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1.
Cardiovasc Intervent Radiol ; 47(4): 407-415, 2024 Apr.
Article En | MEDLINE | ID: mdl-38509339

Retinoblastoma is the most common eye malignancy in children that if left untreated can invade intraocular structures, metastasize, and rarely lead to death. Traditionally treated with systemic chemotherapy, Intra-arterial chemotherapy is gaining popularity as it allows for the direct administration of chemotherapy through the ophthalmic artery, thus reducing systemic side effects. Intra-arterial chemotherapy procedures have evolved, with refinements to reduce risks and radiation exposure. Intra-arterial chemotherapy boasts an impressive technical success rate and one year ocular survival even amongst advanced cases. This review offers a thorough examination of the technique, indications, contraindications, outcomes, and alternative options for Intra-arterial chemotherapy.


Radiation Exposure , Retinal Neoplasms , Retinoblastoma , Child , Humans , Infant , Retinoblastoma/chemically induced , Retinoblastoma/drug therapy , Retinal Neoplasms/chemically induced , Retinal Neoplasms/drug therapy , Infusions, Intra-Arterial , Ophthalmic Artery/pathology , Melphalan/therapeutic use , Retrospective Studies
2.
Cesk Slov Oftalmol ; 80(Ahead of print): 1001-1007, 2024.
Article En | MEDLINE | ID: mdl-38538290

Retinoblastoma is the most common primary malignant intraocular tumor in children. Seeding, specifically the dispersion of the tumor into the adjacent compartments, represents a major parameter determining the degree of retinoblastoma according to the International Classification of Retinoblastoma. In this article we focused on vitreous seeding, one of the main limiting factors in the successful "eye preservation treatment" of retinoblastoma. This article presents an overview of the history of vitreous seeding of retinoblastoma, established treatment procedures and new-research modalities. The introduction of systemic chemotherapy in the treatment of retinoblastoma at the end of the 1990s represented a significant breakthrough, which enabled the progressive abandonment of radiotherapy with its attendant side effects. However, the attained concentrations of chemotherapeutics in the vitreous space during systemic chemotherapy are not sufficient for the treatment of vitreous seeding, and the toxic effects of systemic chemotherapy are not negligible. A significant change came with the advent of chemotherapy in situ, with the targeted administration of chemotherapeutic drugs, namely intra-arterial and intravitreal injections, contributing to the definitive eradication of external radiotherapy and a reduction of systemic chemotherapy. Although vitreous seeding remains the most common reason for the failure of intra-arterial chemotherapy, this technique has significantly influenced the original treatment regimen of children with retinoblastoma. However, intravitreal chemotherapy has made the greatest contribution to increasing the probability of preservation of the eyeball and visual functions in patients with advanced findings. Novel local drug delivery modalities, gene therapy, oncolytic viruses and immunotherapy from several ongoing preclinical and clinical trials may represent promising approaches in the treatment of vitreous retinoblastoma seeding, though no clinical trials have yet been completed for routine use.


Retinal Neoplasms , Retinoblastoma , Child , Humans , Retinoblastoma/chemically induced , Retinoblastoma/drug therapy , Retinal Neoplasms/chemically induced , Retinal Neoplasms/drug therapy , Melphalan/adverse effects , Antineoplastic Agents, Alkylating/pharmacology , Antineoplastic Agents, Alkylating/therapeutic use , Vitreous Body/pathology , Intravitreal Injections , Retrospective Studies
3.
Environ Res ; 240(Pt 2): 117435, 2024 Jan 01.
Article En | MEDLINE | ID: mdl-37866539

