Rodney E. Shackelford

ATM protects against oxidative stress induced by oxidized low-density lipoprotein

Highlights ► OxLDL promotes induction of pATM and p21 in fibroblasts/endothelial cells. ► OxLDL activates ATM-kinase by a doubled-stranded DNA break-independent mechanism. ► ATM-deficient fibroblasts exhibit low cell viability but increased oxidative stress towards oxLDL. ► ATM expression exerts protective effects against ox-LDL-induced cellular toxicity.

Liquid bead array technology in the detection of common translocations in acute and chronic leukemias.

Hematologic malignancies often have specific chromosomal translocations that promote cancer initiation and progression. Translocation identification is often vital in the diagnosis, prognosis, and treatment of malignancies. A variety of methods including metaphase cytogenetics, in situ hybridization, microarray techniques, Southern blotting, and many variations of PCR are used to identify translocations. While all these techniques have utility, many have drawbacks limiting their clinical usefulness: high cost, slow turnaround time, low density, large sample requirements, high complexity, and difficult validation and standardization. Multiplexed RT-PCR combined with liquid bead array detection overcomes many of these limitations, allowing simultaneous amplification and detection of multiple translocations within one patient sample. This system has high reliability, reproducibility, and flexibility; low cost and low complexity; rapid turnaround time; and appropriate analyte density. Recently, Asuragen Inc. has developed a multiplexed RT-PCR liquid bead array panel that simultaneously analyzes 12 fusion transcripts found in four major types of hematologic malignancies, allowing rapid and efficient diagnosis. In this chapter, we review liquid bead array technology in relation to the specific hematologic translocations analyzed in the Signature LTx panel.

Molecular Pathology and Diagnostics of Thyroid and Parathyroid Malignancies

Malignancies of the thyroid and parathyroid glands are rare oncologic entities that range in clinical behavior from relatively indolent to extremely aggressive malignancies. Presently, establishing a diagnosis and prognosis for thyroid and parathyroid malignancies largely depends on histology supplemented with immunohistochemical analysis. Over the past 20 years, different histologic subtypes of thyroid cancer have been shown to carry specific genetic alterations, which are often preferentially associated with, or unique to, each subtype. In many cases, these genetic alterations have been analyzed via molecular-genetic testing techniques to help establish a diagnosis in cases where histology and immunohistochemistry alone cannot. In addition, such testing has occasionally been used to determine prognosis. Presently, clinical molecular diagnostic testing is not performed on parathyroid tumors. However, differences between parathyroid hyperplasia, adenomas, and carcinomas have been detected via molecular testing. With additional research, these differences may become more fully understood and applied to molecular diagnostics. Thus, although presently not extensively employed, molecular diagnostics of the thyroid and parathyroid are likely to become increasingly important in determining the diagnosis and prognosis of these malignancies, especially for histologically difficult cases. Furthermore, pharmacologic inhibitors of many of the oncogenes mutated in these malignancies are being developed. With time, molecular diagnostic testing for these mutations is likely to be implemented to aid in choosing optimal chemotherapeutic treatment regimens.

Molecular Pathology and Diagnostics of Prostate Cancer

Prostate cancer (PCa) is the most common malignancy among men and is the second leading cause of cancer-related deaths in the United States and Europe. The molecular alterations underlying PCa have recently been shown to be quite complex, involving many different genes, microRNA species, epigenetic and mitochondrial changes, and multiple gene translocations. Because of the highly complex molecular changes underlying this malignancy, PCa molecular diagnostics are exceptionally complex and have only recently led to useful molecular tests. Here, we will review several promising areas in the molecular diagnostics of PCa and try to indicate which ones may have clinical utility in the near future.

Molecular-Genetic Testing in Penile, Scrotal, and Testicular Cancer

Malignant tumors of the penis, scrotum, and testes are rare, accounting for roughly 0.5 % of all male tumors. Presently the diagnosis of these tumors depends mainly on histologic examination, supplemented with immunohistochemistry. Over the past 20 years, however, many genetic changes have been identified that are largely specific to different tumors and tumor classes, such as 12p gains in testicular germ cell tumors. Although not commonly employed in the analysis of these tumors, molecular genetic testing is now available for many of these tumors and is becoming an increasingly important adjunct in their diagnosis and treatment. Here, we summarize what is known about the molecular pathology of these tumors and some of the molecular testing modalities currently available. We also briefly discuss the possible future molecular diagnostics of these tumors.

Molecular-Genetic Testing in Hepatocellular Carcinoma and Its Premalignant Conditions

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide and the third most common cause of malignancy-associated death. Presently there are relatively few molecular genetic testing directly performed on HCC. However, many molecular genetic tests are performed on conditions that increase the risk for HCC or modify drug treatments for conditions that increase HCC risk, including hepatitis B and C, hemochromatosis, and interleukin-28b testing. Here we review the common molecular diagnostic genetic tests associated with HCC diagnosis and treatment.

Molecular Pathology and Diagnostics of Gynecologic Malignancies

Gynecologic malignancies account for roughly 13 % of solid tissue tumors in women. Many of these malignancies, such as many ovarian tumors, first present at an advanced stage, making them difficult to treat. Until recently the analysis of these malignancies was largely limited to hematoxylin-eosin-stained slide examination, supplemented with immunohistochemical stains. Recently, molecular diagnostic techniques have been applied to these tumors with some success, especially with BRCA1/2 mutations and Lynch syndrome analyses. Here, we describe the present molecular diagnostic tests applied to gynecologic malignancies and discuss possible future developments in this field.

Molecular Pathology and Diagnostics in Esophago-gastric Cancer

Esophageal and gastric cancers are the eighth and fourth most common cancers worldwide, respectively. Because of their often-aggressive clinical courses and high fatality rates, they represent the sixth and second most common causes of cancer deaths worldwide. The diagnosis of these malignancies is mainly established by their clinical presentation, combined with biopsy and subsequent histologic analysis of hematoxylin-eosin-stained tissue sections. Recently, however, molecular studies have become increasingly important in establishing a diagnosis and prognosis and guiding the clinical management of these malignancies. For some subtypes of these malignancies, such as hereditary diffuse gastric cancer, molecular diagnostics is central in establishing a diagnosis and in determining appropriate clinical management. Here, we review current methods and recommendations for molecular-genetic testing for esophageal and gastric cancers and briefly discuss future possible applications of this technology to these malignancies.

Molecular Pathology and Diagnostics of Colorectal Cancer

Colorectal carcinoma (CRC) is the third most common malignancy in the United States and is the second leading cause of cancer deaths. Over the past 20 years, our knowledge of this CRC carcinogenesis has enormously increased; presently, several molecular diagnostic tests are commonly employed to analyze stage IV CRC and familiar CRC syndromes to determine treatment options and CRC inheritance and risk. More recently the number of CRC diagnostic tests has enormously expanded as our knowledge of CRC carcinogenesis has increased. Here, we review the standard tests employed in CRC, such as KRAS and Braf analyses, and also include less commonly employed tests related to familiar CRC and microsatellite instability. Last, we focus on possible future CRC genetic tests and testing modalities, focusing on techniques such as microarray and mass spectrophotometry.