Glial brain tumours, including astrocytoma IDH (Isocitrate Dehydrogenase) mutant and glioblastoma IDH wild-type, are highly malignant brain tumours with poor clinical outcomes. Genomic instability, encompassing microsatellite (MIN) and chromosomal instability (CIN), drives tumour heterogeneity and evolution. In this study, genomic instability was analysed in 85 patients using AP-PCR (Arbitrarily Primed Polymerase Chain Reaction) by comparing tumour and normal tissue (blood) DNA profiles of the same patient. Both types of alterations were present in all analysed samples, contributing almost equally to the total level of genomic instability. The dominant pattern of genomic instability in our cohort was low overall instability, predominantly manifesting as low-degree microsatellite instability. A general decrease in genomic instability was observed with increasing tumour grade. Glioblastoma IDH wild-type was more prevalent in older patients, whereas astrocytoma IDH mutant predominated in younger individuals. Notably, low genomic instability (both MIN and CIN) was associated with poorer survival in patients over 50 years of age. Females, compared to males, exhibited higher MIN in grade 2 tumours and elevated CIN in grade 4 tumours. Our results confirm that genomic instability contributes to tumour progression, MIN being the pivotal factor, and could serve as a prognostic biomarker in malignant gliomas.

Triple-negative breast cancer (TNBC) lacks effective targeted therapies, and the mechanisms by which developmental endothelial locus-1 (EDIL3/Del-1) promotes TNBC remain incompletely defined. We profiled Del-1 and AMPK subunits in TNBC cell lines by RT-PCR and immunoblotting, performed functional assays in CRISPR/Cas9 Del-1 knockout and AMPKβ-manipulated cells, and evaluated AMPKβ in early-stage TNBC tumors using tissue microarrays (TMA) (immunohistochemistry; n = 100) and AMPKβ2 mRNA quantification. Del-1 and AMPKβ were enriched in TNBC cells, most prominently in the mesenchymal stem-like subtype, whereas AMPKα levels were relatively stable. Increased Del-1 and activated AMPKβ enhanced proliferation and invasion, while Del-1 deletion reduced AMPKβ expression and suppressed tumor-promoting phenotypes. Mechanistically, Del-1 increased AMPKβ phosphorylation at serine 108, and a phospho-mimetic AMPKβ mutant further amplified oncogenic effects. In the pilot TMA study, high AMPKβ protein expression showed a trend toward poorer DFS in Kaplan-Meier analysis, while multivariate analysis identified high AMPKβ protein expression as an independent factor associated with poorer DFS in patients with early TNBC. These data support AMPKβ as a key mediator of Del-1-driven signaling and suggest AMPKβ could be a therapeutic target in aggressive TNBC subsets.

Pituitary neuroendocrine tumors (PitNETs) are usually benign intracranial neoplasms that may exhibit invasion of the cavernous sinus, complicating surgery and increasing the risk of recurrence. This study aimed to investigate membranous E-cadherin (mE-cad) expression across PitNET subtypes and transcription factor (TF) lineages, including Pit-1 (pituitary-specific positive transcription factor 1), SF-1 (Steroidogenic Factor 1), and TPIT (T-box pituitary transcription factor), and its association with tumor invasiveness in sixty-nine patients. mE-cad expression was evaluated as the percentage of positive cells (0%, 1-10%, >10%) and by immunoreactive score (IRS). Staining intensity was scored as: 0, no staining; 1, weak; 2, moderate; 3, strong. The proportion of positive cells was scored as: 0, none; 1, <10%; 2, 10-50%; 3, 51-80%; 4, >80%. Mean mE-cad expression was 5.2% in gonadotroph, 3.2% in corticotroph, 0.5% in lactotroph, and 17.5% in plurihormonal PitNETs. By TF lineage, the mean expression was 5.3% for Pit-1, 3.2% for TPIT, and 5.1% for SF-1. Low mE-cad expression (IRS 1-2) was associated with higher odds of cavernous sinus invasion compared with IRS 3-6 (adjusted OR = 6.0, 95% CI 1.08-33.4, p = 0.04), independent of tumor volume (adjusted OR = 4.0, 95% CI 1.50-10.7, p = 0.01). After restricting the analysis to the gonadotroph PitNET group, tumors with an IRS of 1-2 showed significantly higher invasiveness compared with those with an IRS of 3-6 (p = 0.012). These findings suggest that mE-cad may serve as a biomarker of PitNET invasiveness, with expression varying according to TF lineage and tumor subtype.

