Novel FH mutations in families with hereditary leiomyomatosis and renal cell cancer (HLRCC) and patients with isolated type 2 papillary renal cell carcinoma

Fumarase Deficiency: A Safe and Potentially Disease Modifying Effect of High Fat/Low Carbohydrate Diet

Fumarate hydratase deficiency (FHD) caused by biallelic alterations of the FH (fumarate hydratase) gene is a rare disorder of the tricarboxylic acid cycle, classically characterized by encephalopathy, profound psychomotor retardation, seizures, a spectrum of brain abnormalities and early death in childhood. Less common milder phenotypes with moderate cognitive impairment and long-term survival have been reported. In addition, heterozygous mutations of the FH gene are responsible for hereditary leiomyomatosis and renal cell cancer (HLRCC). There is currently no recommended disease modifying treatment for FHD and only isolated reports of unsuccessful dietary modifications. Herein, we describe the safe and possibly disease modifying effect of a high fat, low carbohydrate diet in a 14-year-old female with severe FHD.

The emerging role and targetability of the TCA cycle in cancer metabolism

The tricarboxylic acid (TCA) cycle is a central route for oxidative phosphorylation in cells, and fulfills their bioenergetic, biosynthetic, and redox balance requirements. Despite early dogma that cancer cells bypass the TCA cycle and primarily utilize aerobic glycolysis, emerging evidence demonstrates that certain cancer cells, especially those with deregulated oncogene and tumor suppressor expression, rely heavily on the TCA cycle for energy production and macromolecule synthesis. As the field progresses, the importance of aberrant TCA cycle function in tumorigenesis and the potentials of applying small molecule inhibitors to perturb the enhanced cycle function for cancer treatment start to evolve. In this review, we summarize current knowledge about the fuels feeding the cycle, effects of oncogenes and tumor suppressors on fuel and cycle usage, common genetic alterations and deregulation of cycle enzymes, and potential therapeutic opportunities for targeting the TCA cycle in cancer cells. With the application of advanced technology and in vivo model organism studies, it is our hope that studies of this previously overlooked biochemical hub will provide fresh insights into cancer metabolism and tumorigenesis, subsequently revealing vulnerabilities for therapeutic interventions in various cancer types.

Cascade Fumarate Hydratase mutation screening allows early detection of kidney tumour: a case report

BACKGROUND

Fumarate hydratase (FH) deficiency is a rare autosomal recessive disorder which results in a major defect in cellular metabolism. It presents in infancy with progressive encephalopathy, hypotonia, seizures and failure to thrive and is often fatal in childhood. It is caused by mutations in the FH gene (1q42.1) that result in deficiency of the citric acid cycle enzyme fumarate hydratase, resulting in accumulation of fumaric acid. Heterozygous germline mutations in the FH gene predispose to an aggressive autosomal dominant inherited early-onset kidney cancer syndrome: hereditary leiomyomatosis and renal cell cancer (HLRCC).

CASE PRESENTATION

Cascade FH mutation screening enabled the early diagnosis of a renal tumour in an asymptomatic parent of a child with fumarate hydratase deficiency, resulting in timely and possibly life-saving treatment.

CONCLUSION

While the theoretical risk of kidney cancer in parents of children with recessive fumarate hydratase deficiency is well recognized, to our knowledge this is the first report of a kidney tumour being detected in a parent by screening performed for this indication. This underscores the importance of offering lifelong kidney surveillance to such parents and other heterozygous relatives of children born with fumarate hydratase deficiency.

Immunohistochemical Characterization of Fumarate Hydratase (FH) and Succinate Dehydrogenase (SDH) in Cutaneous Leiomyomas for Detection of Familial Cancer Syndromes

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is caused by germline mutations in the FH gene, and is associated with increased incidence of leiomyomas and a potentially aggressive variant of renal cell carcinoma (HLRCC-associated RCC). Absent immunohistochemical expression of fumarate hydratase (FH) has previously been used to diagnose HLRCC-associated RCC, but immunohistochemical staining of leiomyomas is not standard practice. We performed immunohistochemistry (IHC) on whole sections from consecutive cutaneous leiomyomas from our archives to evaluate for both FH and succinate dehydrogenase B expression, in addition to clinicopathologic data collection and review of all hematoxylin and eosin-stained slides for blinded morphologic evaluation of features reported to be seen in HLRCC-associated uterine leiomyomas. Ninety-six cutaneous leiomyomas from 87 patients were identified; 12 of these specimens were from 7 patients with documented HLRCC. FH expression by IHC was absent in 9 specimens and retained in 85 specimens; 2 cases were equivocal with minimal FH expression. Seven of the 9 absent expression specimens were from patients with HLRCC, as were both of the equivocal specimens. The overall sensitivity and specificity of absent FH expression in leiomyomas for detection of patients with HLRCC were 70.0% and 97.6%, respectively. Inclusion of cases classified as equivocal increased sensitivity to 75.0%. Succinate dehydrogenase B expression was retained in 95 specimens and equivocal in 1 specimen. None of the evaluated morphologic features showed any association with leiomyomas in HLRCC. Loss of FH immunohistochemical expression in cutaneous leiomyomas is a sensitive and specific marker for detection of HLRCC, thus suggesting a role for prospective FH IHC in patients with these tumors to screen for HLRCC.

PheoSeq: A Targeted Next-Generation Sequencing Assay for Pheochromocytoma and Paraganglioma Diagnostics

Genetic diagnosis is recommended for all pheochromocytoma and paraganglioma (PPGL) cases, as driver mutations are identified in approximately 80% of the cases. As the list of related genes expands, genetic diagnosis becomes more time-consuming, and targeted next-generation sequencing (NGS) has emerged as a cost-effective tool. This study aimed to optimize targeted NGS in PPGL genetic diagnostics. A workflow based on two customized targeted NGS assays was validated to study the 18 main PPGL genes in germline and frozen tumor DNA, with one of them specifically directed toward formalin-fixed paraffin-embedded tissue. The series involved 453 unrelated PPGL patients, of whom 30 had known mutations and were used as controls. Partial screening using Sanger had been performed in 275 patients. NGS results were complemented with the study of gross deletions. NGS assay showed a sensitivity ≥99.4%, regardless of DNA source. We identified 45 variants of unknown significance and 89 pathogenic mutations, the latter being germline in 29 (7.2%) and somatic in 58 (31.7%) of the 183 tumors studied. In 37 patients previously studied by Sanger sequencing, the causal mutation could be identified. We demonstrated that both assays are an efficient and accurate alternative to conventional sequencing. Their application facilitates the study of minor PPGL genes, and enables genetic diagnoses in patients with incongruent or missing clinical data, who would otherwise be missed.

