Feasibility of Multimodal Artificial Intelligence Using GPT-4 Vision for the Classification of Middle Ear Disease: Qualitative Study and Validation.

BACKGROUND: The integration of artificial intelligence (AI), particularly deep learning models, has transformed the landscape of medical technology, especially in the field of diagnosis using imaging and physiological data. In otolaryngology, AI has shown promise in image classification for middle ear diseases. However, existing models often lack patient-specific data and clinical context, limiting their universal applicability. The emergence of GPT-4 Vision (GPT-4V) has enabled a multimodal diagnostic approach, integrating language processing with image analysis. OBJECTIVE: In this study, we investigated the effectiveness of GPT-4V in diagnosing middle ear diseases by integrating patient-specific data with otoscopic images of the tympanic membrane. METHODS: The design of this study was divided into two phases: (1) establishing a model with appropriate prompts and (2) validating the ability of the optimal prompt model to classify images. In total, 305 otoscopic images of 4 middle ear diseases (acute otitis media, middle ear cholesteatoma, chronic otitis media, and otitis media with effusion) were obtained from patients who visited Shinshu University or Jichi Medical University between April 2010 and December 2023. The optimized GPT-4V settings were established using prompts and patients' data, and the model created with the optimal prompt was used to verify the diagnostic accuracy of GPT-4V on 190 images. To compare the diagnostic accuracy of GPT-4V with that of physicians, 30 clinicians completed a web-based questionnaire consisting of 190 images. RESULTS: The multimodal AI approach achieved an accuracy of 82.1%, which is superior to that of certified pediatricians at 70.6%, but trailing behind that of otolaryngologists at more than 95%. The model's disease-specific accuracy rates were 89.2% for acute otitis media, 76.5% for chronic otitis media, 79.3% for middle ear cholesteatoma, and 85.7% for otitis media with effusion, which highlights the need for disease-specific optimization. Comparisons with physicians revealed promising results, suggesting the potential of GPT-4V to augment clinical decision-making. CONCLUSIONS: Despite its advantages, challenges such as data privacy and ethical considerations must be addressed. Overall, this study underscores the potential of multimodal AI for enhancing diagnostic accuracy and improving patient care in otolaryngology. Further research is warranted to optimize and validate this approach in diverse clinical settings.

Role of Facial Nerve Reconstruction With Anastomosis and Polyglycolic Acid Tube in Accelerating Functional Recovery After Axotomy in the Rat Facial Nucleus.

Facial nerve injuries stem from trauma or tumor surgery, triggering neurodegeneration and neuronal cell death in the facial nucleus, consequently inducing irreversible nerve paralysis. Following facial nerve transection, glial cells are activated and undergo proliferation, facilitating motor neuron survival, repair, and regeneration. Clinical approaches, including nerve anastomosis and hypoglossal nerve grafting, require delicate microscopic techniques. Recent advancements involve nerve reconstruction using polyglycolic acid (PGA) tubes, which yield nerve function improvement. However, the central pathophysiological effects of these procedures remain unclear. Therefore, using PGA tubes, we evaluated neurodegeneration and microglial inflammatory response in rats after facial nerve transection. Facial nerve functions were evaluated using vibrissae and blink reflex scores. In the end-to-end anastomosis and PGA tube reconstruction groups, a partial improvement in facial motor function was observed, with increased nerve fiber survival in the former. Approximately 90% of neurons survived in both groups, wherein gliosis exhibited increased microglial activation compared to that in the transection group. These results indicate that PGA tube-assisted nerve reconstruction post-facial nerve transection, although inferior to end-to-end anastomosis, improved certain functions and prevented neuronal cell death. Furthermore, the prolonged inflammatory response in the facial nerve nucleus underscored the correlation between neuronal function and survival and microglia.

Intact Transmastoid Ossicle Swaying Technique to Preserve Hearing in Pediatric Facial Nerve Decompression Surgery: A Case Report.

When pharmacological treatments are inadequate, facial nerve paralysis from various etiologies, including Bell's palsy, Hunt syndrome, and trauma, often requires surgical intervention. Facial nerve decompression surgery aims to relieve nerve compression and restore function, with preserving hearing function, especially in pediatric cases, being crucial. Conventional methods, like the transmastoid approach, risk affecting auditory function due to ossicle manipulation. Herein, we describe the case of a 12-year-old boy with left facial palsy diagnosed with zoster sine herpete (ZSH) syndrome. Despite medical treatment, the patient's condition did not improve, prompting facial nerve decompression surgery. Employing the intact transmastoid ossicle (ITO) swaying technique, we minimized ossicular manipulation, preserving auditory function while effectively achieving facial nerve decompression. The patient demonstrated improvement postoperatively in auditory and facial nerve functions. Furthermore, audiometric assessments demonstrated no substantial deterioration in hearing thresholds, and the facial nerve function improved from Grade V to Grade II on the House-Brackmann scale. The ITO technique provides a less invasive alternative compared to conventional approaches, lowering the chance of the ossicular chain and the risk of postoperative hearing loss. This case highlights the significance of customized surgical approaches in pediatric facial nerve decompression surgery, resulting in improved patient outcomes. Further research is required to validate the efficacy and safety of this method across various clinical contexts.