CRISPR screens are a powerful functional genomics approach for identifying genes that confer sensitivity and resistance to anti-cancer therapies. CFI-402257 (luvixasertib, 2257) is a small molecule inhibitor of threonine tyrosine kinase (TTK), a promising therapeutic target in genomically unstable cancers due to its critical role in establishing the spindle assembly checkpoint (SAC) during mitosis. To inform its ongoing development and evaluation in clinical trials, we sought to use CRISPR activation (i.e., gain of function) screens to identify cellular mechanisms of resistance to 2257 in models of triple-negative breast cancer (TNBC). In vitro screens conducted in two TNBC cell lines nominated ABCG2 as the top resistance-conferring gene in both models. Validation studies assessing clonogenic survival and apoptosis confirmed that ABCG2 overexpression enhanced TNBC resistance to 2257 in vitro, while knockdown enhanced sensitivity. These findings suggest that 2257 is a substrate of ABCG2's drug efflux activity. However, overexpression of ABCG2 failed to confer resistance to 2257 in TNBC xenografts grown in mice and treated with a moderately active dose and schedule. Our results highlight the potential impact of drug transporters in in vitro CRISPR screens and the importance of confirming the relevance of drug response mechanisms identified in cultured cells using in vivo models that recapitulate drug pharmacokinetics and pharmacodynamics.

Papillary thyroid cancer (PTC) is the most common endocrine malignancy with especially high incidence in Middle Eastern populations. While classical hereditary syndromes explain a minority of cases, the broader germline landscape of non-syndromic PTC remains unclear. Whole-exome sequencing was performed on 245 unselected Saudi PTC patients to identify germline pathogenic or likely pathogenic variants (PVs/LPVs) in cancer predisposition genes. Clinical and molecular characteristics, and family history were integrated to assess phenotypic correlations. Eleven patients (4.5%) harbored germline PVs/LPVs in cancer susceptibility genes including STK11, TP53, BRCA1, BRCA2, FANCA, SLX4, RAD50, MSH6, POLD1 and NF1. Four patients (36.4%) carried PVs/LPVs in canonical FA pathway genes; this increased to five patients (45.5%) when RAD50 was included. Two unrelated patients harbored the same STK11 variant (p.R304Q) without classical Peutz-Jeghers syndrome features. A TP53 hotspot mutation (p.R175H) was identified in a patient with a personal history of gastric cancer, a malignancy associated with Li-Fraumeni syndrome. Notably, the BRCA1 PV detected matches a known Saudi founder mutation in hereditary breast cancer, now observed in PTC. Most germline positive cases lacked syndromic manifestations, underscoring limitations of phenotype or family history-driven genetic testing strategies. These findings suggest that a small subset of non-syndromic PTC cases may carry germline PVs/LPVs in cancer predisposition genes, highlighting the need for broader genetic screening frameworks. Unbiased whole-exome analysis in unselected cohorts can uncover under-recognized genetic risk and guide screening strategies to address the unique hereditary landscape of thyroid cancer in underrepresented populations.