Mitochondrial Deficiencies in the Predisposition to Paraganglioma

Paragangliomas and pheochromocytomas are rare neuroendocrine tumours with a very strong genetic component. It is estimated that around 40% of all cases are caused by a germline mutation in one of the 13 predisposing genes identified so far. Half of these inherited cases are intriguingly caused by mutations in genes encoding tricarboxylic acid enzymes, namely SDHA, SDHB, SDHC, SDHD, and SDHAF2 genes, encoding succinate dehydrogenase and its assembly protein, FH encoding fumarate hydratase, and MDH2 encoding malate dehydrogenase. These mutations may also predispose to other type of cancers, such as renal cancer, leiomyomas, or gastro-intestinal stromal tumours. SDH, which is also the complex II of the oxidative respiratory chain, was the first mitochondrial enzyme to be identified having tumour suppressor functions, demonstrating that 80 years after his initial proposal, Otto Warburg may have actually been right when he hypothesized that low mitochondrial respiration was the origin of cancer. This review reports the current view on how such metabolic deficiencies may lead to cancer predisposition and shows that the recent data may lead to the development of innovative therapeutic strategies and establish precision medicine approaches for the management of patients affected by these rare diseases.

Comprehensive genomic and phenotypic characterization of germline FH deletion in hereditary leiomyomatosis and renal cell carcinoma

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a familial cancer syndrome associated with the development of cutaneous and uterine leiomyomas, and an aggressive form of type 2 papillary kidney cancer. HLRCC is characterized by germline mutation of the FH gene. This study evaluated the prevalence and clinical phenotype of FH deletions in HLRCC patients. Patients with phenotypic manifestations consistent with HLRCC who lacked detectable germline FH intragenic mutations were investigated for FH deletion. A series of 28 patients from 13 families were evaluated using a combination of a comparative genomic hybridization (CGH) array and/or CLIA-approved FH deletion/duplication analyses. Thirteen distinct germline deletions were identified in the 13 UOB families, including 11 complete FH gene deletions and 2 partial FH gene deletions. The size of eight evaluated complete FH deletions varied from ∼4.74 Mb to 249 kb, with all deletions resulting in additional gene losses. Two partial FH gene deletions were identified, with one resulting in loss of exon 1 and the upstream region of the FH gene only. Kidney cancer was diagnosed in 9 (32%) of 28 patients and 7 (54%) of 13 families possessing either complete or partial FH deletions. Cutaneous and uterine leiomyomas were observed at similar rates to those in FH point mutation families. Complete or partial FH gene alterations in HLRCC families are associated with all of the canonical HLRCC manifestations, including type 2 papillary kidney cancer and should be screened for in any patient at-risk for this disorder.

Hereditary leiomyomatosis and renal cell cancer syndrome: An update and review

Hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome is a rare genetic disorder that predisposes individuals to multiple cutaneous leiomyomas, renal cell carcinomas, and in women, uterine leiomyomas. Also known as Reed syndrome, it is caused by a germline heterozygous mutation of the fumarate hydratase tumor suppressor gene. HLRCC is associated with significant morbidity because of pain from cutaneous and uterine leiomyomas, the cutaneous pain often of unique character. Although genetic testing is currently considered the criterion standard to diagnose HLRCC, newer immunohistochemistry markers may provide rapid and cost effective alternatives to genetic testing. Because of the potentially aggressive nature of renal cell carcinomas that develop as early as in childhood, close annual cancer surveillance is desirable in individuals with HLRCC. In this review, we offer an update and an approach to the diagnosis, management, and renal cancer surveillance in HLRCC.

Tubulocystic Carcinoma of the Kidney With Poorly Differentiated Foci: A Frequent Morphologic Pattern of Fumarate Hydratase-deficient Renal Cell Carcinoma

An emerging group of high-grade renal cell carcinomas (RCCs), particularly carcinomas arising in the hereditary leiomyomatosis renal cell carcinoma syndrome (HLRCC), show fumarate hydratase (FH) gene mutation and loss of function. On the basis of similar cytomorphology and clinicopathologic features between these tumors and cases described as tubulocystic carcinomas with poorly differentiated foci (TC-PD) of infiltrative adenocarcinoma, we hypothesized a relationship between these entities. First, 29 RCCs with morphology of TC-PD were identified retrospectively and assessed for FH expression and aberrant succination (2SC) by immunohistochemistry (IHC), with targeted next-generation sequencing of 409 genes-including FH-performed on a subset. The 29 TC-PD RCCs included 21 males and 8 females, aged 16 to 86 years (median, 46), with tumors measuring 3 to 21 cm (median, 9) arising in the right (n=16) and left (n=13) kidneys. Family history or stigmata of HLRCC were identifiable only retrospectively in 3 (12%). These tumors were aggressive, with 79% showing perinephric extension, nodal involvement in 41%, and metastasis in 86%. Of these, 16 (55%) demonstrated loss of FH by IHC (14/14 with positive 2SC). In contrast, 5 (17%) showed a wild-type immunoprofile of FH+/2SC-. An intriguing group of 8 (28%) showed variable FH± positivity, but with strong/diffuse 2SC+. Next-generation sequencing revealed 8 cases with FH mutations, including 5 FH-/2SC+ and 3 FH±/2SC+ cases, but none in FH+/2SC- cases. Secondly, we retrospectively reviewed the morphology of 2 well-characterized cohorts of RCCs with FH-deficiency determined by IHC or sequencing (n=23 and n=9), unselected for TC-PD pattern, identifying the TC-PD morphology in 10 (31%). We conclude that RCCs with TC-PD morphology are enriched for FH deficiency, and we recommend additional workup, including referral to genetic counseling, for prospective cases. In addition, based on these and other observations, we propose the term "FH-deficient RCC" as a provisional term for tumors with a combination of suggestive morphology and immunophenotype but where genetic confirmation is unavailable upon diagnosis. This term will serve as a provisional nomenclature that will enable triage of individual cases for genetic counseling and testing, while designating these cases for prospective studies of their relationship to HLRCC.

Hereditary Renal Tumor Syndromes: Update on Diagnosis and Management

Hereditary renal cancers account for approximately 5%-8% of all renal tumors. Over the past 2 decades, a number of syndromes have been identified that predispose patients to early renal cancer development, representing all the major histologic types of tumor pathology. In this article, we describe the current knowledge concerning the cell type, known mechanism of tumor development, other manifestations of the syndrome, imaging findings, genetic screening, and imaging surveillance recommendations for each of the major syndromes associated with hereditary renal cancers.

Genetic predisposition to kidney cancer

Kidney cancer is not a single disease but is made up of a number of different types of cancer classified by histology that are disparate in presentation, clinical course, and genetic basis. Studies of families with inherited renal cell carcinoma (RCC) have provided the basis for our understanding of the causative genes and altered metabolic pathways in renal cancer with different histologies. Von Hippel-Lindau disease was the first renal cancer disorder with a defined genetic basis. Over the next two decades, the genes responsible for a number of other inherited renal cancer syndromes including hereditary papillary renal carcinoma, Birt-Hogg-Dube´syndrome, hereditary leiomyomatosis and renal cell carcinoma, and succinate dehydrogenase-associated renal cancer were identified. Recently, renal cell carcinoma has been confirmed as part of the clinical phenotype in individuals from families with BAP1-associated tumor predisposition syndrome and MiTF-associated cancer syndrome. Here we summarize the clinical characteristics of and causative genes for these and other inherited RCC syndromes, the pathways that are dysregulated when the inherited genes are mutated, and recommended clinical management of patients with these inherited renal cancer syndromes.

