Lower expression of ATM and gene deletion is more frequent in adrenocortical carcinomas than adrenocortical adenomas

Ataxia telangiectasia mutated germline pathogenic variant in adrenocortical carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare malignancy arising from the adrenal cortex. ACC carries a dismal prognosis and surgery offers the only chance for a cure. Germline pathogenic variants among certain oncogenes have been implicated in ACC. Here, we report the first case of ACC in a patient with a pathogenic variant in the Ataxia Telangiectasia Mutated (ATM) gene.

PATIENTS AND METHODS

A 56-year-old Caucasian woman with biopsy proven ACC deemed unresectable and treated with etoposide, doxorubicin and cisplatin (EDP), and mitotane presented to our institution for evaluation. The tumor specimen was examined pathologically, and genetic analyses were performed on the tumor and germline using next-generation sequencing.

RESULTS

Pathologic evaluation revealed an 18.0 × 14.0 × 9.0 cm low-grade ACC with tumor free resection margins. Immunohistochemistry stained for inhibin, melan-A, and chromogranin. ClinOmics analysis revealed a germline pathogenic deletion mutation of one nucleotide in ATM is denoted as c.1215delT at the cDNA level and p.Asn405LysfsX15 (N405KfsX15) at the protein level. Genomic analysis of the tumor showed loss of heterozygosity (LOH) of chromosome 11 on which the ATM resides.

CONCLUSION

ACC is an aggressive malignancy for which surgical resection currently offers the only curative option. Here we report a heterozygous loss-of-function mutation in germline DNA and LOH of ATM in tumor in an ACC patient, a classic two-hit scenario in a well-known cancer suppresser gene, suggesting a pathogenic role of the ATM gene in certain ACC cases.

Expression of DNA repair genes in oral squamous cell carcinoma using reverse transcription-quantitative polymerase chain reaction

OBJECTIVE

The aim of this study was to evaluate the expression of DNA repair genes in cases of oral squamous cell carcinoma (OSCC).

STUDY DESIGN

Expression of the MLH1, MSH2, MLH3, ATM, MRE11A, XRCC1, and PMS2 genes was evaluated by reverse transcription-quantitative polymerase chain reaction in the OSCC group (32 patients) and the control group (15 patients). The groups were compared by using the Mann-Whitney test, with Bonferroni correction. Associations between gene expression levels and clinical data were explored by using Pearson's and Spearman's correlation coefficients, with P value less than .05 indicating a significant difference.

RESULTS

The MLH1, MSH2, MLH3, ATM, MRE11A, XRCC1, and PMS2 genes were downregulated in the OSCC group compared with the control group, with significant values for MLH1 (P < .0001); MSH2 (P = .038); MLH3 (P < .0001); ATM (P < .0001); MRE11A (P < .0001); XRCC1 (P = .0004); and PMS2 (P = .008). Analysis of the correlation between gene expression and clinical data only revealed a significant negative correlation between age and expression of the PMS2 gene.

CONCLUSIONS

Expression of the DNA repair genes MLH1, MSH2, MLH3, ATM, MRE11 AMRE11A, XRCC1, and PMS2 was reduced in OSCC.

A case of adrenocortical carcinoma accompanying secondary acute adrenal hypofunction postoperation

Background

Adrenocortical carcinoma (ACC) is a rare, heterogeneous malignancy with a poor prognosis. ACCs are classified as functioning and non-functioning. The pathogenesis of ACC remains elusive, and diagnosis of ACC is currently based on pathology. In the absence of other effective approaches, surgical resection is the preferred treatment option.

Case presentation

Here, we report a case of ACC in the retroperitoneum. The patient underwent radical adrenalectomy and remained disease-free throughout a 6-month follow-up.

Conclusions

Radical surgical resection is an efficient therapy for ACC, and hydrocortisone can be used to alleviate symptoms of secondary acute adrenal hypofunction.

Proteome analysis of adrenal cortical tumors

INTRODUCTION

Adrenal tumor is a relatively common tumor. The discrimination between adrenal cortical adenoma (ACA) and adrenal cortical carcinoma (ACC) is crucial as these two diseases have distinct prognosis. ACA is a benign tumor curable by surgical excision, while the prognosis of ACC is extremely poor, with a 5-year mortality of 75-90%. Therefore, previous proteomic studies focused on markers allowing the differentiation between ACA and ACC.

AREAS COVERED

Several proteomic approaches based on the analysis of various samples such as human tissues, urine, and cell lines. In this review, we focused on proteomic studies performed to improve adrenal tumor diagnosis and identify ACC therapeutic targets. Expert commentary: The rapid development of cancer genomics provided a lot of information, which affects functional proteomics. In practice, differentially expressed proteins between ACA and ACC have been suggested in several proteomic studies and had a biologic implication in ACC.

