RARE DISEASE
Waardenburg syndrome type 3
Waardenburg syndrome type 3
Waardenburg syndrome type 3
Synonyms: Klein-Waardenburg syndrome, WS3, Waardenburg syndrome type III, Waardenburg syndrome with limb anomalies
Synonyms: Klein-Waardenburg syndrome, WS3, Waardenburg syndrome type III, Waardenburg syndrome with limb anomalies
Synonyms: Klein-Waardenburg syndrome, WS3, Waardenburg syndrome type III, Waardenburg syndrome with limb anomalies
Drug discovery
60
papers
On emerging therapies
Overview
Waardenburg Syndrome Type 3 (WS3) is a rare genetic disorder characterized by congenital sensorineural hearing loss, pigmentary abnormalities (e.g., heterochromia iridis, white forelock), dystopia canthorum, and musculoskeletal anomalies such as hypoplastic limbs, joint contractures, and syndactyly. Caused by PAX3 gene mutations, it follows autosomal dominant inheritance, though homozygous cases show more severe phenotypes [1][2][7][11].
Therapies
Hearing management: Cochlear implants or hearing aids for sensorineural deficits [1][3].
Musculoskeletal support: Physiotherapy, orthopedic surgery for limb contractures [2][6].
Pigmentation/psychosocial care: Sun protection for hypopigmented skin; cognitive behavioral therapy for self-esteem [3][15].
Categories: rare developmental anomalies during embryogenesis, rare genetic diseases, rare ophthalmic disorders, rare otorhinolaryngological diseases, rare skin diseases
Research Papers
60 drug discovery papers about Waardenburg syndrome type 3. Recent publications:
60 drug discovery papers about Waardenburg syndrome type 3. Recent publications:
categories:
Small molecules
gene therapies
2026-05-27 | Molecular Characterization of Syndromic Hearing Loss in North African Moroccan Families.
Hearing loss (HL) is a common sensory disorder, with syndromic forms accounting for ~30% of genetic cases. Due to phenotypic and genetic heterogeneity, accurate diagnosis remains challenging. Exome sequencing (ES) offers a powerful tool to uncover the underlying genetic causes. This study aimed to investigate the genetic basis of syndromic hearing loss (SHL) in North African Moroccan patients through ES. Seven individuals with suspected SHL were recruited from Hassan II University Hospital, Fez. After clinical and audiological assessments, ES was performed to identify causal genetic variants. Two of the participating individuals had Usher syndrome, and one each had Cornelia de Lange syndrome, Wolfram syndrome, Jervell and Lange-Nielsen syndrome, CHARGE syndrome, and Waardenburg syndrome. The causes of all these syndromes were determined, with pathogenic variants in MYO7A, USH1G, SMC1A, WFS1, KCNQ1, CHD7, and MITF. Across the combined cohort of reported Moroccan SHL cases, variants in CHD7 and MYO7A were among the most frequently observed, while USH1G and MITF variants were rare. This study enhances the understanding of SHL in North Africa, revealing a high level of locus and allelic heterogeneity. Examining disparate populations yields novel insights into the etiology of SHL, which can subsequently enhance genetic diagnosis and tailored management strategies.
2024-12-12 | Audiologic Outcomes After Cochlear Implantation in Prelingually Deaf Children Who Have Combined Anomalies or Disabilities.