Performance of GPT-4V in Answering the Japanese Otolaryngology Board Certification Examination Questions: Evaluation Study.

BACKGROUND: Artificial intelligence models can learn from medical literature and clinical cases and generate answers that rival human experts. However, challenges remain in the analysis of complex data containing images and diagrams. OBJECTIVE: This study aims to assess the answering capabilities and accuracy of ChatGPT-4 Vision (GPT-4V) for a set of 100 questions, including image-based questions, from the 2023 otolaryngology board certification examination. METHODS: Answers to 100 questions from the 2023 otolaryngology board certification examination, including image-based questions, were generated using GPT-4V. The accuracy rate was evaluated using different prompts, and the presence of images, clinical area of the questions, and variations in the answer content were examined. RESULTS: The accuracy rate for text-only input was, on average, 24.7% but improved to 47.3% with the addition of English translation and prompts (P<.001). The average nonresponse rate for text-only input was 46.3%; this decreased to 2.7% with the addition of English translation and prompts (P<.001). The accuracy rate was lower for image-based questions than for text-only questions across all types of input, with a relatively high nonresponse rate. General questions and questions from the fields of head and neck allergies and nasal allergies had relatively high accuracy rates, which increased with the addition of translation and prompts. In terms of content, questions related to anatomy had the highest accuracy rate. For all content types, the addition of translation and prompts increased the accuracy rate. As for the performance based on image-based questions, the average of correct answer rate with text-only input was 30.4%, and that with text-plus-image input was 41.3% (P=.02). CONCLUSIONS: Examination of artificial intelligence's answering capabilities for the otolaryngology board certification examination improves our understanding of its potential and limitations in this field. Although the improvement was noted with the addition of translation and prompts, the accuracy rate for image-based questions was lower than that for text-based questions, suggesting room for improvement in GPT-4V at this stage. Furthermore, text-plus-image input answers a higher rate in image-based questions. Our findings imply the usefulness and potential of GPT-4V in medicine; however, future consideration of safe use methods is needed.

Performance of Generative Pretrained Transformer on the National Medical Licensing Examination in Japan.

The remarkable performance of ChatGPT, launched in November 2022, has significantly impacted the field of natural language processing, inspiring the application of large language models as supportive tools in clinical practice and research worldwide. Although GPT-3.5 recently scored high on the United States Medical Licensing Examination, its performance on medical licensing examinations of other nations, especially non-English speaking nations, has not been sufficiently evaluated. This study assessed GPT's performance on the National Medical Licensing Examination (NMLE) in Japan and compared it with the actual minimal passing rate for this exam. In particular, the performances of both the GPT-3.5 and GPT-4 models were considered for the comparative analysis. We initially used the GPT models and several prompts for 290 questions without image data from the 116th NMLE (held in February 2022 in Japan) to maximize the performance for delivering correct answers and explanations of the questions. Thereafter, we tested the performance of the best GPT model (GPT-4) with optimized prompts on a dataset of 262 questions without images from the latest 117th NMLE (held in February 2023). The best model with the optimized prompts scored 82.7% for the essential questions and 77.2% for the basic and clinical questions, both of which sufficed the minimum passing scoring rates of 80.0% and 74.6%, respectively. After an exploratory analysis of 56 incorrect answers from the model, we identified the three major factors contributing to the generation of the incorrect answers-insufficient medical knowledge, information on Japan-specific medical system and guidelines, and mathematical errors. In conclusion, GPT-4 with our optimized prompts achieved a minimum passing scoring rate in the latest 117th NMLE in Japan. Beyond its original design of answering examination questions for humans, these artificial intelligence (AI) models can serve as one of the best "sidekicks" for solving problems and addressing the unmet needs in the medical and healthcare fields.

Macrophage depletion attenuates degeneration of spiral ganglion neurons in kanamycin-induced unilateral hearing loss model.