Adult Renal Cell Carcinoma: A Review of Established Entities from Morphology to Molecular Genetics

According to the current World Health Organization (WHO), renal cell carcinomas (RCCs) that primarily affect adults are classified into 8 major subtypes. Additional emerging entities in renal neoplasia have also been recently recognized and these are discussed in further detail by Mehra et al (Emerging Entities in Renal Neoplasia, Surgical Pathology Clinics, 2015, Volume 8, Issue 4). In most cases, the diagnosis of a RCC subtype can be based on morphologic criteria, but in some circumstances the use of ancillary studies can aid in the diagnosis. This review discusses the morphologic, genetic, and molecular findings in RCCs previously recognized by the WHO, and provides clues to distinction from each other and some of the newer subtypes of RCC. As prognosis and therapeutic options vary for the different subtypes of RCC, accurate pathologic distinction is critical for patient care.

Complete Penetrance and Absence of Intrafamilial Variability in a Large Family with Hereditary Leiomyomatosis and Renal Cell Carcinoma

BACKGROUND

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal dominant familial disorder due to FH mutation. Despite a considerable increase in information about the genetic background, inter- and intrafamilial phenotypic variability/penetrance are not well documented.

OBJECTIVE

To describe a large French HLRCC family and provide new data on penetrance and intrafamilial variability.

MATERIALS AND METHODS

The whole family was contacted for clinical examination, skin biopsy, uterine and kidney imagery and molecular analysis.

RESULTS

The family included 22 members in 3 generations. The second generation consisted of 13 members who were older than the expected age of onset of disease manifestations. Of the 12 available members of this second generation, 6 (1 man and 5 women, aged 44-57 years) had a novel FH mutation. All had the same mild phenotype with cutaneous asymptomatic leiomyomas, uterine fibroids (if women) and no kidney tumor. The other 6 members not bearing the familial mutation had normal clinical and radiological findings. In this second generation, the penetrance was therefore complete, and there was no intrafamilial variability in the clinical expression of the mutation.

CONCLUSION

This study provides additional data on genotype/phenotype correlation, intrafamilial variability and penetrance that should help to improve prognosis and genetic counseling.

A Case of Hereditary Leiomyomatosis and Renal Cell Carcinoma

A 49-year-old lady presented with multiple recurring painful lesions over her thighs, arms, and back. Past medical history included a left sided nephrectomy for renal cell carcinoma and a hysterectomy for multiple uterine fibroids (leiomyomas). Histopathological examination revealed changes consistent with pilar leiomyomas. Gene mutation analysis confirmed a diagnosis of hereditary leiomyomatosis and renal cell carcinoma. Hereditary leiomyomatosis and renal cell carcinoma is an uncommon autosomal dominant condition characterised by the concurrent presentation of cutaneous and uterine leiomyomas. Renal cell carcinoma associated with this condition is more aggressive and a significant cause of mortality. Due to this association with potentially fatal renal cell carcinoma we felt that it was important to highlight this case with an update on pathophysiology and management.

Molecular genetics and immunohistochemistry characterization of uncommon and recently described renal cell carcinomas

Renal cell carcinoma (RCC) compromises multiple types and has been emerging dramatically over the recent several decades. Advances and consensus have been achieved targeting common RCCs, such as clear cell carcinoma, papillary RCC and chromophobe RCC. Nevertheless, little is known on the characteristics of several newly-identified RCCs, including clear cell (tubulo) papillary RCC, Xp11 translocation RCC, t(6;11) RCC, succinate dehydrogenase (SDH)-deficient RCC, acquired cystic disease-associated RCC, hereditary leiomyomatosis RCC syndrome-associated RCC, ALK translocation RCC, thyroid-like follicular RCC, tubulocystic RCC and hybrid oncocytic/chromophobe tumors (HOCT). In current review, we will collect available literature of these newly-described RCCs, analyze their clinical pathologic characteristics, discuss their morphologic and immunohistologic features, and finally summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of RCCs, and eventually promote clinical management strategies.

Heritable Cancer Syndromes Related to the Hypoxia Pathway

Families of tumor-suppressor genes, such as those involved in homologous recombination or mismatch repair, contain individual genes implicated in hereditary cancer syndromes. Collectively, such groupings establish that inactivating germline changes in genes within pathways related to genomic repair can promote carcinogenesis. The hypoxia pathway, whose activation is associated with aggressive and resistant sporadic tumors, is another pathway in which tumor-suppressor genes have been identified. von Hippel–Lindau disease, some of the hereditary paraganglioma–pheochromocytoma (PGL/PCC) syndromes, and the syndrome of hereditary leiomyomatosis and renal cell carcinoma are heritable conditions associated with genes involved or associated with the hypoxia pathway. This review links these heritable cancer syndromes to the hypoxia pathway while also comparing the relative aggression and treatment resistance of syndrome-associated tumors to similar, sporadic tumors. The reader will become aware of shared phenotypes (e.g., PGL/PCC, renal cell carcinoma) among these three hypoxia-pathway-associated heritable cancer syndromes as well as the known associations of tumor aggressiveness and treatment resistance within these pathways.

Hereditary Renal Cell Carcinoma Syndromes: Clinical, Pathologic, and Genetic Features

Renal cell carcinomas associated with syndromes of a heritable nature account for about 4% of all renal cell carcinomas. They are characterized by an earlier age of onset, and are often multicentric and bilateral. Some of these patients may fit into well-characterized kidney cancer syndromes, while many more may have a genetic component that is not fully recognized or understood. The presence of extrarenal clinical features may suggest a specific renal tumor susceptibility syndrome. Moreover, each syndrome is associated with specific renal pathology findings. Recognition of individuals and families with a high risk of renal neoplasia is important so that surveillance for renal tumors may be initiated. This manuscript reviews the clinical, pathological, and molecular features of hereditary renal cell carcinoma syndromes with emphasis on the morphologic features of these tumors and the molecular mechanisms of hereditary renal tumorigenesis.

