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Objectives: Early detection and accurate diagnosis of lymph node metastasis (LNM) in head and neck cancer (HNC) are crucial for enhancing patient prognosis and survival rates. Current imaging methods have limitations, necessitating new evaluation of new diagnostic techniques. This study investigates the potential of combining pre-operative CT and intra-operative fluorescence lifetime imaging (FLIm) to enhance LNM prediction in HNC using primary tumor signatures. Methods: CT and FLIm data were collected from 46 HNC patients. A total of 42 FLIm features and 924 CT radiomic features were extracted from the primary tumor site and fused. A support vector machine (SVM) model with a radial basis function kernel was trained to predict LNM. Hyperparameter tuning was conducted using 10-fold nested cross-validation. Prediction performance was evaluated using balanced accuracy (bACC) and the area under the ROC curve (AUC). Results: The model, leveraging combined CT and FLIm features, demonstrated improved testing accuracy (bACC: 0.71, AUC: 0.79) over the CT-only (bACC: 0.58, AUC: 0.67) and FLIm-only (bACC: 0.61, AUC: 0.72) models. Feature selection identified that a subset of 10 FLIm and 10 CT features provided optimal predictive capability. Feature contribution analysis identified high-pass and low-pass wavelet-filtered CT images as well as Laguerre coefficients from FLIm as key predictors. Conclusions: Combining CT and FLIm of the primary tumor improves the prediction of HNC LNM compared to either modality alone. Significance: This study underscores the potential of combining pre-operative radiomics with intra-operative FLIm for more accurate LNM prediction in HNC, offering promise to enhance patient outcomes.

Objectives: Early detection and accurate diagnosis of lymph node metastasis (LNM) in head and neck cancer (HNC) are crucial for enhancing patient prognosis and survival rates. Current imaging methods have limitations, necessitating new evaluation of new diagnostic techniques. This study investigates the potential of combining pre-operative CT and intra-operative fluorescence lifetime imaging (FLIm) to enhance LNM prediction in HNC using primary tumor signatures. Methods: CT and FLIm data were collected from 46 HNC patients. A total of 42 FLIm features and 924 CT radiomic features were extracted from the primary tumor site and fused. A support vector machine (SVM) model with a radial basis function kernel was trained to predict LNM. Hyperparameter tuning was conducted using 10-fold nested cross-validation. Prediction performance was evaluated using balanced accuracy (bACC) and the area under the ROC curve (AUC). Results: The model, leveraging combined CT and FLIm features, demonstrated improved testing accuracy (bACC: 0.71, AUC: 0.79) over the CT-only (bACC: 0.58, AUC: 0.67) and FLIm-only (bACC: 0.61, AUC: 0.72) models. Feature selection identified that a subset of 10 FLIm and 10 CT features provided optimal predictive capability. Feature contribution analysis identified high-pass and low-pass wavelet-filtered CT images as well as Laguerre coefficients from FLIm as key predictors. Conclusions: Combining CT and FLIm of the primary tumor improves the prediction of HNC LNM compared to either modality alone. Significance: This study underscores the potential of combining pre-operative radiomics with intra-operative FLIm for more accurate LNM prediction in HNC, offering promise to enhance patient outcomes. [ABSTRACT FROM AUTHOR]

