explore the relationship between the DNA copy number alteration and mRNA expression changes, dataset containing copy number alteration, DNA methylation, and gene expression in PCa were obtained from the cBioPortal online platform (n=273).

Results

We identified 40 genes that were significantly dysregulated in PCa from 4 independent microarrays. Among these, 3 genes showed a consistent change of over 2-fold in the 4 microarrays. The mRNA expression of C10orf116 showed consistent expression in prostate cancer cells compared with that in prostate gland cells as assessed by RT-qPCR. Moreover, C10orf116 loss was associated with poor distant relapse-free survival (DFS) by analyzing data of 273 PCa patients, but it was not identified as an independent prognostic risk factor for DFS. In addition, we found that C10orf116 loss was associated with higher pathological stage, higher clinical stage, and lymph node metastasis in PCa, and that C10orf116 copy number was highly correlated with PTEN copy number and mRNA expression.

Conclusions

As a predictive indicator, C10orf116 loss contributes to our understating of the biology of aggressive changes in PCa and also helps evaluate the prognosis of patients.

Exploring prostate cancer genome reveals simultaneous losses of PTEN, FAS and PAPSS2 in patients with PSA recurrence after radical prostatectomy

The multifocal nature of prostate cancer (PCa) creates a challenge to patients' outcome prediction and their clinical management. An approach that scrutinizes every cancer focus is needed in order to generate a comprehensive evaluation of the disease, and by correlating to patients' clinico-pathological information, specific prognostic biomarker can be identified. Our study utilized the Affymetrix SNP 6.0 Genome-wide assay to investigate forty-three fresh frozen PCa tissue foci from twenty-three patients. With a long clinical follow-up period that ranged from 2.0-9.7 (mean 5.4) years, copy number variation (CNV) data was evaluated for association with patients' PSA status during follow-up. From our results, the loss of unique genes on 10q23.31 and 10q23.2-10q23.31 were identified to be significantly associated to PSA recurrence (p < 0.05). The implication of PTEN and FAS loss (10q23.31) support previous reports due to their critical roles in prostate carcinogenesis. Furthermore, we hypothesize that the PAPSS2 gene (10q23.2-10q23.31) may be functionally relevant in post-operative PSA recurrence because of its reported role in androgen biosynthesis. It is suggestive that the loss of the susceptible region on chromosome 10q, which implicates PTEN, FAS and PAPSS2 may serve as genetic predictors of PSA recurrence after radical prostatectomy.

Prognostic prostate tissue biomarkers of potential clinical use

In prostate biopsies and in prostatectomy specimens, the Gleason score remains the strongest prognosticator of prostate cancer progression, in addition to serum PSA level and DRE findings, in spite of numerous potential biomarkers discovered during the last few decades. Inter- and intratumoural heterogeneity may have limited the employment of tissue biomarkers on prostate biopsies. Nevertheless, the monoclonality of morphologically heterogeneous (Gleason score 7) tumour foci would suggest that genetic biomarkers, arising early in prostate carcinogenesis, may overcome issues related to intratumoural heterogeneity. In spite of the above limitations, a few biomarkers including the proliferation marker Ki-67 and genetic markers such as c-MYC and PTEN have consistently shown their independent prognostic impact both for biochemical recurrence and for clinical outcome parameters such as metastatic disease or prostate-specific mortality. The routine application of biomarkers requiring immunostaining (e.g. Ki-67) has particularly been hindered by the lack of standardized protocols for processing and scoring, while the application of fluorescence in situ hybridization (FISH) technology is considered more labour intensive but better standardized. Future steps to enhance the uptake of prostate tissue biomarkers should be focused on prospective studies, particularly on prostate biopsy specimens, using protocols that are highly standardized for the processing and scoring of the biomarkers. A few recently developed RNA-based test signatures may provide an alternative to FISH or immunohistochemistry-based tests.