To evaluate the audiologic outcomes after cochlear implantation (CI) in prelingually deaf children with comorbid disorders. Retrospective study. Tertiary care academic center. We enrolled 85 deaf children (111 ears) with comorbid disorders who underwent CI surgery. We selected the most common comorbid disorder and compared the categories of auditory performance (CAP) scores of each comorbidity group with those of the control group. Combined cochlear anomalies were also evaluated using temporal bone computed tomography. The most common comorbid disorder was CHARGE syndrome (n = 17), followed by developmental delay (n = 13), valvular heart disease (including septal defect) (n = 13), Waardenburg syndrome (n = 8), Down syndrome (n = 6), cerebral palsy (n = 5), and cryptorchidism (n = 5). The CAP scores differed significantly between all the groups and the control group after 6 months (p < 0.001). The differences in the CHARGE syndrome (p = 0.004), cerebral palsy (p = 0.001), and Down syndrome (p = 0.004) groups remained significant 2 years after CI. When comparing the presence or absence of anomalies within the syndromic and nonsyndromic groups, significantly poorer outcomes exist when cochlear anomalies with absent modiolus or cochlear nerve deficits were observed, regardless of the presence of syndromic disorders. Compared with those in the control group, the CAP scores in the group with coexisting disabilities increased over time, but their final scores were relatively lower. Combined disabilities as well as the absent modiolus and cochlear nerve deficit may be clinical markers for poor CAP scores.
2023-04-04 | Identification of two variants in PAX3 and FBN1 in a Chinese family with Waardenburg and Marfan syndrome via whole exome sequencing.
Both Warrensburg (WS) and Marfan syndrome (MFS) can impair the vision. Here, we recruited a Chinese family consisting of two WS affected individuals (II:1 and III:3) and five MFS affected individuals( I:1, II:2, III:1, III:2, and III:5) as well as one suspected MFS individual (II:4). Using whole exome sequencing (WES) and subsequent PCR-Sanger sequencing, we identified one novel heterozygous variant NM_000438 (PAX3) c.208 T > C, (p.Cys70Arg) from individuals with WS and one previous reported variant NM_000138 (FBN1) c.2740 T > A, (p.Cys914Ser) from individuals with MFS and co-segregated with the diseases. Real-time PCR and Western blot assay showed that, compared to their wild-type, both mRNAs and proteins of PAX3 and FBN1 mutants reduced in HKE293T cells. Together, our study identified two disease-causing variants in a same Chinese family with WS and MFS, and confirmed their damaged effects on their genes' expression. Therefore, those findings expand the mutation spectrum of PAX3 and provide a new perspective for the potential therapy.
2022-09-20 | Genetic insights, disease mechanisms, and biological therapeutics for Waardenburg syndrome.
Waardenburg syndrome (WS), also known as auditory-pigmentary syndrome, is the most common cause of syndromic hearing loss (HL), which accounts for approximately 2-5% of all patients with congenital hearing loss. WS is classified into four subtypes depending on the clinical phenotypes. Currently, pathogenic mutations of PAX3, MITF, SOX10, EDN3, EDNRB or SNAI2 are associated with different subtypes of WS. Although supportive techniques like hearing aids, cochlear implants, or other assistive listening devices can alleviate the HL symptom, there is no cure for WS to date. Recently major progress has been achieved in preclinical studies of genetic HL in animal models, including gene delivery and stem cell replacement therapies. This review focuses on the current understandings of pathogenic mechanisms and potential biological therapeutic approaches for HL in WS, providing strategies and directions for implementing WS biological therapies, as well as possible problems to be faced, in the future.
2011-10-14 | FGF2 regulates melanocytes viability through the STAT3-transactivated PAX3 transcription
PAX3 (paired box 3) is known to have an important role in melanocyte development through modulation of microphthalmia-associated transcription factor transcription. Here we found that PAX3 transcriptional activity could be regulated through FGF2 (basic fibroblast growth factor)-STAT3 (signal transducer and activator of transcription 3) signaling in the pigment cells. To study its function in vivo, we have generated a transgenic mouse model expressing PAX3 driven by tyrosinase promoter in a tissue-specific fashion. These animals exhibit hyperpigmentation in the epidermis, evident in the skin color of their ears and tails. We showed that the darker skin color results from both increased melanocyte numbers and melanin synthesis. Together, our study delineated a novel pathway in the melanocyte lineage, linking FGF2-STAT3 signaling to increased PAX3 transcription. Moreover, our results suggest that this pathway might contribute to the regulation of melanocyte numbers and melanin levels, and thereby provide an alternative strategy to induce pigmentation.
small molecules
2026-02-13 | SOX10 Mutation of Waardenburg Syndrome With Hypogonadism: A Report of 2 Cases.