Inactive state-selective KRAS(G12C) inhibitors.sup.1-8 demonstrate a 30-40% response rate and result in approximately 6-month median progression-free survival in patients with lung cancer.sup.9. The genetic basis for resistance to these first-in-class mutant GTPase inhibitors remains under investigation. Here we evaluated matched pre-treatment and post-treatment specimens from 43 patients treated with the KRAS(G12C) inhibitor sotorasib. Multiple treatment-emergent alterations were observed across 27 patients, including alterations in KRAS, NRAS, BRAF, EGFR, FGFR2, MYC and other genes. In preclinical patient-derived xenograft and cell line models, resistance to KRAS(G12C) inhibition was associated with low allele frequency hotspot mutations in KRAS(G12V or G13D), NRAS(Q61K or G13R), MRAS(Q71R) and/or BRAF(G596R), mirroring observations in patients. Single-cell sequencing in an isogenic lineage identified secondary RAS and/or BRAF mutations in the same cells as KRAS(G12C), where they bypassed inhibition without affecting target inactivation. Genetic or pharmacological targeting of ERK signalling intermediates enhanced the antiproliferative effect of G12C inhibitor treatment in models with acquired RAS or BRAF mutations. Our study thus suggests a heterogenous pattern of resistance with multiple subclonal events emerging during G12C inhibitor treatment. A subset of patients in our cohort acquired oncogenic KRAS, NRAS or BRAF mutations, and resistance in this setting may be delayed by co-targeting of ERK signalling intermediates. These findings merit broader evaluation in prospective clinical trials. Multiple treatment-emergent alterations appear in patients with advanced-stage cancer who were treated with a KRAS inhibitor., Author(s): Yulei Zhao [sup.1] , Yonina R. Murciano-Goroff [sup.2] , Jenny Y. Xue [sup.1] [sup.3] , Agnes Ang [sup.4] , Jessica Lucas [sup.1] , Trang T. Mai [sup.1] , Arnaud [...]

Introduction: Cervical spine defects result in spinal instability, putting the spinal cord and vertebral arteries at risk of damage and possibly devastating neurological injuries. The fibula free flap can span the spinal defects for stability. There is a paucity of literature on this technique. Method: Multi‐institutional retrospective case series reviewing patients who underwent cervical spine reconstruction with a fibula free flap. Patient demographic information, comorbidities, characteristics of cervical spine defects, and free flap complications were collected. Results: A total of 1187 fibula free flaps across 10 different institutions were reviewed. Thirteen patients (1.09%) underwent cervical spine reconstruction with a fibula free flap. Average age was 52.3 years old with an age range of 12–79 years. There were six males (46.1%) and seven females (53.8%). The most common defect etiology was infection (n = 6, 46.1%). Most commonly involved cervical spine level of the defect was C5 (n = 10) followed by C6 (n = 9) and C4 (n = 8). The majority of reconstructed defects spanned three or more cervical levels, (n = 9, 69.2%). Facial artery was the most common arterial anastomosis (n = 8). Eight patients (61.5%) required a tracheostomy during their postoperative course. None of the patients had symptomatic or radiographic nonunion. Conclusion: This case series demonstrates that a vascularized fibula flap is a potential reconstructive option for cervical spine defects, especially in defects greater than three cervical levels, in the setting of infection, and previously radiated patients. Level of Evidence: 4 Laryngoscope, 134:4923–4928, 2024 [ABSTRACT FROM AUTHOR]

Objectives To describe the impact that the coronavirus disease 2019 (COVID-19) pandemic had on the presentation of patients with head and neck cancer in a single tertiary care center. Study Design Retrospective cohort study. Setting Academic institution. Methods We performed a retrospective review of patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC) who presented as new patients between September 10, 2019, and September 11, 2020. Patients presenting during the 6 months leading up to the announcement of the pandemic (pre–COVID-19 period) on March 11, 2020, were compared to those presenting during the first 6 months of the pandemic (COVID-19 period). Demographics, time to diagnosis and treatment, and tumor characteristics were analyzed. Results There were a total of 137 patients analyzed with newly diagnosed malignancies. There were 22% fewer patients evaluated during the COVID-19 timeframe. The groups were similar in demographics, duration of symptoms, time to diagnosis, time to surgery, extent of surgery, and adjuvant therapy. There was a larger proportion of tumors classified as T3/T4 (61.7%) in the COVID-19 period vs the pre–COVID-19 period (40.3%) ( P = .024), as well as a larger median tumor size during the COVID-19 period ( P = .0002). There were no differences between nodal disease burden ( P = .48) and distant metastases ( P = .42). Conclusion Despite similar characteristics, time to diagnosis, and surgery, our findings suggest that there was an increase in primary tumor burden in patients with HNSCC during the early COVID-19 pandemic.