Transforming acidic coiled-coil proteins (TACCs) in human cancer

Fine-tuned regulation of the centrosome/microtubule dynamics during mitosis is essential for faithful cell division. Thus, it is not surprising that deregulations in this dynamic network can contribute to genomic instability and tumorigenesis. Indeed, centrosome loss or amplification, spindle multipolarity and aneuploidy are often found in a majority of human malignancies, suggesting that defects in centrosome and associated microtubules may be directly or indirectly linked to cancer. Therefore, future research to identify and characterize genes required for the normal centrosome function and microtubule dynamics may help us gain insight into the complexity of cancer, and further provide new avenues for prognostic, diagnostics and therapeutic interventions. Members of the transforming acidic coiled-coil proteins (TACCs) family are emerging as important players of centrosome and microtubule-associated functions. Growing evidence indicates that TACCs are involved in the progression of certain solid tumors. Here, we will discuss our current understanding of the biological function of TACCs, their relevance to human cancer and possible implications for cancer management.

The sonic hedgehog-GLI1 signaling pathway in brain tumor development

INTRODUCTION

The sonic hedgehog (Shh) pathway is a regulatory network involved in development and cancer. Proteins like Ptch, SMO, and Gli are central to the Shh pathway. Other proteins like HHIP, SUFU, Bmi-1, Cyclin D2, Plakoglobin, PAX6, Nkx2.2, and SFRP1 are not so well understood in Shh regulation as Gli-1 downstream target genes.

AREAS COVERED

In this review we try to explain the Shh pathway components and their role in development and cancer, mainly of the brain. A summary of each of the proteins is presented together with an overview of their involvement in cancer.

EXPERT OPINION

Genetic alterations of the Shh pathway have been detected in cancer stem cells, a subgroup of tumor cells implicated in the origin and maintenance of tumors, being responsible for cancer recurrence and chemotherapy resistance. Cancer stem cells constitute a novel target for biomedical researchers. Specifically, the Shh pathway is being explored as a new opportunity for targeted therapies against tumors. Therefore, a better knowledge of every of the regulators of the Shh pathway is needed.

Prostate cancer and Hedgehog signalling pathway

The Hedgehog (Hh) family of intercellular signalling proteins have come to be recognised as key mediators in many fundamental processes in embryonic development. Their activities are central to the growth, patterning and morphogenesis of many different regions within the bodies of vertebrates. In some contexts, Hh signals act as morphogens in the dose-dependent induction of distinct cell fates within a target field, in others as mitogens in the regulation of cell proliferation or as inducing factors controlling the form of a developing organ. These diverse functions of Hh proteins raise many intriguing questions about their mode of action. Various studies have now demonstrated the function of Hh signalling in the control of cell proliferation, especially for stem cells and stem-like progenitors. Abnormal activation of the Hh pathway has been demonstrated in a variety of human tumours. Hh pathway activity in these tumours is required for cancer cell proliferation and tumour growth. Recent studies have uncovered the role for Hh signalling in advanced prostate cancer and demonstrated that autocrine signalling by tumour cells is required for proliferation, viability and invasive behaviour. Thus, Hh signalling represents a novel pathway in prostate cancer that offers opportunities for prognostic biomarker development, drug targeting and therapeutic response monitoring.

Determining risk of biochemical recurrence in prostate cancer by immunohistochemical detection of PTEN expression and Akt activation

PURPOSE

A considerable fraction of patients who undergo radical prostatectomy as treatment for primary prostate cancer experience biochemical recurrence detected by elevated serum levels of prostate-specific antigen. In this study, we investigate whether loss of expression of the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and the phosphorylated form of the cell survival protein Akt (pAkt) predicts biochemical recurrence.

EXPERIMENTAL DESIGN

Expression of PTEN and pAkt was detected by immunohistochemistry in paraffin-embedded prostate cancer tissue obtained from men undergoing radical prostatectomy. Outcome was determined by 60-month follow-up determining serum prostate-specific antigen levels.

RESULTS

By itself, PTEN was not a good predictor of biochemical recurrence; however, in combination with pAkt, it was a better predictor of the risk of biochemical recurrence compared with pAkt alone. Ninety percent of all cases with high pAkt and negative PTEN were recurrent whereas 88.2% of those with low pAkt and positive PTEN were nonrecurrent. In addition, high Gleason scores resulted in reduced protection from decreased pAkt and increased PTEN. By univariate logistic regression, pAkt alone gives an area under the receiver-operator characteristic curve of 0.82 whereas the area under the receiver-operator characteristic curve for the combination of PTEN, pAkt, and Gleason based on a stepwise selection model is 0.89, indicating excellent discrimination.

CONCLUSIONS

Our results indicate that loss of PTEN expression, together with increased Akt phosphorylation and Gleason score, is of significant predictive value for determining, at the time of prostatectomy, the risk of biochemical recurrence.

