Osteogenic sarcoma and Rothmund Thomson syndrome

Activation of p38 MAP kinase and stress signalling in fibroblasts from the progeroid Rothmund-Thomson syndrome

Rothmund-Thomson fibroblasts had replicative lifespans and growth rates within the range for normal fibroblasts; however, they show elevated levels of the stress-associated p38 MAP kinase, suggestive of stress during growth. Treatment with the p38 MAP kinase inhibitor SB203580 increased both lifespan and growth rate, as did reduction of oxidative stress using low oxygen in some strains. At replicative senescence p53, p21(WAF1) and p16(INK4A) levels were elevated, and abrogation of p53 using shRNA knockdown allowed the cells to bypass senescence. Ectopic expression of human telomerase allowed Rothmund-Thomson fibroblasts to bypass senescence. However, activated p38 was still present, and continuous growth for some telomerised clones required either a reduction in oxidative stress or SB203580 treatment. Overall, the evidence suggests that replicative senescence in Rothmund-Thomson cells resembles normal senescence in that it is telomere driven and p53 dependent. However, the lack of RECQL4 leads to enhanced levels of stress during cell growth that may lead to moderate levels of stress-induced premature senescence. As replicative senescence is believed to underlie human ageing, a moderate level of stress-induced premature senescence and p38 activity may play a role in the relatively mild ageing phenotype seen in Rothmund-Thomson.

Multiple malignant diseases in a patient with Rothmund-Thomson syndrome with RECQL4 mutations: Case report and literature review

RECQL4 mutations cause genetic instability and increase the risk of malignant disease. We report on a patient with compound heterozygosity for two novel RECQL4 mutations: mutation c.1919_1924delTCACAG, p.L640_A642delinsP in exon 12 of the RECQL4 gene and mutation c.1704+1G>A in intron 10 of the RECQL4 gene. He subsequently developed large cell anaplastic T cell lymphoma at the age of 9 years, diffuse large cell B lymphoma and osteosarcoma when he was 14 years old, and finally acute lymphatic leukemia when he was 21 years old. The most remarkable clinical features are young age, spontaneous remission of diffuse large cell lymphoma, and severe CNS and skin toxicity of cytotoxic treatment.

Rothmund-Thomson syndrome

Rothmund-Thomson syndrome (RTS) is a genodermatosis presenting with a characteristic facial rash (poikiloderma) associated with short stature, sparse scalp hair, sparse or absent eyelashes and/or eyebrows, juvenile cataracts, skeletal abnormalities, radial ray defects, premature aging and a predisposition to cancer. The prevalence is unknown but around 300 cases have been reported in the literature so far. The diagnostic hallmark is facial erythema, which spreads to the extremities but spares the trunk, and which manifests itself within the first year and then develops into poikiloderma. Two clinical subforms of RTS have been defined: RTSI characterised by poikiloderma, ectodermal dysplasia and juvenile cataracts, and RTSII characterised by poikiloderma, congenital bone defects and an increased risk of osteosarcoma in childhood and skin cancer later in life. The skeletal abnormalities may be overt (frontal bossing, saddle nose and congenital radial ray defects), and/or subtle (visible only by radiographic analysis). Gastrointestinal, respiratory and haematological signs have been reported in a few patients. RTS is transmitted in an autosomal recessive manner and is genetically heterogeneous: RTSII is caused by homozygous or compound heterozygous mutations in the RECQL4 helicase gene (detected in 60-65% of RTS patients), whereas the aetiology in RTSI remains unknown. Diagnosis is based on clinical findings (primarily on the age of onset, spreading and appearance of the poikiloderma) and molecular analysis for RECQL4 mutations. Missense mutations are rare, while frameshift, nonsense mutations and splice-site mutations prevail. A fully informative test requires transcript analysis not to overlook intronic deletions causing missplicing. The diagnosis of RTS should be considered in all patients with osteosarcoma, particularly if associated with skin changes. The differential diagnosis should include other causes of childhood poikiloderma (including dyskeratosis congenita, Kindler syndrome and Poikiloderma with Neutropaenia), other rare genodermatoses with prominent telangiectasias (including Bloom syndrome, Werner syndrome and Ataxia-telangiectasia) and the allelic disorders, RAPADILINO syndrome and Baller-Gerold syndrome, which also share some clinical features. A few mutations recur in all three RECQL4 diseases. Genetic counselling should be provided for RTS patients and their families, together with a recommendation for cancer surveillance for all patients with RTSII. Patients should be managed by a multidisciplinary team and offered long term follow-up. Treatment includes the use of pulsed dye laser photocoagulation to improve the telangiectatic component of the rash, surgical removal of the cataracts and standard treatment for individuals who develop cancer. Although some clinical signs suggest precocious aging, life expectancy is not impaired in RTS patients if they do not develop cancer. Outcomes in patients with osteosarcoma are similar in RTS and non-RTS patients, with a five-year survival rate of 60-70%. The sensitivity of RTS cells to genotoxic agents exploiting cells with a known RECQL4 status is being elucidated and is aimed at optimizing the chemotherapeutic regimen for osteosarcoma.