Background: For patients with oral cavity squamous cell carcinoma (OCSCC) without evidence of nodal metastasis (cN0) on pre-operative evaluation, there are no clear guidelines who should undergo elective neck dissection (END) versus clinical surveillance. Objective: To identify CT imaging characteristics of sub-centimeter lymph nodes that would help predict the likelihood of nodal metastases on pathology. Methods: Retrospective review of cN0 OCSCC patients at a tertiary academic medical center was performed. Inclusion criteria included elective neck dissection, pre-operative CT imaging and presence of metastatic disease within lymph nodes. Control group consisted of patients without nodal metastases on pathology. CT features that were evaluated included asymmetric size, disrupted fatty hilum, asymmetric number, presence of cortical nodule, cortical nodule size, and round/oval shape. We evaluated the associations between CT LN features and the presence of metastases using multi-level mixed-effects logistic regression models. Model evaluation was performed using 5-fold cross-validation. The positive predictive value (PPV) and negative predictive value (NPV) were calculated. Results: 26 patients in each study and control groups were included. Three-level mixed-effects logistic regression models indicated round/oval shape (OR = 1.39, p =.01), asymmetric number (OR = 7.20, p =.005), and disrupted fatty hilum (OR = 3.31, p =.04) to be independently predictive in a 3-variable model with sensitivity = 38.0%, specificity = 92.0%, and PPV = 93.8%. Conclusions: In cN0 OCSCC patients undergoing END, round/oval shape, asymmetric number, and disrupted fatty hilum of lymph nodes on pre-operative CT imaging are novel and highly predictive of occult nodal disease. [ABSTRACT FROM AUTHOR]

The incidence of oropharyngeal cancer (OPC) related to infection with human papillomavirus (HPV) is rising, making it now the most common HPV-related malignancy in the United States. These tumors present differently than traditional mucosal head and neck cancers, and those affected often lack classic risk factors such as tobacco and alcohol use. Currently, there are no approved approaches for prevention and early detection of disease, thus leading many patients to present with advanced cancers requiring intense surgical or nonsurgical therapies resulting in significant side effects and cost to the health-care system. In this review, we outline the evolving epidemiology of HPV-related OPC. We also summarize the available evidence corresponding to HPV-related OPC prevention, including efficacy and safety of the HPV vaccine in preventing oral HPV infections. Finally, we describe emerging techniques for identifying and screening those who may be at high risk for developing these tumors.

Antisense oligonucleotides (ASOs) targeting pathologic RNAs have shown promising therapeutic corrections for many genetic diseases including myotonic dystrophy (DM1). Thus, ASO strategies for DM1 can abolish the toxic RNA gain-of-function mechanism caused by nucleus-retained mutant DMPK (DM1 protein kinase) transcripts containing CUG expansions (CUGexps). However, systemic use of ASOs for this muscular disease remains challenging due to poor drug distribution to skeletal muscle. To overcome this limitation, we test an arginine-rich Pip6a cell-penetrating peptide and show that Pip6aconjugated morpholino phosphorodiamidate oligomer (PMO) dramatically enhanced ASO delivery into striated muscles of DM1 mice following systemic administration in comparison with unconjugated PMO and other ASO strategies. Thus, low-dose treatment with Pip6a-PMO-CAG targeting pathologic expansions is sufficient to reverse both splicing defects and myotonia in DM1 mice and normalizes the overall disease transcriptome. Moreover, treated DM1 patient-derived muscle cells showed that Pip6a-PMO-CAG specifically targets mutant CUGexp-DMPK transcripts to abrogate the detrimental sequestration of MBNL1 splicing factor by nuclear RNA foci and consequently MBNL1 functional loss, responsible for splicing defects and muscle dysfunction. Our results demonstrate that Pip6a-PMO-CAG induces long- lasting correction with high efficacy of DM1-associated phenotypes at both molecular and functional levels, and strongly support the use of advanced peptide conjugates for systemic corrective therapy in DM1., Introduction Myotonic dystrophy (DM1), one of the most common muscular dystrophies in adults (1), is an RNA-dominant disorder caused by the expression of expanded microsatellite repeats located in the 3' [...]