Leucine-rich repeat-containing 8A (LRRC8A; also known as SWELL1), the essential subunit of volume-regulated anion channels (VRACs), is amplified in multiple malignancies and has been implicated in tumor progression and therapeutic resistance. Three-dimensional (3D) cancer spheroids have been well-established as in vitro models that recapitulate characteristics of tumor stemness and intrinsic drug resistance. In the present study, spheroid formation in human breast cancer cell lines, YMB-1 and MDA-MB-468, conferred resistance to multiple anticancer drugs, including doxorubicin (DOX), gemcitabine (GEM), and 5-fluorouracil (5-FU), thereby mimicking the characteristic properties of breast cancer stem-like cells. LRRC8A expression was upregulated in 3D spheroids compared with adherent 2D monolayers, and its pharmacological inhibition induced membrane hyperpolarization accompanied by intracellular Cl- accumulation. Inhibition of LRRC8A significantly sensitized spheroids to DOX, GEM, and 5-FU. Spheroid formation increased the expression of multidrug resistance-related protein 3 (MRP3) and the drug-metabolizing enzyme cytochrome P450 3A4 (CYP3A4), whereas LRRC8A inhibition suppressed their expression. The transcriptional upregulation of MRP3 and CYP3A4 was mediated through the NRF2-CEBPB/D transcriptional axis. Collectively, these findings suggest that LRRC8A inhibition may represent a therapeutic strategy to overcome chemoresistance by repressing MRP3 and/or CYP3A4 expression in breast cancer stem cells.

Oligoprogressive disease (OPD) in non-small-cell lung cancer (NSCLC) is a clinical entity with peculiar behavior and treatment. OPD patients, during systemic therapy, may receive local ablative treatment (LAT) with survival benefit. The importance of OPD and the role of LAT has been comprehensively assessed in the setting of EGFR mutant and ALK-rearranged NSCLC during tyrosine kinase inhibitor (TKI) treatment, but it is still almost unexplored in the context of NSCLC harboring actionable oncogenic drivers other than EGFR and ALK. The aim of our review is to collect and discuss the available data about standard treatment in this latter setting, with special consideration given to the role of LAT in case of OPD in systemic treatment. Through a comprehensive PubMed and ClinicalTrials.gov search, we identified the available data and ongoing clinical trials addressing these aims. To date, only limited evidence supports the use of LAT in OPD involving NSCLC driven by these molecular alterations, mainly deriving from case reports and retrospective series. This highlights an unmet clinical need that warrants systematic and multicentric data collection to generate more robust evidence.

There is no approved drug therapy for schwannomas associated with NF2-related schwannomatosis (NF2-SWN). Neither life-saving surgical resection or radiation are curative and can compound the debilitating neurological effects of the schwannomas. We previously identified fimepinostat, a dual histone deacetylase (HDAC)/phosphoinositide-3 kinase (PI3K) inhibitor, as a promising drug candidate with pro-apoptotic effects on NF2-related schwannomas. This preclinical study used the pharmaceutical formulation of fimepinostat to confirm its efficacy in schwannomas and identify pro-apoptotic signaling pathways. Fimepinostat was tested in human schwannoma model cells, patient-derived primary vestibular and non-vestibular schwannoma cells, and in a sciatic nerve allograft model. The signaling pathways leading to caspase-3-dependent apoptosis were elucidated using immune assays, flow cytometry, imaging, proteome, and acetylome analysis. Acute exposure to fimepinostat led to p21-dependent cell cycle inhibition, upregulation of tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL R2), and downregulation of tumor necrosis factor receptor 1 (TNFR1), Yes-associated protein (YAP), and inhibitors of apoptosis. Moreover, fimepinostat downregulated cytokine and chemokine secretion increased by merlin loss in schwannoma cells. Fimepinostat is a promising new drug intervention for NF2-SWN patients with the potential to promote tumor regression.