Waardenburg syndrome (WS) is a complex genetic disorder primarily characterized by auditory and pigmentary abnormalities, resulting from neural crest cell migration disorders. We reported 2 genetically confirmed SOX10-mutant WS cases illustrating critical management principles. Both patients underwent early auditory intervention (case 1: cochlear implantation at age 3; case 2: hearing aids from age 2), resulting in preserved age-appropriate language acquisition. Each case manifested delayed puberty with biochemical evidence of hypogonadotropic hypogonadism, necessitating gonadotropin therapy to potentiate virilization and preserve fertility. Multidisciplinary care and emerging therapeutic approaches offer hope for better management. Further studies are warranted to improve the diagnosis, treatment, and quality of life of patients with WS.
2025-06-25 | [Mechanisms of enhanced noise susceptibility in waardenburg syndrome Sox10 p.S100Rfs*9 mutant mice].
Objective:To investigate the impact of Waardenburg syndrome（WS） -associated Sox10 p.S100Rfs*9 mutation on inner ear function and its mechanism in noise-induced hearing impairment. Methods:A mice model carrying the Sox10 p.S100Rfs*9 mutation was established using CRISPR-Cas9 gene editing technology. Auditory phenotypes were assessed under baseline conditions and after noise exposure（96 dB SPL, 2 hours）. Auditory brainstem response（ABR） tests were performed to evaluate hearing function, combined with immunofluorescence staining of cochlear basilar membrane whole-mounts to observe hair cells and ribbon synapses. Transcriptome sequencing was conducted to analyze molecular mechanisms. Results:Sox10 p.S100Rfs*9 heterozygous mice exhibited normal hearing thresholds with characteristic ventral pigmentation abnormalities under baseline conditions. Following noise exposure, mutant mice showed significantly higher ABR thresholds at 24 000 Hz compared to wild-type controls（[60.00±6.12]vs[48.13±4.28]dB SPL, P<0.000 1）, and a significant reduction in ribbon synapses（CtBP2-positive puncta） in the basal turn（[55.0±2.3]vs[64.8±3.3]per inner hair cell, P=0.006 6）, while hair cell morphology and number remained intact. Transcriptome analysis revealed altered expression of genes involved in immune regulation, membrane structures, ion channels, and neuroactive ligand-receptor interactions. Conclusion:The Sox10 p.S100Rfs*9 mutation does not alter baseline hearing function but significantly increases inner ear susceptibility to noise damage, primarily manifested as enhanced ribbon synapse vulnerability, especially in high-frequency regions. This gene-environment interaction reveals that Sox10 haploinsufficiency may compromise noise tolerance by affecting synaptic stability and inner ear protective mechanisms. These findings provide new perspectives on the phenotypic heterogeneity in WS patients and theoretical basis for individualized noise protection strategies for patients carrying SOX10 mutations.
2025-05-05 | Congenital Localized Hypopigmentation Disorders as a Clue of Severe Neurologic Involvement: An Update Review.
In clinical practice, cutaneous disorders associated with neurologic involvement are relatively common, as both cutaneous and systems often originate from similar or synchronous embryonic mechanisms. Cutaneous hypopigmentation includes a wide range of disorders that can be categorized congenital and acquired based on the onset, and as localized and generalized types, depending on their skin distribution. Although cutaneous hypopigmentation may appear as a benign clinical manifestation, its association with neurologic or others systemic involvement can indicate more severe underlying disorders. This literature review focuses on congenital localized types of cutaneous hypopigmentation that are classically linked to neurologic impairment. Four congenital disorders were highlighted for their characteristic presentation of localized cutaneous hypopigmentation and neurologic involvement: Waardenburg syndrome, incontinentia pigmenti, hypomelanosis of Ito, and tuberous sclerosis complex.Clinical and genetic findings for these conditions were reviewed and updated, with an emphasis on the cutaneous manifestations, associated systemic anomalies, and neurologic involvement. Established diagnostic criteria and emerging trends in therapeutic approaches were also explored. Promising results, particularly the use of mammalian target of rapamycin (mTOR) in the treatment of tuberous sclerosis complex, highlight the potential for improved outcomes. Early diagnosis, rapid treatment, and innovative therapies may play a crucial role in positively altering the clinical course of these disorders.