Morphology and Immunohistochemistry for 2SC and FH Aid in Detection of Fumarate Hydratase Gene Aberrations in Uterine Leiomyomas From Young Patients

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is an autosomal dominant syndrome that results from mutations in the fumarate hydratase (FH) gene. Patients with HLRCC are at risk for smooth muscle tumors of the uterus and skin as well as renal tumors. The renal cell carcinomas associated with HLRCC are usually high stage at presentation, aggressive, and have poor clinical outcomes. Therefore these patients and family members would benefit from early identification and appropriate surveillance. In small studies, HLRCC-associated uterine leiomyomas have been noted to display characteristic morphologic features including eosinophilic cytoplasmic inclusions, prominent eosinophilic nucleoli, and perinucleolar halos. Limited data suggest that positive staining for 2-succinocysteine (2SC) and loss of staining for FH by immunohistochemistry (IHC) can help with identification of HLRCC. The aim of this study was to evaluate the ability of morphology and IHC for FH and 2SC to help identify HLRCC in young patients with uterine smooth muscle tumors. We identified 194 evaluable uterine leiomyomas from women less than 40 years of age. We found FH gene aberrations by mutation analysis in 5 cases, a 2.6% incidence. Of these 5 cases, 4 displayed the characteristic morphologic features outlined above, whereas 1 did not. All 5 tumors with FH gene abnormalities showed positive staining for 2SC, whereas no FH gene aberrations were found in the 2SC-negative cases. Loss of FH staining was seen in 2 of the 5 cases, 1 with frameshift mutation and the other with homozygous deletion, whereas the remaining 3 cases with missense FH gene mutations were FH positive. Our study shows that morphologic features can be helpful for detection of HLRCC in uterine leiomyomas, although they may not be present in every case. IHC for 2SC and FH can be helpful: presence of positive staining for 2SC is sensitive and specific for detection of FH gene aberrations, whereas loss of staining for FH is specific but not sufficiently sensitive, as cases with missense mutations in the FH gene can show retained staining.

Diagnosis and Management of Hereditary Renal Cell Cancer

Renal cell cancer (RCC) is the common denominator for a heterogeneous group of diseases. The subclassification of these tumours is based on histological type and molecular pathogenesis. Insight into molecular pathogenesis has led to the development of targeted systemic therapies. Genetic susceptibility is the principal cause of RCC in about 2-4% of cases. Hereditary RCC is the umbrella term for about a dozen different conditions, the most frequent of which is von Hippel-Lindau disease . Here, we describe the main hereditary RCC syndromes, consider criteria for referral of RCC patients for clinical genetic assessment and discuss management options for patients with hereditary RCC and their at-risk relatives.

Genetic and Chromosomal Aberrations and Their Clinical Significance in Renal Neoplasms

The most common form of malignant renal neoplasms is renal cell carcinoma (RCC), which is classified into several different subtypes based on the histomorphological features. However, overlaps in these characteristics may present difficulties in the accurate diagnosis of these subtypes, which have different clinical outcomes. Genomic and molecular studies have revealed unique genetic aberrations in each subtype. Knowledge of these genetic changes in hereditary and sporadic renal neoplasms has given an insight into the various proteins and signalling pathways involved in tumour formation and progression. In this review, the genetic aberrations characteristic to each renal neoplasm subtype are evaluated along with the associated protein products and affected pathways. The potential applications of these genetic aberrations and proteins as diagnostic tools, prognostic markers, or therapeutic targets are also assessed.

Sustained NRF2 activation in hereditary leiomyomatosis and renal cell cancer (HLRCC) and in hereditary tyrosinemia type 1 (HT1)

The nuclear erythroid 2-like 2 transcription factor (NRF2), is a major regulator of cellular redox balance. Although NRF2 activation is generally regarded as beneficial to human health, recent studies have identified that sustained NRF2 activation is over-represented in many cancers. This raises the question regarding the role of NRF2 activation in the development and progression of those cancers. This review focuses on the mechanisms and the effects of NRF2 activation in two hereditary cancer predisposition syndromes: hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary tyrosinemia type 1 (HT1). Because the cancer initiating mutations in these hereditary syndromes are well defined, they offer a unique opportunity to explore the roles of NRF2 activation in the early stages of carcinogenesis. Over the years, a variety of approaches have been utilized to study the biology of HLRCC and HT1. In HLRCC, in vitro studies have demonstrated the importance of NRF2 activation in sustaining cancer cell proliferation. In the mouse model of HT1 however, NRF2 activation seems to protect cells from malignant transformation. In both HT1 and HLRCC, NRF2 activation promotes the clearance of electrophilic metabolites, enabling cells to survive cancer-initiating mutations. Biological insights gained from the hereditary syndromes' studies may shed light on to the roles of NRF2 activation in sporadic tumours.

Novel splice site mutation in the fumarate hydratase (FH) gene is associated with multiple cutaneous leiomyomas in a Japanese patient

Cutaneous leiomyoma is a benign skin tumor that originates from the smooth muscle, such as the arrector pili muscle of the hair follicles. Familial cases with multiple cutaneous leiomyomas exist, which typically show an autosomal dominant inheritance trait. Most patients with the disease are known to carry heterozygous germ line mutations in the fumarate hydratase (FH) gene and can be complicated by tumors in internal organs, especially uterine leiomyoma and renal cell cancer in high frequency. In this study, we identified a Japanese male patient with multiple cutaneous leiomyomas and found a novel heterozygous splice site mutation, c.738 + 2T>A, in the FH gene of the patient, which was unexpectedly inherited from his unaffected father. Further analysis demonstrated loss of heterozygosity in the tumor tissue, which resulted in a hemizygote state of the mutant allele. Expression studies with the tumor tissue showed that the mutation led to skipping of exon 5 at mRNA levels, which was predicted to cause an in-frame deletion of FH protein (p.Ser186_Gln246del). The protein structure analysis strongly suggested that the deletion would severely disrupt the conformation of the FH protein including the substrate-binding domain, and thus would severely affect the expression and the function. Our findings further disclose the molecular basis of multiple cutaneous leiomyomas and also provide precious information to the mutation carriers in the family for an early diagnosis of renal cell cancer in the future.

Papillary renal cell carcinoma: A review of the current therapeutic landscape

Renal cell carcinoma (RCC) is the most common cancer of the kidney and accounts for 2-3% of all adult malignancies. Clear cell carcinoma represents the most common histologic subtype, while papillary Renal Cell Carcinoma (pRCC) accounts for 10-20% of all renal cell cancers. While the inactivation of VHL gene can be found in the majority of clear cell carcinomas, different molecular mechanisms are involved into pRCC biology. Mutations in the MET oncogene are an essential step into the pathogenesis of hereditary pRCC forms, but they can be found only in a small rate of sporadic cases. Several agents, including anti-VEGF drugs and mTOR inhibitors, are possible options in the treatment of advanced and metastatic pRCC, following the demonstration of efficacy obtained in clinical trials including all RCC histologic subtypes. However, data specifically obtained in the subgroup of patients affected by pRCC are limited and not conclusive. Several ongoing trials are evaluating the efficacy of targeted therapy in papillary form. However, more rationale approaches based on molecular studies would help improving the outcome of these patients. Among others, MET inhibitors and targeted immunotherapy are promising new strategies for hereditary and sporadic disease. This review summarizes current knowledge on pRCC tumorigenesis and discusses recent and ongoing clinical trials with new therapeutic agents.