In glioblastoma, the strong immunosuppression of the tumor immune microenvironment fosters tumor aggressiveness and decreases the effectiveness of therapeutic interventions, including immunotherapies. An intricate network of connections among tumor cells, stroma and infiltrating immune cells sustains immunosuppression. Lectins are immunoregulatory glycan-binding receptors contributing to immunosuppression. Their targeting is proposed as an appealing strategy for anti-cancer therapy. In this work, network-based approaches were exploited to identify a lectin profile that could dissect the complexity of tumor-immunity interactions in glioblastoma. Differential co-expression analysis, employing TCGA, CGGA and GTEx databases (145, 133 and 255 samples, respectively), identified a cluster of novel C-type lectins, with ASGR2 and CLEC12A as principal hubs. Furthermore, TIMER2.0 analysis revealed that their expression was significantly associated with immunosuppressive cells. ASGR2 and CLEC12A expression was also validated by cytofluorimetric analysis on both tumor and liquid biopsies from 20 glioblastoma patients. We report that ASGR2 and CLEC12A C-type lectins are associated with tumor-infiltrating immunosuppressive myeloid subsets and discriminate patients' poor prognosis. These results suggest that C-type lectins may contribute to the immunosuppressive network sustained by infiltrating myeloid immune cells in GB, resulting in exploitable targets for therapeutic interventions.

RNA editing is a critical post-transcriptional modification that contributes to transcriptomic and proteomic diversity. The most common A-to-I (recognized as G) RNA editing enzymes are adenosine deaminases acting on RNA 1 and 2 (ADAR1 and ADAR2, respectively), which mediate alterations across all regions of mRNA molecules. However, a systematic cross-tissue view of RNA editing and its molecular correlates is still lacking. Here, we developed a rapid method for ADAR editing assessment based on 24 frequently edited positions in coding regions, which enables faster estimation of RNA editing levels than previous methods. We applied this metric to assess RNA editing in normal and cancerous lung and colorectal tissues. We analyzed RNA and whole exome sequencing profiles of experimental 172 colorectal and 144 lung cancer samples, and literature 646 colorectal and 1037 lung cancer samples. We also examined two types of control tissues: tumor-matched normal tissues (51 colorectal and 108 lung samples) and healthy tissues (6 colorectal and 7 lung samples). Overall ADAR-mediated RNA editing levels were ~2.9- and ~4.7-fold higher in healthy controls than in colorectal and lung cancers, respectively. In addition to their well-known association with immune cells, we identified positive correlations of ADAR editing with 740 molecular pathways including those responsible for extracellular matrix organization, RAS-MAPK axis and G2/M phase cell cycle arrest, and negative-with 139 pathways responsible for DNA repair, apoptosis, expression of transposable elements, and other factors.

Chronic lymphocytic leukemia (CLL) is uncommon in Asia, and longitudinal genomic data from Asian cohorts are limited. We conducted serial whole-exome sequencing (WES) in a multicenter Korean cohort of newly diagnosed, elderly CLL treated with chlorambucil-obinutuzumab to evaluate mutational heterogeneity and clonal hematopoiesis of indeterminate potential (CHIP) during treatment and follow-up. Tumor-only variants were filtered, restricted to nonsynonymous or loss-of-function coding/splice-site mutations, and summarized as a binary patient-by-gene matrix for principal component analysis (PCA), trajectory analysis, and k-means clustering. CHIP was defined as ≥1 qualifying mutation in a prespecified CHIP gene set. Baseline PCA was more compact in patients with complete response at end of treatment, whereas partial response or progressive disease cases were more dispersed. PCA trajectories were compact and directionally consistent in complete responders, more dispersed in partial responders, and highly heterogeneous without a dominant direction in progressive disease. Clustering identified dispersed and compact clusters, and CHIP-associated mutations were enriched in the dispersed cluster (55.6% vs. 8.3%, Fisher's exact p = 0.0086). In paired samples collected 3-5 months after end of treatment, CHIP status changed in some patients. Serial WES may provide complementary information to treatment response, although these observations require confirmation in larger cohorts.