2024-02-28 | Readthrough Activators and Nonsense-Mediated mRNA Decay Inhibitor Molecules: Real Potential in Many Genetic Diseases Harboring Premature Termination Codons
Nonsense mutations that generate a premature termination codon (PTC) can induce both the accelerated degradation of mutated mRNA compared with the wild type version of the mRNA or the production of a truncated protein. One of the considered therapeutic strategies to bypass PTCs is their “readthrough” based on small-molecule drugs. These molecules promote the incorporation of a near-cognate tRNA at the PTC position through the native polypeptide chain. In this review, we detailed the various existing strategies organized according to pharmacological molecule types through their different mechanisms. The positive results that followed readthrough molecule testing in multiple neuromuscular disorder models indicate the potential of this approach in peripheral neuropathies.
2023-01-05 | A unique hyperdynamic dimer interface permits small molecule perturbation of the melanoma oncoprotein MITF for melanoma therapy.
Microphthalmia transcription factor (MITF) regulates melanocyte development and is the "lineage-specific survival" oncogene of melanoma. MITF is essential for melanoma initiation, progression, and relapse and has been considered an important therapeutic target; however, direct inhibition of MITF through small molecules is considered impossible, due to the absence of a ligand-binding pocket for drug design. Here, our structural analyses show that the structure of MITF is hyperdynamic because of its out-of-register leucine zipper with a 3-residue insertion. The dynamic MITF is highly vulnerable to dimer-disrupting mutations, as we observed that MITF loss-of-function mutations in human Waardenburg syndrome type 2 A are frequently located on the dimer interface and disrupt the dimer forming ability accordingly. These observations suggest a unique opportunity to inhibit MITF with small molecules capable of disrupting the MITF dimer. From a high throughput screening against 654,650 compounds, we discovered compound TT-012, which specifically binds to dynamic MITF and destroys the latter's dimer formation and DNA-binding ability. Using chromatin immunoprecipitation assay and RNA sequencing, we showed that TT-012 inhibits the transcriptional activity of MITF in B16F10 melanoma cells. In addition, TT-012 inhibits the growth of high-MITF melanoma cells, and inhibits the tumor growth and metastasis with tolerable toxicity to liver and immune cells in animal models. Together, this study demonstrates a unique hyperdynamic dimer interface in melanoma oncoprotein MITF, and reveals a novel approach to therapeutically suppress MITF activity.
gene therapies
2026-05-27 | Molecular Characterization of Syndromic Hearing Loss in North African Moroccan Families.
Hearing loss (HL) is a common sensory disorder, with syndromic forms accounting for ~30% of genetic cases. Due to phenotypic and genetic heterogeneity, accurate diagnosis remains challenging. Exome sequencing (ES) offers a powerful tool to uncover the underlying genetic causes. This study aimed to investigate the genetic basis of syndromic hearing loss (SHL) in North African Moroccan patients through ES. Seven individuals with suspected SHL were recruited from Hassan II University Hospital, Fez. After clinical and audiological assessments, ES was performed to identify causal genetic variants. Two of the participating individuals had Usher syndrome, and one each had Cornelia de Lange syndrome, Wolfram syndrome, Jervell and Lange-Nielsen syndrome, CHARGE syndrome, and Waardenburg syndrome. The causes of all these syndromes were determined, with pathogenic variants in MYO7A, USH1G, SMC1A, WFS1, KCNQ1, CHD7, and MITF. Across the combined cohort of reported Moroccan SHL cases, variants in CHD7 and MYO7A were among the most frequently observed, while USH1G and MITF variants were rare. This study enhances the understanding of SHL in North Africa, revealing a high level of locus and allelic heterogeneity. Examining disparate populations yields novel insights into the etiology of SHL, which can subsequently enhance genetic diagnosis and tailored management strategies.