5-Hydroxymethylcytosine: An epigenetic mark frequently deregulated in cancer

The epigenetic mark 5-hydroxymethylcytosine (5hmC) has gained interest since 2009, when it was discovered that Ten-Eleven-Translocation (TET) proteins catalyze the conversion of 5-methylcytosine (5mC) into 5hmC. This conversion appears to be an intermediate step in the active DNA demethylation pathway. Factors that regulate DNA hydroxymethylation are frequently affected in cancer, leading to deregulated 5hmC levels. In this review, we will discuss the regulation of DNA hydroxymethylation, defects in this pathway in cancer, and novel therapies that may correct deregulated (hydroxy)methylation of DNA.

Hereditary leiomyomatosis and renal cell cancer (HLRCC): renal cancer risk, surveillance and treatment

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant condition in which susceptible individuals are at risk for the development of cutaneous leiomyomas, early onset multiple uterine leiomyomas and an aggressive form of type 2 papillary renal cell cancer. HLRCC is caused by germline mutations in the fumarate hydratase (FH) gene which inactivate the enzyme and alters the function of the tricarboxylic acid (Krebs) cycle. Issues surrounding surveillance and treatment for HLRCC-associated renal cell cancer were considered as part of a recent international symposium on HLRCC. The management protocol proposed in this article is based on a literature review and a consensus meeting. The lifetime renal cancer risk for FH mutation carriers is estimated to be 15 %. In view of the potential for early onset of RCC in HLRCC, periodic renal imaging and, when available, predictive testing for a FH mutation is recommended from 8 to 10 years of age. However, the small risk of renal cell cancer in the 10-20 years age range and the potential drawbacks of screening should be carefully discussed on an individual basis. Surveillance preferably consists of annual abdominal MRI. Treatment of renal tumours should be prompt and generally consist of wide-margin surgical excision and consideration of retroperitoneal lymph node dissection. The choice for systemic treatment in metastatic disease should, if possible, be part of a clinical trial. Screening procedures in HLRCC families should preferably be evaluated in large cohorts of families.

A practice guideline from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors: referral indications for cancer predisposition assessment

DISCLAIMER

The practice guidelines of the American College of Medical Genetics and Genomics (ACMG) and the National Society of Genetic Counselors (NSGC) are developed by members of the ACMG and NSGC to assist medical geneticists, genetic counselors, and other health-care providers in making decisions about appropriate management of genetic concerns, including access to and/or delivery of services. Each practice guideline focuses on a clinical or practice-based issue and is the result of a review and analysis of current professional literature believed to be reliable. As such, information and recommendations within the ACMG and NSGC joint practice guidelines reflect the current scientific and clinical knowledge at the time of publication, are current only as of their publication date, and are subject to change without notice as advances emerge. In addition, variations in practice, which take into account the needs of the individual patient and the resources and limitations unique to the institution or type of practice, may warrant approaches, treatments, and/or procedures that differ from the recommendations outlined in this guideline. Therefore, these recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. Genetic counseling practice guidelines are never intended to displace a health-care provider's best medical judgment based on the clinical circumstances of a particular patient or patient population. Practice guidelines are published by the ACMG or the NSGC for educational and informational purposes only, and neither the ACMG nor the NSGC "approve" or "endorse" any specific methods, practices, or sources of information.Cancer genetic consultation is an important aspect of the care of individuals at increased risk of a hereditary cancer syndrome. Yet several patient, clinician, and system-level barriers hinder identification of individuals appropriate for cancer genetics referral. Thus, the purpose of this practice guideline is to present a single set of comprehensive personal and family history criteria to facilitate identification and maximize appropriate referral of at-risk individuals for cancer genetic consultation. To develop this guideline, a literature search for hereditary cancer susceptibility syndromes was conducted using PubMed. In addition, GeneReviews and the National Comprehensive Cancer Network guidelines were reviewed when applicable. When conflicting guidelines were identified, the evidence was ranked as follows: position papers from national and professional organizations ranked highest, followed by consortium guidelines, and then peer-reviewed publications from single institutions. The criteria for cancer genetic consultation referral are provided in two formats: (i) tables that list the tumor type along with the criteria that, if met, would warrant a referral for a cancer genetic consultation and (ii) an alphabetical list of the syndromes, including a brief summary of each and the rationale for the referral criteria that were selected. Consider referral for a cancer genetic consultation if your patient or any of their first-degree relatives meet any of these referral criteria.

Uterine smooth muscle tumors with features suggesting fumarate hydratase aberration: detailed morphologic analysis and correlation with S-(2-succino)-cysteine immunohistochemistry

Rare, sporadic uterine leiomyomas arise in the setting of severe metabolic aberration due to a somatic fumarate hydratase mutation. Germline mutations account for the hereditary leiomyomatosis and renal cell carcinoma syndrome, which predisposes for cutaneous and uterine leiomyomas and aggressive renal cell carcinomas. Altered fumarate hydratase leads to fumarate accumulation in affected cells with formation of S-(2-succino)-cysteine, which can be detected with the polyclonal antibody. High levels of these modified cysteine residues are found characteristically in fumarate hydratase-deficient cells but not in normal tissues or tumors unassociated with hereditary leiomyomatosis and renal cell carcinoma syndrome. We hypothesized that S-(2-succino)-cysteine-positive leiomyomas, indicating fumarate hydratase aberration, have morphologic features that differ from those without S-(2-succino)-cysteine positivity. Hematoxylin and eosin-stained slides of uterine smooth-muscle tumors were prospectively analyzed for features suggesting hereditary leiomyomatosis and renal cell carcinoma syndrome, such as prominent eosinophilic macronucleoli with perinucleolar halos, yielding nine cases. Germline genetic testing for fumarate hydratase mutations was performed in three cases. A detailed morphological analysis was undertaken, and S-(2-succino)-cysteine immunohistochemical analysis was performed with controls from a tissue microarray (leiomyomas (19), leiomyosarcomas (29), and endometrial stromal tumors (15)). Of the nine study cases, four had multiple uterine smooth muscle tumors. All cases had increased cellularity, staghorn vasculature, and fibrillary cytoplasm with pink globules. All cases had inclusion-like nucleoli with perinuclear halos (7 diffuse, 1 focal). All showed diffuse granular cytoplasmic labeling with the S-(2-succino)-cysteine antibody. Two of three tested patients had germline fumarate hydratase mutations. Only one leiomyoma from the tissue microarray controls was immunohistochemically positive, and it showed features similar to other immunohistochemically positive cases. Smooth-muscle tumors with fumarate hydratase aberration demonstrate morphological reproducibility across cases and S-(2-succino)-cysteine immuno-positivity. Although the features described are not specific for the germline fumarate hydratase mutation or the hereditary leiomyomatosis and renal cell carcinoma syndrome, their presence should suggest fumarate hydratase aberration. Identifying these cases is an important step in the diagnostic workup of patients with possible hereditary leiomyomatosis and renal cell carcinoma.