BACKGROUND: Neonatal per- and polyfluoroalkyl substance (PFAS) exposure can disrupt hormonal homeostasis and induce neuro- and immunotoxicity in children. In this exploratory study, we investigated associations between PFAS levels in neonatal dried blood spots and retinoblastoma risk. MATERIALS AND METHODS: This study included 501 retinoblastoma cases born from 1983 to 2011 and 899 controls frequency-matched by birth year (20:1 matching ratio), born to 755 US-born and 366 Mexico-born mothers in California. Perfluorooctanesulfonic acid (PFOS), perflurooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) feature intensities were identified from neonatal blood spots from California newborn Genetic Disease Screening Program. Using logistic regression, we assessed whether an interquartile range (IQR) increase of PFAS levels or having above-mean levels of PFAS in blood affects retinoblastoma risk overall or its subtypes (i.e., unilateral, bilateral). We assessed children of US-born and Mexico-born mothers, separately. RESULTS AND DISCUSSION: Among all children, above-mean PFOS levels at birth increased the odds of retinoblastoma overall by 29% (95% Confidence Interval (CI): 1.00, 1.67) and unilateral retinoblastoma by 42% (95% CI: 1.03, 1.97). For children of Mexico-born mothers, we estimated the highest odds of retinoblastoma overall (adjusted odds ratio (aOR): 1.67; 95% CI: 1.06, 2.66) and bilateral retinoblastoma (aOR: 2.06; 95% CI: 1.12, 3.92) with above-mean PFOS levels. Among children of US-born mothers, higher PFOS levels increased the odds of unilateral retinoblastoma by 15% (95% CI: 0.99, 1.35) for each IQR increase and by 71% among children with above-mean PFOS levels (95% CI: 1.04, 2.90). In addition, for children of US-born mothers, PFOA increased the odds of retinoblastoma overall (aOR: 1.41; 95% CI: 1.00, 2.02 for above-mean levels, aOR: 1.06; 95% CI: 0.98, 1.16 per IQR increase). PFNA was not associated with retinoblastoma risk. CONCLUSIONS: Our results suggested that PFOS and PFOA might contribute to retinoblastoma risk in children born in California.


Fluorocarbons , Retinal Neoplasms , Retinoblastoma , Infant, Newborn , Child , Humans , Retinoblastoma/chemically induced , Retinoblastoma/epidemiology , Fluorocarbons/toxicity , Retinal Neoplasms/chemically induced , Retinal Neoplasms/epidemiology
4.
Cesk Slov Oftalmol ; 3(Ahead of Print): 1001-1014, 2023.
Article En | MEDLINE | ID: mdl-37996250

Retinoblastoma is the most common primary malignant intraocular tumor in children. Seeding, specifically the dispersion of the tumor into the adjacent compartments, represents a  major parameter determining the degree of retinoblastoma according to the International Classification of Retinoblastoma. In this article we focused on vitreous seeding, one of the main limiting factors in the successful "eye preservation treatment" of retinoblastoma. This article presents an overview of the history of vitreous seeding of retinoblastoma, established treatment procedures and new-research modalities. The introduction of systemic chemotherapy in the treatment of retinoblastoma at the end of the 1990s represented a  significant breakthrough, which enabled the progressive abandonment of radiotherapy with its attendant side effects. However, the attained concentrations of chemotherapeutics in the vitreous space during systemic chemotherapy are not sufficient for the treatment of vitreous seeding, and the toxic effects of systemic chemotherapy are not negligible. A significant change came with the advent of chemotherapy in situ, with the targeted administration of chemotherapeutic drugs, namely intra-arterial and intravitreal injections, contributing to the definitive eradication of external radiotherapy and a reduction of systemic chemotherapy. Although vitreous seeding remains the most common reason for the failure of intra-arterial chemotherapy, this technique has significantly influenced the original treatment regimen of children with retinoblastoma. However, intravitreal chemotherapy has made the greatest contribution to increasing the probability of preservation of the eyeball and visual functions in patients with advanced findings. Novel local drug delivery modalities, gene therapy, oncolytic viruses and immunotherapy from several ongoing preclinical and clinical trials may represent promising approaches in the treatment of vitreous retinoblastoma seeding, though no clinical trials have yet been completed for routine use.