2024-12-12 | Audiologic Outcomes After Cochlear Implantation in Prelingually Deaf Children Who Have Combined Anomalies or Disabilities.
To evaluate the audiologic outcomes after cochlear implantation (CI) in prelingually deaf children with comorbid disorders. Retrospective study. Tertiary care academic center. We enrolled 85 deaf children (111 ears) with comorbid disorders who underwent CI surgery. We selected the most common comorbid disorder and compared the categories of auditory performance (CAP) scores of each comorbidity group with those of the control group. Combined cochlear anomalies were also evaluated using temporal bone computed tomography. The most common comorbid disorder was CHARGE syndrome (n = 17), followed by developmental delay (n = 13), valvular heart disease (including septal defect) (n = 13), Waardenburg syndrome (n = 8), Down syndrome (n = 6), cerebral palsy (n = 5), and cryptorchidism (n = 5). The CAP scores differed significantly between all the groups and the control group after 6 months (p < 0.001). The differences in the CHARGE syndrome (p = 0.004), cerebral palsy (p = 0.001), and Down syndrome (p = 0.004) groups remained significant 2 years after CI. When comparing the presence or absence of anomalies within the syndromic and nonsyndromic groups, significantly poorer outcomes exist when cochlear anomalies with absent modiolus or cochlear nerve deficits were observed, regardless of the presence of syndromic disorders. Compared with those in the control group, the CAP scores in the group with coexisting disabilities increased over time, but their final scores were relatively lower. Combined disabilities as well as the absent modiolus and cochlear nerve deficit may be clinical markers for poor CAP scores.
2023-04-04 | Identification of two variants in PAX3 and FBN1 in a Chinese family with Waardenburg and Marfan syndrome via whole exome sequencing.
Both Warrensburg (WS) and Marfan syndrome (MFS) can impair the vision. Here, we recruited a Chinese family consisting of two WS affected individuals (II:1 and III:3) and five MFS affected individuals( I:1, II:2, III:1, III:2, and III:5) as well as one suspected MFS individual (II:4). Using whole exome sequencing (WES) and subsequent PCR-Sanger sequencing, we identified one novel heterozygous variant NM_000438 (PAX3) c.208 T > C, (p.Cys70Arg) from individuals with WS and one previous reported variant NM_000138 (FBN1) c.2740 T > A, (p.Cys914Ser) from individuals with MFS and co-segregated with the diseases. Real-time PCR and Western blot assay showed that, compared to their wild-type, both mRNAs and proteins of PAX3 and FBN1 mutants reduced in HKE293T cells. Together, our study identified two disease-causing variants in a same Chinese family with WS and MFS, and confirmed their damaged effects on their genes' expression. Therefore, those findings expand the mutation spectrum of PAX3 and provide a new perspective for the potential therapy.
2022-09-20 | Genetic insights, disease mechanisms, and biological therapeutics for Waardenburg syndrome.
Waardenburg syndrome (WS), also known as auditory-pigmentary syndrome, is the most common cause of syndromic hearing loss (HL), which accounts for approximately 2-5% of all patients with congenital hearing loss. WS is classified into four subtypes depending on the clinical phenotypes. Currently, pathogenic mutations of PAX3, MITF, SOX10, EDN3, EDNRB or SNAI2 are associated with different subtypes of WS. Although supportive techniques like hearing aids, cochlear implants, or other assistive listening devices can alleviate the HL symptom, there is no cure for WS to date. Recently major progress has been achieved in preclinical studies of genetic HL in animal models, including gene delivery and stem cell replacement therapies. This review focuses on the current understandings of pathogenic mechanisms and potential biological therapeutic approaches for HL in WS, providing strategies and directions for implementing WS biological therapies, as well as possible problems to be faced, in the future.