Loss of heterozygosity and microsatellite instability on chromosome arm 10q in neuroblastoma

Tumor suppressor genes can be inactivated by various mechanisms, including promoter hypermethylation and loss of heterozygosity. We screened the 10q locus for loss of heterozygosity and the promoter methylation status of PTEN, MGMT, MXI1, and FGFR2 in neuroblastic tumors and neuroblastoma cell lines. Expression of these genes in cell lines was analyzed with reverse transcriptase-polymerase chain reaction. Loss of heterozygosity at 10q was detected in 18% of tumors and microsatellite instability in 14%. Promoter hypermethylation of MGMT appeared in 8% of tumors and 25% of cell lines. Correlation between methylation status and lack of expression was evident for PTEN, FGFR2, and MXI1 and was less clear for MGMT. No associations between these alterations and MYCN amplification, 1p deletion, or aggressive tumor histology could be demonstrated, singly or in combination. These data suggest that 10q alterations might be implicated in the development of a small number of neuroblastomas.

Allelic imbalance and biochemical outcome after radical prostatectomy

OBJECTIVE

To compare the incidence of allelic imbalance (AI) in men with rapid disease progression with those who remained disease free after radical prostatectomy, with the aim of identifying genetic markers to predict prognosis and guide further treatment.

PATIENTS AND METHODS

Tumour and normal DNA were extracted from two matched groups of 31 men with extracapsular node-negative (pT3N0) prostate cancer who had undergone radical prostatectomy. One group comprised men who developed biochemical recurrence within 2 years of surgery and one group were prostate-specific antigen (PSA) free for at least 3 years. Men were matched for Gleason grade, preoperative PSA and pathological stage. Analysis was performed by genotyping.

RESULTS

Allelic imbalance was analysed using 30 markers, and was seen in at least one marker in 57 (92%) of the cases. Deletion at marker D10S211 (10p12.1) was significantly more common in the relapse group than the non-relapse group (35 vs 5%, P=0.03).

CONCLUSIONS

This study demonstrates significant association between AI on chromosome 10 and biochemical progression after radical prostatectomy.

Molecular changes in prostatic cancer

Prostate cancer is one of the most commonly diagnosed and potentially devastating cancers in men, throughout the world. However, the clinical manifestation of this disease varies greatly, from indolent tumours, requiring little or no treatment, to those aggressive cancers which require radical therapies. Prostate cancer, like all other cancers, develops and progresses as a consequence of an accumulation of genetic changes. While several putative genes have been isolated for the development of breast, ovarian and colon cancer, the aetiology and pathogenesis of prostate cancer remains poorly understood. In this review, we discuss important genetic markers in early, metastatic and hormone refractory prostate cancer which may, in the future, be used as markers for diagnosis and prognosis, as well as targets for therapeutic intervention.

Activation of the hedgehog pathway in advanced prostate cancer

BACKGROUND

The hedgehog pathway plays a critical role in the development of prostate. However, the role of the hedgehog pathway in prostate cancer is not clear. Prostate cancer is the second most prevalent cause of cancer death in American men. Therefore, identification of novel therapeutic targets for prostate cancer has significant clinical implications.

RESULTS

Here we report that activation of the hedgehog pathway occurs frequently in advanced human prostate cancer. We find that high levels of hedgehog target genes, PTCH1 and hedgehog-interacting protein (HIP), are detected in over 70% of prostate tumors with Gleason scores 8-10, but in only 22% of tumors with Gleason scores 3-6. Furthermore, four available metastatic tumors all have high expression of PTCH1 and HIP. To identify the mechanism of the hedgehog signaling activation, we examine expression of Su(Fu) protein, a negative regulator of the hedgehog pathway. We find that Su(Fu) protein is undetectable in 11 of 27 PTCH1 positive tumors, two of them contain somatic loss-of-function mutations of Su(Fu). Furthermore, expression of sonic hedgehog protein is detected in majority of PTCH1 positive tumors (24 out of 27). High levels of hedgehog target genes are also detected in four prostate cancer cell lines (TSU, DU145, LN-Cap and PC3). We demonstrate that inhibition of hedgehog signaling by smoothened antagonist, cyclopamine, suppresses hedgehog signaling, down-regulates cell invasiveness and induces apoptosis. In addition, cancer cells expressing Gli1 under the CMV promoter are resistant to cyclopamine-mediated apoptosis. All these data suggest a significant role of the hedgehog pathway for cellular functions of prostate cancer cells.