Retinal Neoplasms , Retinoblastoma , Child , Humans , Antineoplastic Agents, Alkylating/therapeutic use , Intravitreal Injections , Melphalan , Retinal Neoplasms/chemically induced , Retinal Neoplasms/drug therapy , Retinoblastoma/chemically induced , Retinoblastoma/drug therapy , Retrospective Studies , Vitreous Body/pathology
5.
Lancet Child Adolesc Health ; 7(9): 613-620, 2023 09.
Article En | MEDLINE | ID: mdl-37536351

BACKGROUND: Super-selected intra-arterial chemotherapy has increasingly been used as conservative management for retinoblastoma during the past decade. However, the absence of evidence from randomised controlled trials engendered controversy in the administration route of chemotherapy. We aimed to assess the efficacy and safety of intra-arterial chemotherapy compared with intravenous chemotherapy. METHODS: This open-label, multicentre, randomised trial was done at six hospitals in China. Patients with new-onset unilateral group D or E retinoblastoma (poorly defined, large, or very large tumours, according to the International Intraocular Retinoblastoma Classification) without high-risk clinical factors were included. Patients were randomly assigned (1:1) to receive intra-arterial chemotherapy (injections of 0·5 mg/kg [or depending on age] melphalan with 20 mg carboplatin [first and third cycles] or with 1 mg topotecan [second and fourth cycles]) or intravenous chemotherapy (0·05 mg/kg [or 1·5 mg/m2] vincristine, 5 mg/kg [or 150 mg/m2] etoposide, and 18·6 mg/kg [or 560 mg/m2] carboplatin for six cycles). After intra-arterial chemotherapy, patients received a subcutaneous injection of 0·1 mL nadroparin calcium twice at a 12 h interval. Both intra-arterial and intravenous chemotherapy cycles were completed every 4 weeks. No masking was done, except of independent statisticians, who were masked to the allocation information. The primary outcome was 2-year progression-free globe salvage rate, defined as the time from randomisation to tumour progression or enucleation, whichever occurred first, and was analysed by intention to treat. We also recorded predefined safety outcomes (myelosuppression and ophthalmic arterial stenosis or occlusion) and severe adverse events likely to be related to study treatment. The study is registered with the Chinese Clinical Trial Registry, ChiCTR-IPR-15006469, and is complete. FINDINGS: Between June 1, 2015, and June 1, 2018, 234 patients with newly diagnosed retinoblastoma were screened and 143 eligible patients (median age 23·6 months [IQR 14·0-31·9]) were enrolled and randomly assigned to the intra-arterial chemotherapy group (n=72) or the intravenous chemotherapy group (n=71). At a median follow-up of 35·8 months (IQR 28·4-43·0), the 2-year progression-free globe salvage rate was 53% (38 of 72 patients) in the intra-arterial chemotherapy group and 27% (19 of 71 patients) in the intravenous chemotherapy group (risk ratio 1·97, 95% CI 1·27-3·07, p=0·0020). Myelosuppression was less common in the intra-arterial chemotherapy group than in the intravenous chemotherapy group (37 [51%] of 72 patients vs 50 [70%] of 71 patients; 0·73, 95% CI 0·56-0·96, p=0·021) and less severe (ptrend=0·0070). In the intra-arterial chemotherapy group, two (3%) of 72 patients had ophthalmic artery occlusion and 13 (18%) patients had ophthalmic artery stenosis. INTERPRETATION: Our findings show that intra-arterial chemotherapy could significantly improve the globe salvage rate in children with advanced unilateral retinoblastoma compared with intravenous chemotherapy, with mild systemic complications and no difference in overall survival rate. Intra-arterial chemotherapy could be an acceptable first-line treatment in children with advanced unilateral retinoblastoma. FUNDING: Scientific Research Program of the National Health and Family Planning Commission of China, the Clinical Research Plan of Shanghai Hospital Development Center, the National Natural Science Foundation of China, and the Science and Technology Commission of Shanghai Municipality.