2011-10-14 | FGF2 regulates melanocytes viability through the STAT3-transactivated PAX3 transcription
PAX3 (paired box 3) is known to have an important role in melanocyte development through modulation of microphthalmia-associated transcription factor transcription. Here we found that PAX3 transcriptional activity could be regulated through FGF2 (basic fibroblast growth factor)-STAT3 (signal transducer and activator of transcription 3) signaling in the pigment cells. To study its function in vivo, we have generated a transgenic mouse model expressing PAX3 driven by tyrosinase promoter in a tissue-specific fashion. These animals exhibit hyperpigmentation in the epidermis, evident in the skin color of their ears and tails. We showed that the darker skin color results from both increased melanocyte numbers and melanin synthesis. Together, our study delineated a novel pathway in the melanocyte lineage, linking FGF2-STAT3 signaling to increased PAX3 transcription. Moreover, our results suggest that this pathway might contribute to the regulation of melanocyte numbers and melanin levels, and thereby provide an alternative strategy to induce pigmentation.
small molecules
2026-02-13 | SOX10 Mutation of Waardenburg Syndrome With Hypogonadism: A Report of 2 Cases.
Waardenburg syndrome (WS) is a complex genetic disorder primarily characterized by auditory and pigmentary abnormalities, resulting from neural crest cell migration disorders. We reported 2 genetically confirmed SOX10-mutant WS cases illustrating critical management principles. Both patients underwent early auditory intervention (case 1: cochlear implantation at age 3; case 2: hearing aids from age 2), resulting in preserved age-appropriate language acquisition. Each case manifested delayed puberty with biochemical evidence of hypogonadotropic hypogonadism, necessitating gonadotropin therapy to potentiate virilization and preserve fertility. Multidisciplinary care and emerging therapeutic approaches offer hope for better management. Further studies are warranted to improve the diagnosis, treatment, and quality of life of patients with WS.
2025-06-25 | [Mechanisms of enhanced noise susceptibility in waardenburg syndrome Sox10 p.S100Rfs*9 mutant mice].
Objective:To investigate the impact of Waardenburg syndrome（WS） -associated Sox10 p.S100Rfs*9 mutation on inner ear function and its mechanism in noise-induced hearing impairment. Methods:A mice model carrying the Sox10 p.S100Rfs*9 mutation was established using CRISPR-Cas9 gene editing technology. Auditory phenotypes were assessed under baseline conditions and after noise exposure（96 dB SPL, 2 hours）. Auditory brainstem response（ABR） tests were performed to evaluate hearing function, combined with immunofluorescence staining of cochlear basilar membrane whole-mounts to observe hair cells and ribbon synapses. Transcriptome sequencing was conducted to analyze molecular mechanisms. Results:Sox10 p.S100Rfs*9 heterozygous mice exhibited normal hearing thresholds with characteristic ventral pigmentation abnormalities under baseline conditions. Following noise exposure, mutant mice showed significantly higher ABR thresholds at 24 000 Hz compared to wild-type controls（[60.00±6.12]vs[48.13±4.28]dB SPL, P<0.000 1）, and a significant reduction in ribbon synapses（CtBP2-positive puncta） in the basal turn（[55.0±2.3]vs[64.8±3.3]per inner hair cell, P=0.006 6）, while hair cell morphology and number remained intact. Transcriptome analysis revealed altered expression of genes involved in immune regulation, membrane structures, ion channels, and neuroactive ligand-receptor interactions. Conclusion:The Sox10 p.S100Rfs*9 mutation does not alter baseline hearing function but significantly increases inner ear susceptibility to noise damage, primarily manifested as enhanced ribbon synapse vulnerability, especially in high-frequency regions. This gene-environment interaction reveals that Sox10 haploinsufficiency may compromise noise tolerance by affecting synaptic stability and inner ear protective mechanisms. These findings provide new perspectives on the phenotypic heterogeneity in WS patients and theoretical basis for individualized noise protection strategies for patients carrying SOX10 mutations.
2025-05-05 | Congenital Localized Hypopigmentation Disorders as a Clue of Severe Neurologic Involvement: An Update Review.