Rothmund-Thomson syndrome helicase, RECQ4: on the crossroad between DNA replication and repair

RECQ proteins are conserved DNA helicases in both prokaryotes and eukaryotes. The importance of the RECQ family helicases in human health is demonstrated by their roles as cancer suppressors that are vital for preserving genome integrity. Mutations in one of the RECQ family proteins, RECQ4, not only result in developmental abnormalities and cancer predispositions, but are also linked to premature aging. Therefore, defining the function and regulation of the RECQ4 protein is fundamental to our understanding of both the aging process and cancer pathogenesis. This review will summarize the clinical effect of RECQ4 in human health, and discuss the recent progress and debate in defining the complex molecular function of RECQ4 in DNA metabolism.

Multiple cutaneous neoplasms in a patient with Rothmund-Thomson syndrome: case report and published work review

Rothmund-Thomson syndrome (RTS) is a rare genodermatosis characterized by early poikilodermatous skin lesions, often combined with juvenile cataracts, photosensitivity and bone defects. Data in the published work indicate that there is an increased risk of RTS patients developing malignant tumors. Herein, we report the multiple skin carcinomas observed in a case of RTS and review the published work on the occurrence of malignant tumors in these patients. We report the case of a 63-year-old male with RTS who developed multiple cutaneous neoplasms (three basal cell carcinomas, three squamous cell carcinomas and Bowen's disease) over the previous 15 years. A published work review confirmed that RTS is a genetic condition that predisposes subjects to the development of bone tumors, especially at an early age, and skin tumors at an adult age. Therefore, alongside careful osteoarticular monitoring to identify a bone tumor quickly, during the life of a patient suffering from the syndrome, it is just as important to take appropriate preventive action and monitor the possible onset of skin tumors.

Biochemical characterization of the RECQ4 protein, mutated in Rothmund-Thomson syndrome

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disorder characterized by growth deficiency, skin and skeletal abnormalities, and a predisposition to cancer. Mutations in the RECQ4 gene, one of five human homologs of the E. coli recQ gene, have been identified in a subset of RTS patients. Cells derived from RTS patients show high levels of chromosomal instability, implicating this protein in the maintenance of genomic integrity. However, RECQ4 is the least characterized of the RecQ helicase family with regard to its molecular and catalytic properties. We have expressed the human RECQ4 protein in E. coli and purified it to near homogeneity. We show that RECQ4 has an ATPase function that is activated by DNA, with ssDNA being much more effective than dsDNA in this regard. We have determined that a DNA length of 60 nucleotides is required to maximally activate ATP hydrolysis by RECQ4, while the minimal site size for ssDNA binding by RECQ4 is between 20 and 40 nucleotides. Interestingly, RECQ4 possesses a single-strand DNA annealing activity that is inhibited by the single-strand DNA binding protein RPA. Unlike the previously characterized members of the RecQ family, RECQ4 lacks a detectable DNA helicase activity.

RecQ helicases: suppressors of tumorigenesis and premature aging

The RecQ helicases represent a subfamily of DNA helicases that are highly conserved in evolution. Loss of RecQ helicase function leads to a breakdown in the maintenance of genome integrity, in particular hyper-recombination. Germ-line defects in three of the five known human RecQ helicases give rise to defined genetic disorders associated with cancer predisposition and/or premature aging. These are Bloom's syndrome, Werner's syndrome and Rothmund-Thomson syndrome, which are caused by defects in the genes BLM, WRN and RECQ4 respectively. Here we review the properties of RecQ helicases in organisms from bacteria to humans, with an emphasis on the biochemical functions of these enzymes and the range of protein partners that they operate with. We will discuss models in which RecQ helicases are required to protect against replication fork demise, either through prevention of fork breakdown or restoration of productive DNA synthesis.

Two primary osteosarcomas in a patient with Rothmund-Thomson syndrome

Rothmund-Thomson syndrome is an autosomal recessive disorder characterized by poikilodermatous skin changes that develop in infancy. Associated manifestations include juvenile cataracts, sparse hair, short stature, skeletal defects, dystrophic nails and teeth, and hypogonadism. An increased incidence of malignancy, including osteosarcoma, has been reported in patients with Rothmund-Thomson syndrome. The molecular basis of the disorder is not known. This report describes a patient with Rothmund-Thomson syndrome in whom two primary osteosarcomas developed 12 years apart. The presentation, diagnosis, and treatment of osteosarcoma in this patient with Rothmund-Thomson syndrome are described. Cytogenetic and molecular analysis of peripheral blood and skin fibroblasts had low level mosaicism for trisomy of chromosomes 2 and 8. Although several patients have been described with mosaic trisomy 8 and i(2q) (mosaic isochromosome for the long arm of chromosome 2), the patient described here is the first to have mosaic trisomy for the entire chromosomes 2 and 8. The cytogenetic findings in this patient are consistent with an underlying defect in chromosomal stability.