Retinal Neoplasms , Retinoblastoma , Humans , Child , Infant , Child, Preschool , Retinoblastoma/drug therapy , Retinoblastoma/chemically induced , Carboplatin/adverse effects , Constriction, Pathologic/chemically induced , China , Retinal Neoplasms/drug therapy , Retinal Neoplasms/chemically induced , Randomized Controlled Trials as Topic
6.
J Hematol Oncol ; 15(1): 136, 2022 09 29.
Article En | MEDLINE | ID: mdl-36176002

Primary central nervous system lymphoma (PCNSL) is a type of central nervous system restricted non-Hodgkin lymphoma, whose histopathological diagnosis is majorly large B cell lymphoma. To provide specific, evidence-based recommendations for medical professionals and to promote more standardized, effective and safe treatment for patients with PCNSL, a panel of experts from the Chinese Neurosurgical Society of the Chinese Medical Association and the Society of Hematological Malignancies of the Chinese Anti-Cancer Association jointly developed an evidence-based consensus. After comprehensively searching literature and conducting systematic reviews, two rounds of Delphi were conducted to reach consensus on the recommendations as follows: The histopathological specimens of PCNSL patients should be obtained as safely and comprehensively as possible by multimodal tomography-guided biopsy or minimally invasive surgery. Corticosteroids should be withdrawn from, or not be administered to, patients with suspected PCNSL before biopsy if the patient's status permits. MRI (enhanced and DWI) should be performed for diagnosing and evaluating PCNSL patients where whole-body PET-CT be used at necessary time points. Mini-mental status examination can be used to assess cognitive function in the clinical management. Newly diagnosed PCNSL patients should be treated with combined high-dose methotrexate-based regimen and can be treated with a rituximab-inclusive regimen at induction therapy. Autologous stem cell transplantation can be used as a consolidation therapy. Refractory or relapsed PCNSL patients can be treated with ibrutinib with or without high-dose chemotherapy as re-induction therapy. Stereotactic radiosurgery can be used for PCNSL patients with a limited recurrent lesion who were refractory to chemotherapy and have previously received whole-brain radiotherapy. Patients with suspected primary vitreoretinal lymphoma (PVRL) should be diagnosed by vitreous biopsy. PVRL or PCNSL patients with concurrent VRL can be treated with combined systemic and local therapy.


Central Nervous System Neoplasms , Hematopoietic Stem Cell Transplantation , Lymphoma, Non-Hodgkin , Retinal Neoplasms , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Central Nervous System/pathology , Central Nervous System Neoplasms/diagnosis , Central Nervous System Neoplasms/therapy , Consensus , Humans , Lymphoma, Non-Hodgkin/drug therapy , Methotrexate/therapeutic use , Positron Emission Tomography Computed Tomography , Retinal Neoplasms/chemically induced , Retinal Neoplasms/drug therapy , Rituximab/adverse effects , Transplantation, Autologous , Vitreous Body/pathology
7.
Int J Hyg Environ Health ; 245: 114025, 2022 08.
Article En | MEDLINE | ID: mdl-36037576