Background: Novel, non-invasive diagnostic biomarkers that facilitate early intervention in head and neck cancer are urgently needed. Polyamine metabolites have been observed to be elevated in numerous cancer types and correlated with poor prognosis. The aim of this study was to assess the concentration of polyamines in the saliva and urine from head and neck cancer (HNC) patients, compared to healthy controls. Methods: Targeted metabolomic analysis was performed on saliva and urine from 39 HNC patient samples and compared to 89 healthy controls using a quantitative, targeted liquid chromatography mass spectrometry approach. Results: The metabolites N1-acetylspermine (ASP), N8-acetylspermidine (ASD) and N1,N12-diacetylspermine (DAS) were detected at significantly different concentrations in the urine of HNC patients as compared to healthy controls. Only ASP was detected at elevated levels in HNC saliva as compared to healthy controls. Conclusion: These data suggest that assessment of polyamine-based metabolite biomarkers within the saliva and urine warrants further investigation as a potential diagnostic in HNC patients.

Myotonic dystrophy type 1 (DM1) and type 2 (DM2) are autosomal dominant neuromuscular diseases caused by microsatellite expansions and belong to the family of RNA-dominant disorders. Availability of cellular models in which the DM mutation is expressed within its natural context is essential to facilitate efforts to identify new therapeutic compounds. Here, we generated immortalized DM1 and DM2 human muscle cell lines that display nuclear RNA aggregates of expanded repeats, a hallmark of myotonic dystrophy. Selected clones of DM1 and DM2 immortalized myoblasts behave as parental primary myoblasts with a reduced fusion capacity of immortalized DM1 myoblasts when compared with control and DM2 cells. Alternative splicing defects were observed in differentiated DM1 muscle cell lines, but not in DM2 lines. Splicing alterations did not result from differentiation delay because similar changes were found in immortalized DM1 transdifferentiated fibroblasts in which myogenic differentiation has been forced by overexpression of MYOD1. As a proof-of-concept, we show that antisense approaches alleviate disease-associated defects, and an RNA-seq analysis confirmed that the vast majority of mis-spliced events in immortalized DM1 muscle cells were affected by antisense treatment, with half of them significantly rescued in treated DM1 cells. Immortalized DM1 muscle cell lines displaying characteristic disease-associated molecular features such as nuclear RNA aggregates and splicing defects can be used as robust readouts for the screening of therapeutic compounds. Therefore, immortalized DM1 and DM2 muscle cell lines represent new models and tools to investigate molecular pathophysiological mechanisms and evaluate the in vitro effects of compounds on RNA toxicity associated with myotonic dystrophy mutations.

Sediment transport is a key process that affects the morphology and ecological habitat diversity of rivers. As part of a gravel augmentation program to mitigate sediment deficit below a dam, gravel mobility in the Ain River in Eastern France was investigated by tracking of a large amount (n = 1,063) of PIT‐tagged gravels in the field, conducting a probabilistic approach based on published tracer studies, and performing two‐dimensional (2D) numerical modeling of flow and bedload transport. This comparative study highlights the strengths, weaknesses, and complementary aspects of the three approaches to the understanding of river gravel mobility. Thanks to recent technological improvements, PIT‐tagged gravels provide an increasingly reliable and accurate representation of bedload movement in the field, although it remains limited in spatio‐temporal resolution. Based on an exponential distribution, the probabilistic approach correctly reproduces the average trend in travel distances by the different classes of particles over hydrological periods, including one or several significant floods. Furthermore, the 2D numerical modeling accounts for the variability of local hydrodynamic conditions and can simulate realistic displacement distributions for the different classes of particles with high spatio‐temporal resolution. Numerical modeling is a very encouraging approach, which makes our study original because it is the first time that the estimation of mean travel distances, the application of an exponential distribution, and the comparison with a hydrodynamic model are combined. A more effective modeling strategy involves incorporating a probabilistic transport model in the 2D numerical model to reproduce the observed scatter of the individual particle trajectories. Key Points: PIT‐tagged gravels are used to track gravel mobility in the restored Ain RiverThe results of field tracer surveys are compared with probabilistic and two‐dimensional numerical modelingThe three approaches are found to be meaningful and complementary [ABSTRACT FROM AUTHOR]