In clinical practice, cutaneous disorders associated with neurologic involvement are relatively common, as both cutaneous and systems often originate from similar or synchronous embryonic mechanisms. Cutaneous hypopigmentation includes a wide range of disorders that can be categorized congenital and acquired based on the onset, and as localized and generalized types, depending on their skin distribution. Although cutaneous hypopigmentation may appear as a benign clinical manifestation, its association with neurologic or others systemic involvement can indicate more severe underlying disorders. This literature review focuses on congenital localized types of cutaneous hypopigmentation that are classically linked to neurologic impairment. Four congenital disorders were highlighted for their characteristic presentation of localized cutaneous hypopigmentation and neurologic involvement: Waardenburg syndrome, incontinentia pigmenti, hypomelanosis of Ito, and tuberous sclerosis complex.Clinical and genetic findings for these conditions were reviewed and updated, with an emphasis on the cutaneous manifestations, associated systemic anomalies, and neurologic involvement. Established diagnostic criteria and emerging trends in therapeutic approaches were also explored. Promising results, particularly the use of mammalian target of rapamycin (mTOR) in the treatment of tuberous sclerosis complex, highlight the potential for improved outcomes. Early diagnosis, rapid treatment, and innovative therapies may play a crucial role in positively altering the clinical course of these disorders.
2024-02-28 | Readthrough Activators and Nonsense-Mediated mRNA Decay Inhibitor Molecules: Real Potential in Many Genetic Diseases Harboring Premature Termination Codons
Nonsense mutations that generate a premature termination codon (PTC) can induce both the accelerated degradation of mutated mRNA compared with the wild type version of the mRNA or the production of a truncated protein. One of the considered therapeutic strategies to bypass PTCs is their “readthrough” based on small-molecule drugs. These molecules promote the incorporation of a near-cognate tRNA at the PTC position through the native polypeptide chain. In this review, we detailed the various existing strategies organized according to pharmacological molecule types through their different mechanisms. The positive results that followed readthrough molecule testing in multiple neuromuscular disorder models indicate the potential of this approach in peripheral neuropathies.
2023-01-05 | A unique hyperdynamic dimer interface permits small molecule perturbation of the melanoma oncoprotein MITF for melanoma therapy.
Microphthalmia transcription factor (MITF) regulates melanocyte development and is the "lineage-specific survival" oncogene of melanoma. MITF is essential for melanoma initiation, progression, and relapse and has been considered an important therapeutic target; however, direct inhibition of MITF through small molecules is considered impossible, due to the absence of a ligand-binding pocket for drug design. Here, our structural analyses show that the structure of MITF is hyperdynamic because of its out-of-register leucine zipper with a 3-residue insertion. The dynamic MITF is highly vulnerable to dimer-disrupting mutations, as we observed that MITF loss-of-function mutations in human Waardenburg syndrome type 2 A are frequently located on the dimer interface and disrupt the dimer forming ability accordingly. These observations suggest a unique opportunity to inhibit MITF with small molecules capable of disrupting the MITF dimer. From a high throughput screening against 654,650 compounds, we discovered compound TT-012, which specifically binds to dynamic MITF and destroys the latter's dimer formation and DNA-binding ability. Using chromatin immunoprecipitation assay and RNA sequencing, we showed that TT-012 inhibits the transcriptional activity of MITF in B16F10 melanoma cells. In addition, TT-012 inhibits the growth of high-MITF melanoma cells, and inhibits the tumor growth and metastasis with tolerable toxicity to liver and immune cells in animal models. Together, this study demonstrates a unique hyperdynamic dimer interface in melanoma oncoprotein MITF, and reveals a novel approach to therapeutically suppress MITF activity.
Access all drug discovery papers and probability of success in trials forecasts:
Access all drug discovery papers and probability of success in trials forecasts:
Drug Discovery Landscape
0 orphan drug designations.
0 orphan drug designations.
Let's accelerate rare disease drug discovery
Let's accelerate drug discovery
Get access to Explority AI’s forecasts to outperform average preclinical success rates. Whether you’re expanding your R&D pipeline, evaluating a partnership, or simply have a question — we’d love to hear from you.