Hereditary leiomyomatosis and renal cell carcinoma

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal-dominant hereditary syndrome, which is caused by germline mutations in the FH gene that encodes the tricarboxylic acid cycle enzyme fumarate hydratase (FH). HLRCC patients are predisposed to develop cutaneous leiomyomas, multiple, symptomatic uterine fibroids in young women resulting in early hysterectomies, and early onset renal tumors with a type 2 papillary morphology that can progress and metastasize, even when small. Since HLRCC-associated renal tumors can be more aggressive than renal tumors in other hereditary renal cancer syndromes, caution is warranted, and surgical intervention is recommended rather than active surveillance. At-risk members of an HLRCC family who test positive for the familial germline FH mutation should undergo surveillance by annual magnetic resonance imaging from the age of 8 years. Biochemical studies have shown that FH-deficient kidney cancer is characterized by a metabolic shift to aerobic glycolysis. It is hoped that through ongoing clinical trials evaluating targeted molecular therapies, an effective form of treatment for HLRCC-associated kidney cancer will be developed that will offer an improved prognosis for individuals affected with HLRCC-associated kidney cancer.

Hereditary leiomyomatosis and renal cell carcinoma syndrome-associated renal cancer: recognition of the syndrome by pathologic features and the utility of detecting aberrant succination by immunohistochemistry

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is an autosomal dominant disorder in which germline mutations of fumarate hydratase (FH) gene confer an increased risk of cutaneous and uterine leiomyomas and renal cancer. HLRCC-associated renal cancer is highly aggressive and frequently presents as a solitary mass. We reviewed the clinicopathologic features of 9 patients with renal tumors presenting as sporadic cases but who were later proven to have FH germline mutations. Histologically, all tumors showed mixed architectural patterns, with papillary as the dominant pattern in only 3 cases. Besides papillary, tubular, tubulopapillary, solid, and cystic elements, 6 of 9 tumors contained collecting duct carcinoma-like areas with infiltrating tubules, nests, or individual cells surrounded by desmoplastic stroma. Prominent tubulocystic carcinoma-like component and sarcomatoid differentiation were identified. Although all tumors exhibited the proposed hallmark of HLRCC (large eosinophilic nucleolus surrounded by a clear halo), this feature was often not uniformly present throughout the tumor. Prior studies have shown that a high level of fumarate accumulated in HLRCC tumor cells causes aberrant succination of cellular proteins by forming a stable chemical modification, S-(2-succino)-cysteine (2SC), which can be detected by immunohistochemistry. We thus explored the utility of detecting 2SC by immunohistochemistry in the differential diagnosis of HLRCC tumors and other high-grade renal tumors and investigated the correlation between 2SC staining and FH molecular alterations. All confirmed HLRCC tumors demonstrated diffuse and strong nuclear and cytoplasmic 2SC staining, whereas all clear cell (184/184, 100%), most high-grade unclassified (93/97, 96%), and the large majority of "type 2" papillary (35/45, 78%) renal cell carcinoma cases showed no 2SC immunoreactivity. A subset of papillary (22%) and rare unclassified (4%) tumors showed patchy or diffuse cytoplasmic staining without nuclear labeling, unlike the pattern seen with confirmed HLRCC tumors. Sequencing revealed no germline or somatic FH alterations in 14 tumors that either exhibited only cytoplasmic 2SC staining (n=5) or were negative for 2SC (n=9), despite their HLRCC-like morphologic features. Our results emphasize the pivotal role of pathologic examination in the diagnosis of HLRCC patients and indicate immunohistochemical detection of 2SC as a useful ancillary tool in the differentiation of HLRCC renal tumors from other high-grade renal cell carcinomas.

Dermoscopy as an adjuvant tool for detecting skin leiomyomas in patient with uterine fibroids and cerebral cavernomas

Background

Hereditary syndromes frequently need the cooperation of different specialties to increase diagnostic competence. Multiple cutaneous and uterine leiomyomatosis syndrome is a rare autosomal dominant disorder caused by the mutations of the fumarate hydratase gene, demonstrated in 80 to 100 percent of affected individuals. This can be linked to an increased risk of renal cancer in both sexes. The skin involvement is described to highlight the diagnostic role of the cutaneous counterpart in identifying this rare syndrome.

Case presentation

A 37-year-old woman suffering from several uterine fibroids presented multiple, painful, papulo-nodules on her left subscapular side, both forearms and legs. The patient underwent surgery on six lesions: five were leiomyomas, whilst one was a dermatofibroma. Genetic sequencing did not evidence known fumarate hydratase gene mutations. Dermoscopy showed a brown delicate pigmented network and included leiomyomas among the non-melanocytic benign skin tumours featuring a dermatofibroma-like pattern. Abdominal computerized-tomography scan did not reveal renal cancer, but brain magnetic resonance imaging showed one asymptomatic cerebral cavernoma. The patient benefited from the surgical removal of the five larger cutaneous lesions and from gabapentin, which relieved her pain.

Conclusions

This observation highlights the usefulness of dermoscopy in the diagnosis of cutaneous leiomyomas disclosing multiple cutaneous and uterine leiomyomatosis syndrome. Dermoscopy should be performed for non-melanocytic multiple lesions mimicking leiomyomas in a large number of patients, to establish a strict classification and identify false negative cases or evaluate them as dermatofibromas. In this case, the dermatologist recognized the risk of renal cancer and cerebral cavernomas.

Genetic variations in microRNAs and the risk and survival of renal cell cancer

MicroRNAs (miRNAs) are a class of short non-coding, single-stranded RNAs, which perform posttranscriptional regulatory functions as tumor suppressors or oncogenes. Single nucleotide polymorphisms (SNPs) in microRNAs (miRNAs) genes are currently being identified for contributing to cancer risk, prognosis and survival. We investigated whether genetic variations of miRNAs were associated with the risk and prognosis of renal cell carcinoma (RCC). We genotyped four common miRNA SNPs (i.e. miR-146a rs2910164, miR-149 rs2292832, miR-196a2 rs11614913 and miR-499 rs3746444) to assess their associations with RCC risk in a two-stage case-control study (355 cases and 362 controls in discovery set, meanwhile 647 cases and 660 controls in validation set), as well as RCC survival in 311 patients. We found that the miR-196a2 SNP rs11614913 was associated with RCC susceptibility in recessive model [CC versus TT/TC, adjusted odds ratio = 0.65, 95% confidence interval (CI) = 0.52-0.83] and with survival of RCC in dominant model (TC/CC versus TT, adjusted hazard ratio = 0.40, 95% CI = 0.18-0.89). Meanwhile, the rs11614913 CC genotype was associated with the significantly decreased expression of miR-196a-5p in 26 renal cancer tissues (P = 0.018). Moreover, luciferase reporter assays revealed the potential effect of rs11614913 SNP on the binding of miR-196a-3p to its targets. These results suggested that the miR-196a2 rs11614913 may contribute to the genetic susceptibility and prognosis for RCC, which may act as a biomarker for RCC occurrence and prognosis.