CONCLUSION

Our data indicate that activation of the hedgehog pathway, through loss of Su(Fu) or overexpression of sonic hedgehog, may involve tumor progression and metastases of prostate cancer. Thus, targeted inhibition of hedgehog signaling may have significant implications of prostate cancer therapeutics.

Accuracy of an array comparative genomic hybridization (CGH) technique in detecting DNA copy number aberrations: comparison with conventional CGH and loss of heterozygosity analysis in prostate cancer

Although genomic DNA microarray (array comparative genomic hybridization [CGH]) technique is a rapid and powerful diagnostic tool for the comprehensive analysis of detailed chromosomal alterations of DNA copy numbers, its accuracy has not been well demonstrated. To clarify the accuracy of this technique, we applied array CGH spotted with 283 specific genes to 11 clinical prostate cancers, and the results were compared with comparative genomic hybridization (conventional CGH) and loss of heterozygosity (LOH) analysis using microsatellite DNA markers. The overall rate of correspondence between array CGH and conventional CGH with respect to the loss of DNA sequences was 94.5%. When the results of both CGH techniques were compared with those of LOH analysis, the correspondence rate of array CGH was significantly higher than that of conventional CGH (93.4% vs. 72.2%, P<0.05). In conclusion, the accuracy of array CGH was higher than that of conventional CGH in detecting losses of the DNA sequences. Array CGH is shown to be a promising tool for screening to identify unknown genes involved in tumorigenesis in prostate cancer.

Loss of a small region around the PTEN locus is a major chromosome 10 alteration in prostate cancer xenografts and cell lines

We examined 11 prostate cancer xenografts and 4 cell lines for chromosome 10 alterations. Conventional comparative genomic hybridization (CGH) and array-based CGH revealed a pattern of loss of distal 10p, gain of proximal 10p and 10q, and loss of distal 10q. In addition, array CGH identified 2 high-level amplifications in the cell line PC3, homozygous deletions of PTEN in PC3 and in the xenografts PCEW, PC133, and PC324, and small single- or double-copy deletions around PTEN in PCEW, PC82, PC324, PC346, and LNCaP. Allelotype analysis confirmed all 10p losses, 5 of 6 large 10q losses, the homozygous deletions, and the small regions of one copy loss. MXI1, DMBT1, and KLF6 were excluded as important tumor-suppressor genes. The sizes of homozygous deletions around PTEN ranged from 1.2 Mbp (PC133) to <30 kbp (PTEN exon 5 in PC295). The regions of small single- or double-copy loss around PTEN were all less than 4.5 Mbp. The loss of 1 or 2 copies of PTEN was always accompanied by loss of the distal flanking gene FLJ11218 and, in most cases, by loss of the proximal flanking genes MINPP1, PAPSS2, and FLJ14600. Furthermore, differential expression was detected for FLJ11218 and PAPSS2. Complete deletion or inactivating mutation of PAPSS2 was found in at least 3 samples. In addition to 4 homozygous deletions, 1 missense mutation was detected in FLJ11218. In conclusion, our data provide evidence that loss of a small region around PTEN is the major chromosome 10 alteration in prostate cancer xenografts and cell lines. In some of the samples, PTEN inactivation was accompanied by loss of 1 MINPP1 allele, loss of 1 copy, mutation, or low expression of PAPSS2, and most frequently by loss of 1 or 2 copies or low expression of FLJ11218.

Homozygous deletion and expression of PTEN and DMBT1 in human primary neuroblastoma and cell lines

Neuroblastoma is the most common pediatric solid tumor. Although many allelic imbalances have been described, a bona fide tumor suppressor gene for this disease has not been found yet. In our study, we analyzed 2 genes, PTEN and DMBT1, mapping 10q23.31 and 10q25.3-26.1, respectively, which have been found frequently altered in other kinds of neoplasms. We screened both genes for homozygous deletions in 45 primary neuroblastic tumors and 12 neuroblastoma cell lines. Expression of these genes in cell lines was assessed by RT-PCR analysis. We could detect 2 of 41 (5%) primary tumors harboring PTEN homozygous deletions. Three of 41 (7%) primary tumors and 2 of 12 cell lines presented homozygous losses at the g14 STS on the DMBT1 locus. All cell lines analyzed expressed PTEN, but lack of DMBT1 mRNA expression was detected in 2 of them. We tried to see whether epigenetic mechanisms, such as aberrant promoter hypermethylation, had any role in DMBT1 silencing. The 2 cell lines lacking DMBT1 expression were treated with 5-aza-2'-deoxycytidine; DMBT1 expression was restored in only one of them (MC-IXC). From our work, we can conclude that PTEN and DMBT1 seem to contribute to the development of a small fraction of neuroblastomas, and that promoter hypermethylation might have a role in DMBT1 gene silencing.