Myotonic dystrophy type 1 (DM1 also known as Steinert disease) is a multisystemic disorder mainly characterized by myotonia, progressive muscle weakness and wasting, cognitive impairments, and cardiac defects. This autosomal dominant disease is caused by the expression of nuclear retained RNAs containing pathologic expanded CUG repeats that alter the function of RNA-binding proteins in a tissue-specific manner, leading ultimately to neuromuscular dysfunction and clinical symptoms. Although considerable knowledge has been gathered on myotonic dystrophy since its first description, the development of novel relevant disease models remains of high importance to investigate pathophysiologic mechanisms and to assess new therapeutic approaches. In addition to animal models, in vitro cell cultures provide a unique resource for both fundamental and translational research. This review discusses how cellular models broke ground to decipher molecular basis of DM1 and describes currently available cell models, ranging from exogenous expression of the CTG tracts to variable patients’ derived cells.

Objective: To identify patient factors in older patients associated with making posttreatment visits in the first year after major head and neck oncologic surgery. Study Design: Retrospective cohort study. Setting: Academic institution. Methods: Patients aged ≥60 years who underwent a neck dissection with or without a free flap reconstruction were retrospectively analyzed. Data collected included patient demographics, comorbidities, social variables, perioperative course, and clinical visits. Results: Within a 1‐year postoperative period, the 181 patients in our cohort had a mean ± SD 6.37 ± 3.6 postoperative clinic visits; 70% attended at least 4 visits. Multivariable regression analysis showed a significant association with distance closer to the hospital (P =.013): for every 10‐mile increase in distance, the number of visits decreased by 0.15 (SE = 0.06). Additionally, receiving adjuvant radiation therapy (P =.0096) demonstrated significant associations: when compared with no adjuvant therapy, radiation therapy had on average 1.5 (SE = 0.56) more visits, and chemoradiation had 0.04 (SE = 0.73) more visits. Conclusion: Older patients who undergo major head and neck oncology surgery are more likely to attend posttreatment visits in the 1 year following surgery if they are discharged home rather than to a skilled nursing facility, live closer to the hospital, and undergo adjuvant radiation therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Due to the overall favorable prognosis for p16+ oropharyngeal squamous cell carcinoma (OPSCC), de-escalation protocols are being implemented at a higher rate. However, there remains uncertainty regarding the best candidates for de-escalation therapy. Currently, tumor stage, p16 status, and history of smoking are widely accepted as influencing prognosis in OPSCC. Tumor and lymph node growth rates could potentially add to this growing list of prognosticators. Thus far, there is scant literature that defines tumor and nodal growth rate in OPSCC. In this study, we utilize radiation oncology software and interval CT scans to both define these rates and analyze their prognostic value. This analysis may offer a more comprehensive understanding of the natural course of OPSCC growth and aid head and neck surgeons, medical oncologists, and radiation oncologists in risk stratification. Though specific growth rate (SGR) has potential prognostic value for oropharyngeal squamous cell carcinoma (OPSCC), there is sparse literature defining these rates. Our aims were to establish the SGRs of primary tumors (PTs) and lymph nodes (LNs) in OPSCC and to correlate SGR with oncologic outcome. A pilot study was designed with a retrospective analysis examining 54 patients from the University of California, Davis with OPSCC (diagnosed 2012–2019). Radiation oncology software and pretreatment serial CT scans were used to measure PT and LN volumes to calculate SGR and doubling time (DT). The mean PT-SGR was 1.2 ± 2.2%/day and the mean LN-SGR was 1.6 ± 1.9%/day. There was no statistically significant difference between slow-growing and fast-growing cohorts in terms of age, gender, smoking status, tumor subsite, HPV status (as determined with p16 staining), initial volume, or overall stage. SGR had no impact on 2-year overall survival, disease-free survival, or disease-specific survival. We found the average daily growth rates for OPSCC to be 1.2%/day and 1.6%/day. Our findings suggest PT- and LN-SGR are independent factors, not heavily influenced by known biomarkers and patient characteristics, without a statistical impact on prognosis. This information has value in patient counseling regarding tumor growth and in providing patients worried about fast-growing tumors the appropriate reassurance. [ABSTRACT FROM AUTHOR]