Deuterium abundance has been proposed as a modulator of cellular metabolism; however, its influence on cancer-associated gene expression networks remains incompletely characterized. We analyzed A549 lung adenocarcinoma cells cultured across four deuterium concentrations (40, 80, 150, and 300 ppm) using NanoString nCounter profiling. Expression data were processed through multistep filtering, symbolic trajectory encoding, and density-based spatial clustering (DBSCAN) to identify extreme expression responders, and Gaussian mixture modeling (GMM-6) to resolve coordinated gene-expression modules. DBSCAN identified 11 outlier genes under deuterium depletion, including reduced expression of multidrug-resistance-associated ABCB1 (-42% at 80 ppm), proliferative signaling component FGFR4 (-19%), and transcriptional amplifier MYCN (-24%). In contrast, enrichment at 300 ppm produced a broad increase in oncogenic expression (mean +44%), with marked elevation of inflammation-related (IL6, TGFBR2) and invasion-associated (MMP9) genes. GMM-6 clustering of the remaining core network resolved six functional modules, indicating that depletion preferentially reduces expression of genes associated with plasticity-related programs (Cluster 5: TGFB1, S100A4), while basal survival-associated genes (Cluster 6: BIRC5, RET) remain comparatively stable. Together, these results indicate that deuterium concentration acts as a bidirectional modulator of gene expression programs in the A549 model, with enrichment broadly elevating oncogenic expression and moderate depletion associated with selective downregulation of genes linked to resistance, signaling, and invasive behavior. Significance: Deuterium depletion is associated with reduced expression of genes involved in multidrug resistance, growth-factor signaling, and transcriptional amplification, revealing deuterium-responsive transcriptional vulnerabilities within the A549 lung adenocarcinoma model.

Following the establishment of the four molecular subtypes of breast cancer, additional biomarkers are required to further refine prognostication and patient stratification. Krüppel-like factors (KLFs), components of Wnt signaling, estrogen receptor beta (ERβ) isoforms, cyclin D1, and E-cadherin have been implicated in epithelial-mesenchymal transition, tumor proliferation, and disease progression. In this monocentric retrospective cohort study, tissue microarrays from 153 patients with histologically confirmed breast cancer were analyzed by immunohistochemistry to assess the expression of cytoplasmic Dkk1, β-catenin, and E-cadherin, as well as nuclear cyclin D1, KLF-4, KLF-5, and ERβ isoforms, using the Remmele and Stegner immunoreactive score. Associations between protein expression patterns with clinicopathological characteristics and survival outcomes using univariable and multivariable Cox regression analyses were examined. High cytoplasmic E-cadherin expression was associated with improved overall survival [hazard ratio (HR) 0.37, 95% confidence interval (95% CI) 0.18-0.77, p = 0.008], whereas high nuclear expression of KLF-4 (HR 2.63, 95% CI 1.32-5.22, p = 0.006) and KLF-5 (HR 2.16, 95% CI 1.01-4.65, p = 0.048) was associated with reduced overall survival. High ERβ1 expression showed a marginally protective association with the development of metastases (log-rank test p = 0.045). Importantly, nuclear KLF-4 expression remained independently associated with adverse overall survival after adjustment for tumor stage, lymph node status, molecular subtype, and other molecular markers (adjusted HR 4.09, 95% CI 1.93-8.67, p < 0.001). These findings identify nuclear KLF-4 as an adverse prognostic marker in breast cancer and support its potential relevance for molecular patient stratification.

Gliomas exhibit considerable molecular heterogeneity and immunological complexity, emphasizing the need for effective biomarkers and therapeutic targets. In this study, the Chinese Glioma Genome Atlas (CGGA-325/693) and The Cancer Genome Atlas (TCGA-LGG/GBM) cohorts were used to explore the pathological role of PHD finger protein 23 (PHF23) in gliomas. Machine learning algorithms were performed to construct a PHF23-related prognosis signature (PHF23-RPS). Our analysis revealed significant upregulation of PHF23 in high-grade gliomas, while the PHF23-RPS exhibited strong predictive performance (AUC = 0.853). Two molecular subtypes were identified; Cluster 2 was characterized as "inflamed yet immunosuppressive". This subtype displayed a tumor mutational burden (TMB) paradox, where elevated TMB failed to translate into survival benefits due to extensive M2 macrophage infiltration and checkpoint-mediated immune exhaustion. Pharmacogenomic screening and molecular dynamics simulations identified Entospletinib as a potential candidate targeting this immunosuppressive barrier, showing a stable binding affinity (-7.7 kcal/mol). Functional assays, including in vitro experiments and in vivo experiments via a male BALB/c nude mouse orthotopic glioma model (n = 6/group), confirmed that PHF23 silencing inhibited glioma malignancy. Our results identify PHF23 as a critical oncogenic driver in glioma and support the PHF23-RPS for risk stratification. Entospletinib may offer a potential immunomodulatory option for high-risk gliomas.