BACKGROUND: Retinoblastoma is a rare tumor of the retina, most commonly found in young children. Due to the rarity of this childhood cancer, few studies have been able to examine prenatal pesticide exposure as a risk factor. OBJECTIVE: To examine the relationship between childhood retinoblastoma and prenatal exposure to pesticides through residential proximity to agricultural pesticide applications. METHODS: We conducted a population-based case-control study using cases aged 5 and younger identified from the California Cancer Registry, and controls randomly selected from California birth certificates. Frequency matching cases to controls by age resulted in 221 cases of unilateral retinoblastoma and 114 cases of bilateral retinoblastoma, totaling 335 cases and 123,166 controls. Based on addresses from birth certificates we employed Pesticide Use Reports and land use information within a geographic information system approach to individually assess exposures to specific pesticides within 4000 m of the residence reported on birth certificates. The associations between retinoblastoma (all types combined and stratified by laterality) and individual pesticides were expressed as odds ratios estimates obtained from unconditional logistic regression models including a single pesticide, and from a hierarchical logistic regression model including all pesticides. RESULTS: We found that exposures to acephate (OR: 1.70, 95% CI: 1.20, 2.41) and bromacil (OR: 1.87, 95% CI: 1.07, 3.26) were associated with increased risk for unilateral retinoblastoma. In addition to acephate, we found that pymetrozine (OR: 1.45, 95% CI: 1.00, 2.08) and kresoxim-methyl (OR: 1.60, 95% CI: 1.00, 2.56) were associated with retinoblastoma (all types combined). CONCLUSION: Our findings suggest that certain types of prenatal ambient pesticide exposure from residing near agricultural fields may play a role in the development of childhood retinoblastoma.


Pesticides , Prenatal Exposure Delayed Effects , Retinal Neoplasms , Retinoblastoma , California/epidemiology , Case-Control Studies , Child , Child, Preschool , Environmental Exposure/adverse effects , Female , Humans , Pesticides/adverse effects , Pregnancy , Prenatal Exposure Delayed Effects/chemically induced , Prenatal Exposure Delayed Effects/epidemiology , Retinal Neoplasms/chemically induced , Retinal Neoplasms/epidemiology , Retinoblastoma/chemically induced , Retinoblastoma/epidemiology
8.
Cesk Slov Oftalmol ; 78(3): 112-120, 2022.
Article En | MEDLINE | ID: mdl-35760582

AIM: This study aimed to determine the effects of a single intravitreal ranibizumab injection in rabbits induced with retinoblastoma (RB). MATERIAL AND METHODS: RB was induced in six New Zealand white rabbits by subretinal injection of a cultured WERI-RBb-1 cell line into the right eye. After six weeks, Group A (n = 3) was given intravitreal ranibizumab injection (0.3mg in 0.03ml) and Group B (n = 3) was the control. Baseline and serial clinical examinations were performed on days 1, 3, 6, 12, 15, 18 and 21. The right eyes were enucleated for both groups on day 21 for histopathological examination. RESULTS: The rabbits in both groups developed intraocular lesions which was detectable clinically at one-week post-tumor inoculation. The tumor grew slowly without spontaneous regression. After the animals in Group A were given an intravitreal ranibizumab injection, regression of the tumor was detected clinically, while the tumor in Group B continued to grow slowly. Histopathological findings confirmed the presence of a tumor that closely resembled features of poorly differentiated human RB cells. At the end of 21 days, the size of the tumor was larger in Group B in comparison to Group A. However, the treated group also developed a focal area of retinal hyperplasia. There was no significant side effect of ranibizumab injection except temporary high intraocular pressure immediately post-injection, which was relieved after paracentesis. CONCLUSIONS: Intravitreal ranibizumab is a potential treatment for RB. It is an effective therapy with a tolerable safety profile in this animal experimental study.


Retinal Neoplasms , Retinoblastoma , Angiogenesis Inhibitors/pharmacology , Animals , Humans , Intravitreal Injections , Rabbits , Ranibizumab/therapeutic use , Retinal Neoplasms/chemically induced , Retinal Neoplasms/drug therapy , Retinoblastoma/chemically induced , Retinoblastoma/drug therapy , Vascular Endothelial Growth Factor A
9.
Occup Environ Med ; 75(3): 205-211, 2018 03.
Article En | MEDLINE | ID: mdl-29074554