Drug-induced liver injury (DILI) is a major clinical problem where natural compounds hold promise for its abrogation. Khaya grandifoliola (Meliaceae) is used in Cameroonian traditional medicine for the treatment of liver related diseases and has been studied for its hepatoprotective properties. Till date, reports showing the hepatoprotective molecular mechanism of the plant are lacking. The aim of this study was therefore to identify compounds from the plant bearing hepatoprotective activity and the related molecular mechanism by assessing their effects against acetaminophen (APAP)-induced hepatotoxicity in normal human liver L-02 cells line. The cells were exposed to APAP (10 mM) or co-treated with phytochemical compounds (40 μM) over a period of 36 h and, biochemical and molecular parameters assessed. Three known limonoids namely 17-epi-methyl-6-hydroxylangolensate, 7-deacetoxy-7-oxogedunin and deacetoxy-7R-hydroxygedunin were identified. The results of cells viability and membrane integrity, reactive oxygen species generation and lipid membrane peroxidation assays, cellular glutathione content determination as well as expression of cytochrome P450 2E1 demonstrated the protective action of the limonoids. Immunoblotting analysis revealed that limonoids inhibited APAP-induced c-Jun N-terminal Kinase phosphorylation (p-JNK), mitochondrial translocation of p-JNK and Bcl2-associated X Protein, and the release of Apoptosis-inducing Factor into the cytosol. Interestingly, limonoids increased the expression of Mitogen-activated Protein Kinase Phosphatase (Mkp)-1, an endogenous inhibitor of JNK phosphorylation and, induced the nuclear translocation of Nuclear Factor Erythroid 2-related Factor-2 (Nrf2) and decreased the expression of Kelch-like ECH-associated Protein-1. The limonoids also reversed the APAP-induced decreased mRNA levels of Catalase, Superoxide Dismutase-1, Glutathione-S-Transferase and Methionine Adenosyltransferase-1A. The obtained results suggest that the isolated limonoids protect L-02 hepatocytes against APAP-induced hepatotoxicity mainly through increase expression of Mkp-1 and nuclear translocation of Nrf2. Thus, these compounds are in part responsible of the hepatoprotective activity of K. grandifoliola and further analysis including in vivo and toxicological studies are needed to select the most potent compound that may be useful as therapeutic agents against DILI.