Hereditary kidney cancer syndromes

Inherited susceptibility to kidney cancer is a fascinating and complex topic. Our knowledge about types of genetic syndromes associated with an increased risk of disease is continually expanding. Currently, there are 10 syndromes associated with an increased risk of all types of kidney cancer, which are reviewed herein. Clear cell kidney cancer is associated with von Hippel Lindau disease, chromosome 3 translocations, PTEN hamartomatous syndrome, and mutations in the BAP1 gene as well as several of the genes encoding the proteins comprising the succinate dehydrogenase complex (SDHB/C/D). Type 1 papillary kidney cancers arise in conjunction with germline mutations in MET and type 2 as part of hereditary leiomyomatosis and kidney cell cancer (fumarate hydratase [FH] mutations). Chromophone and oncocytic kidney cancers are predominantly associated with Birt-Hogg-Dubé syndrome. Patients with Tuberous Sclerosis Complex (TSC) commonly have angiomyolipomas and rarely their malignant counterpart epithelioid angiomyolipomas. The targeted therapeutic options for the kidney cancer associated with these diseases are just starting to expand and are an area of active clinical research.

Molecular targets on the horizon for kidney and urothelial cancer

As whole-genome sequencing technology rapidly advances, the insights gained from deciphering cancer genomes are shifting the paradigm in the diagnosis and treatment of cancer with the promise of individualized treatment for each patient. Information gained in this way is extensive for certain cancers, but fairly limited in renal cell carcinomas and urothelial carcinoma. Mutations in multiple, potentially druggable genes have been identified in urothelial carcinomas; however, the association between molecular alterations and clinical outcome has not yet been robustly demonstrated. Data in this area are emerging in renal cell carcinoma, leading to the development of targeted agents that have improved overall survival. Unfortunately, these treatments rarely yield complete responses, are not curative, and development of resistance ensues. This Review will focus on the biology of non-hormonally driven urological cancers. We discuss how approaches using whole-genome sequencing can facilitate the discovery of biomarkers of drug sensitivity in both renal cell carcinomas and urothelial carcinomas. For renal cell carcinomas, we will describe how genomic and epigenomic mining has uncovered novel genes and pathways involved in tumorigenesis, tumour classification and mechanisms of resistance in the various subsets of this disease and the potential for exploiting these discoveries in the clinic.

MicroRNA profiles classify papillary renal cell carcinoma subtypes

Background:

Besides the conventional clear-cell renal cell carcinoma (ccRCC), papillary RCC (pRCC) is the second most common renal malignancy. Papillary RCCs can further be subdivided into two distinct subtypes. Although a clinical relevance of pRCC subtyping has been shown, little is known about the molecular characteristics of both pRCC subtypes.

Methods:

We performed microarray-based microRNA (miRNA) expression profiling of primary ccRCC and pRCC cases. A subset of miRNAs was identified and used to establish a classification model for ccRCC, pRCC types 1 and 2 and normal tissue. Furthermore, we performed gene set enrichment analysis with the predicted miRNA target genes.

Results:

Only five miRNAs (miR-145, -200c, -210, -502-3p and let-7c) were sufficient to identify the samples with high accuracy. In a collection of 111 tissue samples, 73.9% were classified correctly. An enrichment of miRNA target genes in the family of multidrug-resistance proteins was noted in all tumours. Several components of the Jak-STAT signalling pathway might be targets for miRNAs that define pRCC tumour subtypes.

Conclusion:

MicroRNAs are able to accurately classify RCC samples. Deregulated miRNAs might contribute to the high chemotherapy resistance of RCC. Furthermore, our results indicate that pRCC type 2 tumours could be dependent on oncogenic MYC signalling.

Is fibroid heterogeneity a significant issue for clinicians and researchers?

The clinical and scientific literature overwhelmingly deals with fibroids as a single entity or disease. This convenient assumption of homogeneity may be an important oversight given that substantial evidence exists for heterogeneity between fibroids at many levels. Failure to recognize and accommodate fibroid heterogeneity can have significant ramifications for both clinical treatment decisions and research protocol design. The aim of this article is to review the current knowledge of fibroid heterogeneity and to identify key areas where fibroid heterogeneity should be taken into consideration both clinically and when designing research protocols. Uterine leiomyomata display significant and well-documented heterogeneity in symptoms, diagnostic imaging appearance, pathology, genetic background and therapeutic requirements. Additional research is needed to better understand fibroid heterogeneity as it relates to pathogenesis, molecular targets for potential new therapies, patient symptoms and, ultimately, treatment. To this list should also be added heterogeneity of genetics, lifestyle and individual clinical characteristics of the fibroid. Increasingly, an understanding of uterine leiomyoma heterogeneity will be of importance for clinicians who see patients with this common and costly disease.

Genetic testing by cancer site: uterus

This review article discusses hereditary cancer predisposition syndromes with uterine manifestations. Lynch syndrome accounts for 2% to 3% of endometrial cancers. The identification of endometrial cancer patients at risk for Lynch syndrome is discussed, as are the characteristics of Lynch syndrome-associated endometrial cancer and the screening and prevention options for women at risk for Lynch syndrome-associated endometrial cancer. Endometrial cancer associated with PTEN hamartoma tumor syndrome (also known as Cowden syndrome) is also discussed. HLRCC (hereditary leiomyomatosis and renal cell carcinoma), which has an associated high risk of symptomatic uterine leiomyomas, is reviewed.

Hereditary papillary renal cell carcinoma primarily diagnosed in a cervical lymph node: a case report of a 30-year-old woman with multiple metastases

Background

Papillary renal cell carcinoma is a rare cancer. Some cases can be attributed to individuals with hereditary renal cell carcinomas usually consisting of the clear cell subtype. In addition, two syndromes with hereditary papillary renal cell carcinoma have been described. One is the hereditary leiomyomatosis and renal cell carcinoma, which is characterized by cutaneous and uterine leiomyomas and renal cell carcinoma mostly consisting of the papillary renal cell carcinoma type II with a worse prognosis.

Case presentation

We describe a case of a 30-year-old woman with hereditary leiomyomatosis and renal cell carcinoma syndrome with extensively metastasized papillary renal cell carcinoma, primarily diagnosed in a cervical lymph node lacking leiomyomas at any site.

Conclusion

Papillary renal cell carcinoma in young patients should be further investigated for a hereditary variant like the hereditary leiomyomatosis and renal cell carcinoma even if leiomyomas could not be detected. A detailed histological examination and search for mutations is essential for the survival of patients and relatives.

Promoter Methylation Analysis of IDH Genes in Human Gliomas

Mutations in isocitrate dehydrogenase (IDH)-1 or -2 are found in the majority of WHO grade II and III astrocytomas and oligodendrogliomas, and secondary glioblastomas. Almost all described mutations are heterozygous missense mutations affecting a conserved arginine residue in the substrate binding site of IDH1 (R132) or IDH2 (R172). But the exact mechanism of IDH mutations in neoplasia is not understood. It has been proposed that IDH mutations impart a “toxic gain-of-function” to the mutant protein, however a dominant-negative effect of mutant IDH has also been described, implying that IDH may function as a tumor suppressor gene. As most, if not all, tumor suppressor genes are inactivated by epigenetic silencing, in a wide variety of tumors, we asked if IDH1 or IDH2 carry the epigenetic signature of a tumor suppressor by assessing cytosine methylation at their promoters. Methylation was quantified in 68 human brain tumors, including both IDH-mutant and IDH wildtype, by bisulfite pyrosequencing. In all tumors examined, CpG methylation levels were less than 8%. Our data demonstrate that inactivation of IDH function through promoter hypermethylation is not common in human gliomas and other brain tumors. These findings do not support a tumor suppressor role for IDH genes in human gliomas.