OBJECTIVES: We examined associations between parental occupational chemical exposures up to 10 years before conception and the risk of sporadic retinoblastoma among offspring. METHODS: In our multicentre study on non-familial retinoblastoma, parents of 187 unilateral and 95 bilateral cases and 155 friend controls were interviewed by telephone. Exposure information was collected retroactively through a detailed occupational questionnaire that asked fathers to report every job held in the 10 years before conception, and mothers 1 month before and during the index pregnancy. An industrial hygienist reviewed all occupational data and assigned an overall exposure score to each job indicating the presence of nine hazardous agents. RESULTS: We estimated elevated ORs for unilateral and bilateral retinoblastoma among offspring of fathers who were exposed to polycyclic aromatic hydrocarbons or paints in the 10 years before conception. However, only for exposure to paints did confidence limits exclude the null for bilateral disease (OR: 8.76, 95% CI: 1.32 to 58.09). Maternal prenatal exposure to at least one of the nine agents was related to increased risk of unilateral disease in their children (OR: 5.25, 95% CI: 1.14 to 24.16). Fathers exposed to at least one of the nine agents and who were ≥30 years of age were at increased risk of having a child diagnosed with bilateral retinoblastoma (OR: 6.59, 95% CI: 1.34 to 32.42). CONCLUSIONS: Our results suggest a role for several hazardous occupational exposures in the development of childhood retinoblastoma.


Occupational Exposure/adverse effects , Parents , Prenatal Exposure Delayed Effects/chemically induced , Retinal Neoplasms/chemically induced , Retinoblastoma/chemically induced , Adult , Case-Control Studies , Child , Fathers/statistics & numerical data , Female , Humans , Male , Mothers/statistics & numerical data , Occupational Exposure/statistics & numerical data , Pregnancy , Prenatal Exposure Delayed Effects/epidemiology , Retinal Neoplasms/epidemiology , Retinoblastoma/epidemiology , Risk Factors , Young Adult
10.
Am J Ophthalmol ; 176: 166-173, 2017 Apr.
Article En | MEDLINE | ID: mdl-28131887

PURPOSE: To examine whether parental pesticide exposure contributes to the development of sporadic retinoblastoma. DESIGN: Case-control study. METHODS: Data were collected by a large multicenter study of sporadic retinoblastoma in which parents of 99 unilateral and 56 bilateral age-matched case-control pairs were interviewed by telephone. Retrospective exposure information was collected on the type, location, timing, and frequency of residential pesticide use. We used conditional logistic regression analyses to estimate odds ratios for maternal pesticide exposure in the month before or during pregnancy and to assess whether the type of product, and the circumstances under which it was applied, were associated with risk of disease. RESULTS: Unilateral retinoblastoma was associated with parental insecticide use (odds ratio [OR], 2.8; confidence interval [CI], 1.1-6.7) and the use of professional lawn or landscape services (OR, 2.8; CI, 1.0-8.2). For bilateral disease we observed large point estimates for several exposures but the small number of cases rendered these results uninformative (ie, resulted in wide confidence intervals). Whether parents used the pesticide inside vs outside the home did not appear to modify risk estimates for unilateral retinoblastoma (OR, 2.5; CI, 0.9-7.0 vs OR, 2.5; CI, 1.0-6.5), nor did the type, frequency, timing related to pregnancy, or applicator of pesticide used influence estimates to an appreciable degree for disease. CONCLUSIONS: Our results suggest that parental pesticide exposure before or during pregnancy may play a role in the development of childhood retinoblastoma. Retrospectively collected exposure data introduces the possibility of recall bias; therefore, results should be interpreted cautiously until additional studies are conducted.