Linking ATM Promoter Methylation to Cell Cycle Protein Expression in Brain Tumor Patients: Cellular Molecular Triangle Correlation in ATM Territory

Ataxia telangiectasia mutated (ATM) is a key gene in DNA double-strand break (DSB), and therefore, most of its disabling genetic alterations play an important initiative role in many types of cancer. However, the exact role of ATM gene and its epigenetic alterations, especially promoter methylation in different grades of brain tumors, remains elusive. The current study was conducted to query possible correlations among methylation statue of ATM gene, ATM/ retinoblastoma (RB) protein expression, D1853N ATM polymorphism, telomere length (TL), and clinicopathological characteristics of various types of brain tumors. Isolated DNA from 30 fresh tissues was extracted from different types of brain tumors and two brain tissues from deceased normal healthy individuals. DNAs were treated with bisulfate sodium using DNA modification kit (Qiagen). Methylation-specific polymerase chain reaction (MSP-PCR) was implicated to determine the methylation status of treated DNA templates confirmed by promoter sequencing. Besides, the ATM and RB protein levels were determined by immunofluorescence (IF) assay using monoclonal mouse antihuman against ATM, P53, and RB proteins. To achieve an interactive correlation, the methylation data were statistically analyzed by considering TL and D1853N ATM polymorphism. More than 73% of the brain tumors were methylated in ATM gene promoter. There was strong correlation between ATM promoter methylation and its protein expression (p < 0.001). As a triangle, meaningful correlation was also found between methylated ATM promoter and ATM protein expression with D1853N ATM polymorphism (p = 0.01). ATM protein expression was not in line with RB protein expression while it was found to be significantly correlated with ATM promoter methylation (p = 0.01). There was significant correlation between TL neither with ATM promoter methylation nor with ATM protein expression nor with D1853N polymorphism. However, TL has shown strong correlation with patient's age and tumor grade (p = 0.01). Given the important role of cell cycle checkpoint proteins as well as RB and ATM in TL and cancer evolution, further assessment is warranted to shed more light on the pathway linking the telomere instability to tumor progression. High ATM methylation rate in brain tumor patients could open a new avenue toward early screening and cancer therapy.

Molecular screening for a personalized treatment approach in advanced adrenocortical cancer

CONTEXT

Adrenocortical cancer (ACC) is a rare cancer with poor prognosis and scant treatment options. In ACC, no personalized approach has emerged but no extensive molecular screening has been performed to date.

OBJECTIVE

The objective of the study was to evaluate the presence of a large number of potentially targetable molecular events in a large cohort of advanced ACC.

DESIGN, SETTING, AND PARTICIPANTS

We used hot spot gene sequencing (Ion Torrent, 40 patients) and comparative genomic hybridization (CGH; 28 patients; a subset of the entire cohort) in adult stage III-IV ACC samples to screen for mutations and copy number abnormalities of potential interest for therapeutic use in 46 and 130 genes, respectively.

RESULTS

At least one copy number alteration or mutation was found in 19 patients (47.5%). The most frequent mutations were detected on TP53, ATM, and CTNNB1 [6 of 40 (15%), 5 of 40 (12.5%), and 4 of 40 (10%), respectively]. The most frequent copy number alterations identified were: amplification of the CDK4 oncogene (5 of 28; 17.9%) and deletion of the CDKN2A (4 of 28; 14.3%) and CDKN2B (3 of 28; 10.7%) tumor suppressor genes. Amplifications of FGFR1, FGF9, or FRS2 were discovered in three subjects (10.7%). Associated alterations were: deletions of CDKN2A, CDKN2B with ATM mutations, and TP53 mutations with CTNNB1 mutations.

CONCLUSIONS

No simple targetable molecular event emerged. Drugs targeting the cell cycle could be the most relevant new therapeutic approach for patients with advanced ACC. Inhibitors of the fibroblast growth factor receptor pathway could also be a therapeutic option in a subset of patients, whereas other targeted therapies should be considered on a case-by-case basis.

Management of adjuvant mitotane therapy following resection of adrenal cancer

Whenever adrenal cancer (ACC) is completely removed we should face the dilemma to treat by means of adjuvant therapy or not. In our opinion, adjuvant mitotane is the preferable approach in most cases because the majority of patients following radical removal of an ACC have an elevated risk of recurrence. A better understanding of factors that influence prognosis and response to treatment will help in stratifying patients according to their probability of benefiting from adjuvant mitotane, with the aim of sparing unnecessary toxicity to patients who are likely unresponsive. However, until significant advancements take place, we have to deal with uncertainty using our best clinical judgement and personal experience in the clinical decision process. In the present paper, we present the current evidence on adjuvant mitotane treatment and describe the management strategies of patients with ACC after complete surgical resection. We acknowledge the limit that most recommendations are based on personal experience rather than solid evidence.