Proteomics analysis of tumor microenvironment: Implications of metabolic and oxidative stresses in tumorigenesis

Tumorigenesis is always concomitant with microenvironmental alterations. The tumor microenvironment is a heterogeneous and complex milieu, which exerts a variety of stresses on tumor cells for proliferation, survival, or death. Recently, accumulated evidence revealed that metabolic and oxidative stresses both play significant roles in tumor development and progression that converge on a common autophagic pathway. Tumor cells display increased metabolic autonomy, and the hallmark is the exploitation of aerobic glycolysis (termed Warburg effect), which increased glucose consumption and decreased oxidative phosphorylation to support growth and proliferation. This characteristic renders cancer cells more aggressive; they devour tremendous amounts of nutrients from microenvironment to result in an ever-growing appetite for new tumor vessel formation and the release of more "waste," including key determinants of cell fate like lactate and reactive oxygen species (ROS). The intracellular ROS level of cancer cells can also be modulated by a variety of stimuli in the tumor microenvironment, such as pro-growth and pro-inflammatory factors. The intracellular redox state serves as a double-edged sword in tumor development and progression: ROS overproduction results in cytotoxic effects and might lead to apoptotic cell death, whereas certain level of ROS can act as a second-messenger for regulation of such cellular processes as cell survival, proliferation, and metastasis. The molecular mechanisms for cancer cell responses to metabolic and oxidative stresses are complex and are likely to involve multiple molecules or signaling pathways. In addition, the expression and modification of these proteins after metabolic or oxidative stress challenge are diverse in different cancer cells and endow them with different functions. Therefore, MS-based high-throughput platforms, such as proteomics, are indispensable in the global analysis of cancer cell responses to metabolic and oxidative stress. Herein, we highlight recent advances in the understanding of the metabolic and oxidative stresses associated with tumor progression with proteomics-based systems biology approaches.

Hereditary leiomyomatosis and renal cell cancer presenting as metastatic kidney cancer at 18 years of age: implications for surveillance

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant syndrome characterized by skin piloleiomyomas, uterine leiomyomas and papillary type 2 renal cancer caused by germline mutations in the fumarate hydratase (FH) gene. Previously, we proposed renal imaging for FH mutation carriers starting at the age of 20 years. However, recently an 18-year-old woman from a Dutch family with HLRCC presented with metastatic renal cancer. We describe the patient and family data, evaluate current evidence on renal cancer risk and surveillance in HLRCC and consider the advantages and disadvantages of starting surveillance for renal cancer in childhood. We also discuss the targeted therapies administered to our patient.

Familial renal cancer as an indicator of hereditary leiomyomatosis and renal cell cancer syndrome

Hereditary Leiomyomatosis and Renal Cell Carcinoma (HLRCC) is a hereditary condition which typically presents with cutaneous and uterine leiomyomata. Papillary type II renal cell carcinoma and other less common histologic subtypes of renal cancer have been reported in HLRCC. We describe the case of a 31-year-old man in which the pathology review of his renal carcinoma and a positive family history of renal carcinoma allowed for the identification of a pathogenic mutation in the FH gene (c.698G>A;p.R233H) confirming the diagnosis of HLRCC. Recognition of this syndrome allowed for appropriate surveillance as well as identification of at-risk family members. Pathology review is essential for accurate diagnosis of a hereditary cancer syndrome in the setting of familial renal cancer.

Fumarate hydratase gene mutation in two young patients with sporadic uterine fibroids

Fumarate hydratase (FH) is a key enzyme of the Krebs cycle. Germline mutations in the FH gene encoding fumarate hydratase cause autosomal dominant syndromes multiple cutaneous and uterine leiomyomata and hereditary leiomyomatosis and renal cell cancer (HLRCC). Few data have been published on the role of FH gene mutation in development of uterine fibroids outside the context of multiple cutaneous and uterine leiomyomata /HLRCC. We report two FH gene mutations, one novel and one previously described, in two young patients with sporadic uterine fibroids and decreased fumarate hydratase activity in lymphocytes. In patient 1, a novel heterozygous mutation c.892G>C was found. In patient 2 we detected heterozygous mutation c.584T>C. Both the patients had a negative family history for renal cancer and cutaneous leiomyomatosis. None of the relatives, however, underwent renal imaging at the time of writing. FH mutation carriers may be easily identified by analysis of fumarate hydratase activity in blood lymphocytes. We suggest performing fumarate hydratase activity or FH mutation screening in women with onset of uterine fibroids in their 20s and family history of uterine fibroids or other HLRCC-associated malignancies.

A novel fumarate hydratase-deficient HLRCC kidney cancer cell line, UOK268: a model of the Warburg effect in cancer

The role of energy deregulation and altered/adapted metabolism in tumor cells is an increasingly important issue in understanding cancer. Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an aggressive form of RCC characterized by germline mutation of fumarate hydratase (FH), followed by somatic loss of the remaining wild-type allele and known to be a highly metastatic and lethal malignancy compared to other RCCs. The intrinsic loss of normal tricarboxylic acid (TCA) cycle presumably aids tumorigenesis due to the necessary metabolic alterations required and the enforced dependence on glycolysis derived energy, mimicking the Warburg effect. Thus, there is considerable utility in establishing a preclinical cell model from these tumors to study energy metabolism deregulation, as well as developing new targeted therapeutic approaches for TCA cycle enzyme-deficient cancers. Here, we describe a new immortalized cell line, UOK268, derived from a patient's primary HLRCC-associated kidney cancer. This represents the first primary renal cell line to model TCA cycle gene loss and provides a perfect partner cell line to our previously described metastasis-derived HLRCC-associated cell line, UOK262. We identified a novel germline FH missense mutation, p.His192Asp, and the subsequent loss of heterozygosity in UOK268. The UOK268 cell line expressed mutant FH protein, which localized to the mitochondria, but with loss of almost all catalytic activity. The UOK268 cells had severely compromised oxidative phosphorylation and increased glycolytic flux. Ingenuity pathways analysis of human mitochondria-focused cDNA microarray (hMitChip3) gene chip data confirmed the altered mRNA expression patterns of genes involved in several important pathways, such as lipid metabolism, apoptosis, and energy production/glycolysis. UOK268 provides a unique model of a primary cell line demonstrating an enforced, irreversible Warburg effect and, combined with UOK262, provides a unique in vitro preclinical model for studying the bioenergetics of the Warburg effect in human cancer.