Colorectal cancer (CRC) is a prevalent malignant tumour, with its incidence and mortality rates consistently ranking among the highest and exhibiting an upward trend. Extensive screening and early diagnosis are crucial for managing CRC progression and improving patient prognosis. This study aims to construct a novel analytical framework for integrating the sequencing data from tumour tissue and peripheral blood. By integrating and analysing the multi-omics data and clinical data from tumour tissues and peripheral blood, we confirmed that the LTB4R gene is significantly upregulated not only in tumour tissues but also in the peripheral blood of CRC patients. Further single-cell RNA sequencing (scRNA-seq) and immune cell correlation analyses revealed that Leukotriene B4 receptor 1 (LTB4R) is primarily expressed in macrophages, T cells, and other immune cells, with a significant negative correlation observed with M1-type macrophages, suggesting its potential pro-tumourigenic role in CRC by suppressing M1 macrophage. Additionally, simulated gene knockout analysis (scTenifoldKnk) demonstrated that LTB4R knockout significantly impacts immune-related pathways, including immune response and immune receptor activity. These findings not only highlight the potential of LTB4R as a peripheral blood diagnostic marker for CRC but also elucidate its involvement in tumour progression, offering novel insights for early clinical diagnosis and tumour screening systems.

Chemotherapy has significantly improved survival in breast cancer and, in the neoadjuvant setting, contributes to tumor downstaging and increased rates of breast-conserving surgery while enabling in vivo assessment of tumor biology and chemosensitivity. Pathological complete response (pCR) is a key endpoint associated with favorable outcomes; however, tumor heterogeneity highlights the need for reliable predictive biomarkers. This study evaluated the mRNA expression of 13 candidate genes in relation to molecular subtypes and pathological response to neoadjuvant chemotherapy (NAC) to identify potential predictive and prognostic markers. Pretreatment core biopsies from 92 patients receiving NAC were analyzed by quantitative RT-PCR. Molecular subtypes were determined by immunohistochemistry (ER, PR, HER2, Ki67), and pathological response was classified using the Miller-Payne scale as good (MP 4/5) or poor (MP 1-3). Multivariate logistic regression assessed associations between gene expression, subtype, and pCR. Hormone receptor-positive tumors showed significantly higher expression of AXL, FGFR1, RAP80, GAS6, BTRCP, and ZNF217. Significant associations with pCR were observed for AXL, FGFR1, YAP, and BRCA1. Low AXL and BRCA1 expression levels were independently associated with pCR. In addition, their combined low expression was associated most strongly with breast pCR in this cohort. These findings should be interpreted as exploratory and require validation in independent cohorts.

Solid tumor research is undergoing a decisive transition: innovation is no longer simply "finding a new receptor" or "inhibiting a new enzyme", but integrating targets, biomarkers, and therapeutic modalities into strategies capable of anticipating tumor adaptation and therefore mechanisms of resistance [...].