Clinical, cytogenetic, and molecular observations in a patient with Pallister-Killian-syndrome with an unusual karyotype

Pallister-Killian syndrome is a clinically recognizable syndrome, usually due to a tissue-limited mosaicism for a supernumary 12p isochromosome (i12p). Here we report an unusual case with tetrasomy/trisomy/disomy 12p mosaic in fibroblasts and trisomy/disomy 12p mosaic in lymphocytes. The tetrasomy 12p was due to an i12p, the trisomy 12p to a single 12p marker. Both marker chromosomes were investigated with conventional cytogenetic techniques and fluorescent in situ hybridization (FISH). Stability under culturing conditions was studied. DNA-analysis revealed prezygotic maternal origin of the extra 12p material. Clinically, the patient seems to have less retardation than most patients with Pallister-Killian syndrome.

Refined physical map of the human PAX2/HOX11/NFKB2 cancer gene region at 10q24 and relocalization of the HPV6AI1 viral integration site to 14q13.3-q21.1

BACKGROUND

Chromosome band 10q24 is a gene-rich domain and host to a number of cancer, developmental, and neurological genes. Recurring translocations, deletions and mutations involving this chromosome band have been observed in different human cancers and other disease conditions, but the precise identification of breakpoint sites, and detailed characterization of the genetic basis and mechanisms which underlie many of these rearrangements has yet to be resolved. Towards this end it is vital to establish a definitive genetic map of this region, which to date has shown considerable volatility through time in published works of scientific journals, within different builds of the same international genomic database, and across the differently constructed databases.

RESULTS

Using a combination of chromosome and interphase fluorescent in situ hybridization (FISH), BAC end-sequencing and genomic database analysis we present a physical map showing that the order and chromosomal orientation of selected genes within 10q24 is CEN-CYP2C9-PAX2-HOX11-NFKB2-TEL. Our analysis has resolved the orientation of an otherwise dynamically evolving assembly of larger contigs upstream of this region, and in so doing verifies the order and orientation of a further 9 cancer-related genes and GOT1. This study further shows that the previously reported human papillomavirus type 6a DNA integration site HPV6AI1 does not map to 10q24, but that it maps at the interface of chromosome bands 14q13.3-q21.1.

CONCLUSIONS

This revised map will allow more precise localization of chromosome rearrangements involving chromosome band 10q24, and will serve as a useful baseline to better understand the molecular aetiology of chromosomal instability in this region. In particular, the relocation of HPV6AI1 is important to report because this HPV6a integration site, originally isolated from a tonsillar carcinoma, was shown to be rearranged in other HPV6a-related malignancies, including 2 of 25 genital condylomas, and 2 of 7 head and neck tumors tested. Our finding shifts the focus of this genomic interest from 10q24 to the chromosome 14 site.

Molecular cloning, genomic structure and interactions of the putative breast tumor suppressor TACC2

The human transforming acidic coiled-coil 2 (TACC2) gene has been suggested recently to be a putative breast tumor suppressor. Now we can report the cloning of full length TACC2 cDNAs corresponding to the major isoforms expressed during development. The TACC2 gene is encoded by 23 exons, and spans 255 kb of chromosome 10q26. In breast cancer cell lines, TACC2 is expressed as a 120 kDa protein corresponding to the major transcript expressed in the mammary gland. Although only slight differences in the expression of TACC2 in normal versus breast tumors were observed, overexpression of TACC2 can alter the in vitro cellular dynamics of some breast cancer cell lines. Significantly, we demonstrate that TACC2 interacts with GAS41 and the SWI/SNF chromatin remodeling complex. This suggests that defects in TACC2 expression may affect gene regulation, thus contributing to the pathogenesis of some tumors.