Environmental Exposure/adverse effects , Maternal Exposure/adverse effects , Pesticides/adverse effects , Retinal Neoplasms/chemically induced , Retinoblastoma/chemically induced , Adolescent , Adult , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Male , Pregnancy , Prenatal Exposure Delayed Effects , Prospective Studies , Retinal Neoplasms/diagnosis , Retinoblastoma/diagnosis , Risk Factors
12.
Can J Ophthalmol ; 40(5): 585-92, 2005 Oct.
Article En | MEDLINE | ID: mdl-16391621

CASE REPORT: Primary intraocular lymphoma arose over a period of 9 months in the left eye of an 81-year-old woman who was blind in both eyes from temporal arteritis. During this period, she was treated with prednisone and methotrexate. Following a sudden total hyphema, the eye was enucleated. Examination revealed that, in addition to iris neovascularisation and central retinal artery occlusion, the neurosensory retina was replaced by atypical lymphocytes. COMMENTS: Histological and immunohistochemical studies confirmed the presence of a lymphoma with features indicative of an immunosuppression-related disorder. The relationship of the lymphoma to the vascular changes within the eye is discussed.


Giant Cell Arteritis/drug therapy , Immunosuppressive Agents/adverse effects , Lymphoma, B-Cell/chemically induced , Methotrexate/adverse effects , Retinal Neoplasms/chemically induced , Aged, 80 and over , Biomarkers, Tumor/metabolism , Biopsy , Eye Enucleation , Female , Giant Cell Arteritis/pathology , Humans , Immunohistochemistry , Lymphoma, B-Cell/metabolism , Lymphoma, B-Cell/pathology , Retinal Neoplasms/metabolism , Retinal Neoplasms/pathology
13.
Lab Invest ; 81(9): 1191-8, 2001 Sep.
Article En | MEDLINE | ID: mdl-11555667

Interspecific hybrid crosses between members of the fish genus Xiphophorus have been used for over 70 years to study the genetic aspects of melanoma formation. In the well-established "Gordon-Kosswig" cross, the platyfish X. maculatus is outcrossed to the swordtail X. helleri, and the resulting backcross segregants spontaneously develop melanoma. We recently produced a distinct cross between X. maculatus and another platyfish species, X. couchianus. X. maculatus strain Jp 163 A is homozygous for several X-linked pigment pattern genes, including the Spotted dorsal (Sd), Dorsal red (Dr), and Anal fin spot (Af). Af is a sex-limited trait, coding exclusively for melanophores distributed on the modified anal fin or "gonopodium" in the adult male fish. Within F1 and BC1 hybrids (to X. couchianus), the Sd pigment pattern is phenotypically suppressed, whereas Dr and Af are enhanced. We exposed BC1 hybrids to the direct-acting carcinogen N-methyl-N-nitrosourea (MNU). Treatment led to the development of schwannomas, fibrosarcomas, and retinoblastomas. In addition, numerous MNU-treated males that inherited Af developed a pronounced melanotic phenotype, with melanin-containing cells oftentimes totally covering the gonopodium and extending further to grow within the ventral regions of the fish. Genetic linkage analysis of the BC1 hybrids revealed a significant (p < 0.01) association between CDKN2X genotype and the phenotypic degree of melanization. Such an association is consistent with a locus within linkage group V playing a role in the development of melanosis and delineates three genetic preconditions and a carcinogenic scheme resulting in melanosis of the ventral regions of hybrid fish. The overall study further alludes to the potential of using Xiphophorus fish to study carcinogenic mechanisms for tumors other than melanoma (schwannoma, fibrosarcoma, and retinoblastoma) and should enable extensive pathologic and molecular genetic studies of derived neoplastic abnormalities.


Alkylating Agents , Fibrosarcoma/chemically induced , Methylnitrosourea , Nervous System Neoplasms/chemically induced , Neurilemmoma/chemically induced , Retinal Neoplasms/chemically induced , Retinoblastoma/chemically induced , Animals , Female , Fibrosarcoma/pathology , Fishes/genetics , Genetic Linkage , Genotype , Hybridization, Genetic , Male , Melanosis/chemically induced , Melanosis/genetics , Nervous System Neoplasms/pathology , Neurilemmoma/pathology , Retinal Neoplasms/pathology , Retinoblastoma/pathology
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