Nuclear mechanics and mechanotransduction are involved in the migration and invasion process, such as those in which the cells need to deform themselves to pass through constrictions. Specifically, properties like nuclear softness, viscoelasticity, plasticity (like nuclear pore complexes) and deformability are critical in cancer and its malignant progression. The nucleus represents a physical barrier for the migration and invasion in dense 3D extracellular matrix (ECM) scaffolds. Therefore, the deformability of the nucleus seems to determine the migration limit in circumstances where the enzymatic remodeling of the surroundings is impaired. There are still significant knowledge gaps regarding effects of nuclear deformation during cancer dissemination. It seems that nuclear deformation can alter gene transcription, induce alternative splicing processes, impact nuclear envelope rupture, nuclear pore complex dilatation, damage the DNA, and increase the genomic instability. These mechanically induced alterations can in turn impact the migratory behavior of the cancer cells. The stiffness of the nucleus relies on the condensation of chromatin, and the nuclear lamina, which consists of a network of intermediate filaments underneath the nuclear envelope. All of this is discussed in the review and it is argued that nuclear deformability is universally found in various cancer types. Another focus is placed on the nuclear envelope proteins like emerin, and the SUN-KASH complex and how they contribute to the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, which consequently couples the nucleus and the cytoskeleton. It is argued that this connection is crucial for force transmission, which governs nuclear stiffness dynamically, depending on the force applied. In this review, recent findings are described that couple ECM-induced nuclear mechanosensing and mechanotransduction with the migration and invasion of cancer cells. Moreover, it is suspected that changes in the mechanosensory characteristics of the cell nucleus could play a pivotal part in the malignancy of cancer cells and the heterogeneity of tumors. Finally, it is discussed what impact the individual elements of the nucleus offer to mechanically alter cellular migration and invasion in cancer and its malignant progression.

PAX3 plays a vital role in regulating proper growth, migration, differentiation, and survival during development of normal tissues, including those derived from the embryonic neural crest. PAX3 is a transcription factor with two separate DNA-binding domains and can positively (and less frequently, negatively) regulate gene expression. The levels of PAX3 can be modified by upstream molecular pathways, and its subsequent downstream functions are regulated through a wide range of protein interactions and posttranscriptional modifications. PAX3 direct downstream target genes are other transcription regulators and factors that modulate cellular proliferation, lineage specificity, migration, and survival. The pathways that PAX3 regulates during development may be recycled and subverted during disease progression, for example, during cancer progression, growth, and metastasis. Indeed, PAX3 is overexpressed in several cancers, including melanoma, neuroblastoma, and rhabdomyosarcoma. While there is still much that is unknown about the mechanisms by which PAX3 controls such a wide array of key cellular functions, a great deal of progress has been made to advance our understanding of this critical and multi-faceted factor.

Xeroderma pigmentosum group B (XPB/ERCC3) and group D (XPD/ERCC2) helicases are integral components of the transcription factor IIH (TFIIH) complex, coordinating DNA unwinding during transcription initiation and nucleotide excision repair (NER). XPB functions as an ATP-driven translocase that generates torsional strain to promote promoter melting and DNA opening at lesion sites, whereas XPD acts as a 5' to 3' helicase responsible for lesion verification and extension of the repair bubble. Structural and biochemical studies have clarified how TFIIH subunits regulate these helicases-p52 and p8 modulate XPB's translocation activity, while p44, p62, and MAT1 control XPD's helicase function through conformational and compositional transitions within the complex. Beyond their canonical roles, XPB and XPD participate in diverse cellular pathways, including cell-cycle regulation and oxidative stress response, highlighting their involvement in maintaining genome integrity beyond repair and transcription. Mutations in either helicase lead to xeroderma pigmentosum (XP), trichothiodystrophy (TTD), or combined XP/Cockayne syndrome (XP/CS) phenotypes, emphasizing the essential role of TFIIH integrity for human health. Recent biochemical and pharmacological advances have further revealed the therapeutic relevance of these helicases-XPB as a target of small-molecule inhibitors such as triptolide, Minnelide, and spironolactone, and XPD as a potential modulator of cancer sensitivity to DNA-damaging treatments. Collectively, XPB and XPD exemplify the structural and functional versatility of TFIIH helicases across repair, transcription, and genome maintenance.