There are limited data supporting the commonly suggested 5 mm margin cutoff as the optimum value in defining clear margins in oral cancer. A database search of Pubmed/Medline, Web of Science, and EBSCOhost was performed from inception to June 2022. A random‐effects model was chosen for this meta‐analysis. The Preferred Reporting Items for Systematic Reviews and Meta‐analyses (PRISMA) guidelines were followed throughout this study. Seven studies met study criteria (2215 patients). The risk ratio was significantly higher for margins <5 mm when compared to those ≥5 mm (2.09 (95%CI: 1.53–2.86, I2 = 0.47)). Subgroup analysis (I2 = 0.15) of margin distances of 0.0–0.9, 1.0–1.9, 2.0–2.9, 3.0–3.9, and 4.0–4.9 mm calculated risk ratios for local recurrence of 2.96, 2.01, 2.17, 1.8, and 0.98, respectively. Margins between 4.0 and 4.9 mm had similar risk ratios for local recurrence compared to ≥5 mm, while margins <4.0 were significantly higher. [ABSTRACT FROM AUTHOR]

Abstract Background and Importance Chondroblastoma is a benign primary bone tumor that typically develops in the epiphyses of long bones. Chondroblastoma of the craniofacial skeleton is extremely rare, with most cases occurring in the squamosal portion of the temporal bone. In this report, we describe the first case of chondroblastoma of the clivus presenting with cranial neuropathy that was treated with endoscopic endonasal resection. We review the literature on craniofacial chondroblastomas with particular emphasis on extratemporal lesions. Case Presentation A 27-year-old woman presented with severe headache, left facial dysesthesias, and diplopia. Physical examination revealed hypesthesia in the left maxillary nerve dermatome, and complete left abducens nerve palsy. Imaging demonstrated an expansile intraosseous mass originating in the upper clivus with extension superiorly into the sella turcica and laterally to involve the medial wall of the left cavernous sinus. The tumor was completely resected via an endoscopic endonasal approach, with postoperative improvement in lateral gaze palsy. Histopathology was consistent with chondroblastoma. Conclusion Chondroblastoma is a rare tumor of the craniofacial skeleton that should be included in the differential diagnosis of an osteolytic lesion of the clivus. Complete surgical resection remains the mainstay of treatment.

Oculopharyngeal muscular dystrophy (OPMD) is caused by expansion of a (GCN)10 to a (GCN)11–17 repeat coding for a polyalanine domain at the N-terminal part of poly(A) binding protein nuclear 1 (PABPN1). OPMD is characterized by the presence of intranuclear inclusions (INIs) in skeletal muscle fibers of patients. The formation of GFP-b13AlaPABPN1 INIs and their fate through the cell cycle were followed by time-lapse imaging. Our observations demonstrated that the GFP-b13AlaPABPN1 INIs are dynamic structures that can disassemble during mitosis. However, their presence in cells occasionally led to apoptosis. The length of the polyalanine tail or the overexpression of PABPN1 did not significantly affect the percentage of soluble PABPN1 in vitro. Moreover, overexpression of either the wild type (wt) or mutant (mut) forms of PABPN1 slowed down the cell proliferation. The slowing down of proliferation together with the occasional occurrence of apoptosis could contribute in vivo to the late onset of this disease.

Oculopharyngeal muscular dystrophy (OPMD) is an adult-onset disease caused by expanded (GCN)12–17 stretches encoding the N-terminal polyalanine domain of the poly(A) binding protein nuclear 1 (PABPN1). OPMD is characterized by intranuclear inclusions (INIs) in skeletal muscle fibers, which contain PABPN1, molecular chaperones, ubiquitin, proteasome subunits, and poly(A)-mRNA. We describe an adenoviral model of PABPN1 expression that produces INIs in most cells. Microarray analysis revealed that PABPN1 overexpression reproducibly changed the expression of 202 genes. Sixty percent of upregulated genes encode nuclear proteins, including many RNA and DNA binding proteins. Immunofluorescence microscopy revealed that all tested nuclear proteins encoded by eight upregulated genes colocalize with PABPN1 within the INIs: CUGBP1, SFRS3, FKBP1A, HMG2, HNRPA1, PRC1, S100P, and HSP70. In addition, CUGBP1, SFRS3, and FKBP1A were also found in OPMD muscle INIs. This study demonstrates that a large number of nuclear proteins are sequestered in OPMD INIs, which may compromise cellular function.