Rothmund-Thomson syndrome due to RECQ4 helicase mutations: report and clinical and molecular comparisons with Bloom syndrome and Werner syndrome

Rothmund-Thomson syndrome (RTS), an autosomal recessive disorder, comprises poikiloderma, growth deficiency, some aspects of premature aging, and a predisposition to malignancy, especially osteogenic sarcomas. Two kindreds with RTS were recently shown to segregate for mutations in the human RECQL4 helicase gene. We report identification of a new RTS kindred in which both brothers developed osteosarcomas. Mutation analysis of the RECQL4 gene was performed on both brothers and both parents. The brothers were shown to be compound heterozygotes for mutations in the RECQL4 gene, including a single basepair deletion in exon 9 resulting in a frameshift and early termination codon and a base substitution in the 3-prime splice site in the intron-exon boundary of exon 8, which would be predicted to cause a deletion of at least part of a consensus helicase domain. Each parent was shown to be a heterozygote carrier for one mutation. This report strengthens the association between mutations in RECQL4 helicase gene and RTS. Two other recessive disorders, Bloom syndrome and Werner syndrome, are known to be due to other human RECQ helicase gene mutations. These three disorders all manifest abnormal growth, premature aging, and predisposition to site-specific malignancies. The clinical and molecular aspects of RTS, Bloom syndrome, and Werner syndrome are compared and contrasted.

Osteosarcoma associated with absent thumbs: a report of two cases

An 8-year-old Hispanic boy with a hypoplastic left thumb, absent right thumb, and short stature experienced right leg pain and limp. A right tibial lesion was imaged and found to be osteosarcoma on biopsy. A 6-year-old Hispanic girl with congenitally absent thumbs experienced a pathologic fracture of her left femur after a minor sports injury. The radiologic abnormality seen was diagnosed as osteosarcoma on biopsy. Both patients continue to do well after intensive preoperative and postoperative high-dose chemotherapy and definitive reconstructive limb surgery. Osteosarcoma has been linked to several congenital syndromes in which absent thumbs are a feature. These two patients with absent thumbs and no definable syndrome experiencing osteosarcoma suggest that congenitally absent thumbs might be a risk factor for osteosarcoma in the absence of a syndrome.

Aplastic anemia in a patient with Rothmund-Thomson syndrome

This report is the first to describe constitutional aplastic anemia in a patient with Rothmund-Thomson syndrome (also called poikiloderma congenitale), a disease characterized by multiple cutaneous and extracutaneous findings. The findings suggest that although Rothmund-Thomson syndrome is a rare disease, vigilance for the development of associated hematologic abnormalities is warranted.

Multicentric osteosarcoma, Rothmund-Thomson syndrome, and secondary nasopharyngeal non-Hodgkin's lymphoma: a case report and review of the literature

PURPOSE

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disease characterized by poikiloderma, photosensitivity, skeletal deformities, and other changes. It is also associated with an increased risk of malignancies, including osteosarcoma. Sixteen previous cases of RTS and osteosarcoma have been reported.

PATIENT

A patient with RTS in whom multicentric osteosarcoma developed is described. After surgery and chemotherapy, a secondary malignant neoplasm (SMN) developed consistent with nasopharyngeal non-Hodgkin's lymphoma.

RESULTS

The patient was treated with anti-CD20 monoclonal antibody and is in complete remission.

CONCLUSION

This is the first report of a patient with RTS treated for osteosarcoma in whom a SMN developed. Potential factors involved in this SMN include genetic predisposition and previous chemotherapy.

Primary patellar tumors

Eight cases of primary tumors of the patella were identified in a consecutive series of 587 patients treated surgically for benign or malignant bone tumors. Six cases were benign (5 giant cell tumors and 1 chondroblastoma), and there were 2 malignant tumors (osteosarcoma and malignant fibrous histiocytoma). Both patients with malignant lesions had Rothmund-Thomson syndrome. Benign pulmonary metastases developed in 2 of the patients with giant cell tumor and 1 patient now is deceased 72 months after surgery. Two patients were treated before referral to a tertiary care center; 1 with patellectomy before histologic diagnosis and 1 with curettage. Both resulted in extension of disease into the knee joint. Tumors of the patella require careful assessment before surgical management. Conservation of the bone can be achieved in benign lesions that have adequate residual bone remaining at the articular surface. Conservation of the extremity is possible in malignant tumors, but reconstruction of the extensor mechanism is difficult.

Osteosarcomatosis with Rothmund-Thomson syndrome

We describe the second reported case of multicentric osteosarcoma associated with Rothmund-Thomson syndrome (RTS), a rare hereditary cancer-prone genodermatosis characterized by typical cutaneous lesions and other non-dermatological pathological manifestations, particularly skeletal changes. A high incidence of malignant disorders has been found in RTS patients. This could be explained by the diminished capacity of DNA-repair demonstrated in the fibroblasts of RTS patients following exposure to oncogenic stimuli. The severe cutaneous lesions and the benign bone lesions found in RTS may be considered a predisposing factor to the particularly frequent skin carcinoma and osteogenic sarcoma encountered in these cancer-prone patients. A brief review of the literature is given, with a discussion of the association between these two rare conditions.

Rothmund-Thomson syndrome and osteosarcoma

The Rothmund-Thomson syndrome (RTS), also called poikiloderma congenitale is a rare autosomal recessive disease first described in 1868. This syndrome includes most frequently seen skin lesions (atrophy, telangiectases, pigmentation), cataracts and bone defects (dysostosis, dysplasia). Some authors describe an association with malignancy. We report three cases of Rothmund-Thomson syndrome associated with osteosarcoma. After cutaneous epithelioma, osteosarcoma is the most frequent malignancy. Thus, patients with RTS need a careful survey. The treatment did not differ from sporadic osteosarcoma. Chemosensitivity and toxicity are also not different.

Osteogenic sarcoma in the Rothmund-Thomson syndrome

Two children who had the Rothmund-Thomson syndrome and developed osteosarcoma are reported. The 10 previously reported cases are reviewed. The osteosarcomas developed at a younger age than normally expected and 66% occurred in the tibia/fibula. Four of the five patients for whom information was available showed undue sensitivity to cancer chemotherapy agents with prolonged myelosuppression and severe mucositis. It is recommended that doxorubicin in particular should be given with extreme caution in such patients.

Rothmund-Thomson syndrome in siblings: evidence for acquired in vivo mosaicism

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disorder characterized by skin abnormalities that appear in infancy, skeletal abnormalities, juvenile cataracts and other manifestations of premature aging, and a predisposition to malignancy. The diagnosis is made on clinical grounds as no consistent laboratory test has been identified. Chromosome studies have been reported for only three patients with RTS and in two of these three, trisomy 8 mosaicism was found. We performed a variety of cytogenetic and molecular genetic studies on two siblings with RTS and on their phenotypically normal parents. Two chromosomally abnormal clones involving either trisomy 8 or i(8q) were found in both patients with RTS. These clones were present in vivo, as they were seen in interphase buccal smears and lymphocytes from unstimulated preparations using both conventional cytogenetic studies and fluorescence in situ hybridization (FISH) with a centromere probe for chromosome 8. These results suggest that RTS is associated with in vivo clonal chromosomal rearrangements causing an acquired somatic mosaicism.

[Rothmund-Thomson syndrome and osteosarcoma]

BACKGROUND

The Rothmund-Thomson syndrome is a hereditary dermatosis frequently accompanied by less well-known non dermatologic features including osteogenic sarcoma.

CASE REPORT

A girl developed the classical dermatologic features of the Rothmund-Thomson syndrome since the first months of life. When she was 6 years old, she suffered from painful limitation of motion of her left leg. X-rays, MNR imaging and bone scintigraphy showed typical features of osteosarcoma of the distal portion of the femur. Diagnosis was confirmed by histologic examination through open biopsy. The search for metastatic lesions was negative. The patient was given chemotherapy and the tumor was resected 45 days later followed by postoperative chemotherapy.

CONCLUSION

About 12 similar cases of osteosarcoma have been reported in patients with the Rothmund-Thomson syndrome. A review of literature allows to recognize some peculiar features of such association.

Rothmund-Thomson syndrome and Addison disease

We report an 18-year-old man with the unusual combination of Rothmund-Thomson syndrome (RTS) and Addison disease. He was admitted when he was 26 months old because of short stature, dehydration, metabolic acidosis, hyperpigmentation, and typical skin lesions. Because his growth remained delayed, at age 10 years he was given a trial of recombinant growth hormone. After six years of treatment no improvement in height, bone, or sexual maturation was observed. This fact may be related to a defect in connective tissue metabolism. Chromosomal analysis of peripheral blood lymphocytes revealed increased numbers of breaks and gaps. Fibroblasts cultured from affected skin did not grow. Patients with RTS are prone to developing cancer, but no malignant disease was found in our patient. Early diagnosis and treatment of both endocrinologic and malignant complications are essential for survival of patients with this rare syndrome.