Pathological conditions in cochlea, such as ototoxicity, acoustic trauma, and age-related cochlear degeneration, induce cell death in the organ of Corti and degeneration of the spiral ganglion neurons (SGNs). Although macrophages play an essential role after cochlear injury, its role in the SGNs is limitedly understood. We analyzed the status of macrophage activation and neuronal damage in the spiral ganglion after kanamycin-induced unilateral hearing loss in mice. The number of ionized calcium-binding adapter molecule 1 (Iba1)-positive macrophages increased 3 days after unilateral kanamycin injection. Macrophages showed larger cell bodies, suggesting activation status. Interestingly, the number of activating transcription factor 3 (ATF3)-positive-neurons, an indicator of early neuronal damage, also increased at the same timing. In the later stages, the number of macrophages decreased, and the cell bodies became smaller, although the number of neuronal deaths increased. To understand their role in neuronal damage, macrophages were depleted via intraperitoneal injection of clodronate liposome 24 h after kanamycin injection. Macrophage depletion decreased the number of ATF3-positive neurons at day 3 and neuronal death at day 28 in the spiral ganglion following kanamycin injection. Our results suggest that suppression of inflammation by clodronate at early timing can protect spiral ganglion damage following cochlear insult.

Smartphone-Assisted Medical Care for Vestibular Dysfunction as a Telehealth Strategy for Digital Therapy Beyond COVID-19: Scoping Review.

BACKGROUND: Dizziness and vertigo can be caused by various factors, such as peripheral vestibular and central disorders. Although consultations with specialists are advisable when necessary, patients with severe vertigo symptoms may have limited mobility, which may interfere with hospital visits. The spread of COVID-19 has further limited the number of hospital visits for patients with dizziness; therefore, a method of medical care that enables more accurate treatment under time and geographical constraints is needed. Telemedicine has become widespread, owing to the popularity of smartphone and tablet devices in recent years, and the use of devices and systems has made it possible to provide efficient medical care. However, no previous scoping review has mapped existing studies on telemedicine for vertigo and dizziness, and no recommendations have been made regarding which devices and systems should be used for specific diseases. OBJECTIVE: The aim of this review was to map and assess previous studies on the use of information communications technology, smartphones, and apps for treating patients with vertigo and discuss the added value of introducing telemedicine to improve the quality of medical care and create an environment that builds security and trust among patients. METHODS: A scoping review was conducted with the methodological framework of Arksey and O'Malley and in accordance with the of the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews) guidelines. The PubMed, MEDLINE, and Cochrane Library databases were searched to retrieve previous reports on smartphone-assisted telemedicine treatment for vertigo published between January 2000 and May 2023. Two authors independently assessed eligibility and extracted data. RESULTS: This review included 20 papers that reported devices or systems for telemedicine for vestibular dysfunction. Among studies that reported the use of a device or app, 2 were related to anamnesis and subjective symptoms, 12 were related to objective examination, 7 were related to remote diagnosis, and 7 were related to treatment and rehabilitation. CONCLUSIONS: With the advancement of technology, the use of telemedicine in patients with dizziness may be feasible. In the future, it will be necessary to consider how telemedicine can be used in dizziness treatment and develop an effective treatment system combining in-person medical care and the effective use of devices for the management of severe vertigo and related diseases. The smooth introduction of telemedicine in vertigo treatment is expected to improve the quality of treatment, increase opportunities for patients to receive medical care, and reduce time and travel costs, leading to a sense of security and trust among patients.

Enhanced Cochlear Transduction by AAV9 with High-Concentration Sucrose.

The inner ear is a primary lesion in sensorineural hearing loss and has been a target in gene therapy. The efficacy of gene therapy depends on achieving sufficient levels of transduction at a safe vector dose. Vectors derived from various adeno-associated viruses (AAVs) are predominantly used to deliver therapeutic genes to inner ear cells. AAV9 and its variants vector are attractive candidates for clinical applications since they can cross the mesothelial cell layer and transduce inner hair cells (IHCs), although this requires relatively high doses. In this study, we investigated the effects of sucrose on the transduction of a variant of the AAV9 vector for gene transfer in the inner ear. We found that high concentrations of sucrose increased gene transduction in House Ear Institute-Organ of Corti 1 (HEI-OC1) cells in vitro. In addition, we demonstrated that simultaneous administration of sucrose enhanced the transduction of mouse IHCs and spiral ligament cells using an AAV9 variant vector. The procedure did not increase the thresholds in the auditory brainstem response, suggesting that sucrose had no adverse effect on auditory function. This versatile method may be valuable in the development of novel gene therapies for adult-onset sensorineural hearing loss.

Efficacy of endoscopic powered intracapsular tonsillectomy and adenoidectomy for pediatric obstructive sleep apnea: A retrospective case-control study.

OBJECTIVE: Safe surgery for pediatric patients with obstructive sleep apnea (OSA) is important to decrease postoperative events and improve cost-effectiveness. Therefore, this study aimed to compare surgical efficacy and safety between powered intracapsular tonsillectomy and adenoidectomy (PITA) and extracapsular tonsillectomy and adenoidectomy for OSA in children. METHODS: In this retrospective case-control study, patient characteristics and postoperative outcomes were compared between 93 children with OSA who underwent PITA and 81 children who underwent conventional extracapsular tonsillectomy and adenoidectomy at a tertiary hospital. Data analysis using multivariate, multiple regression, and binomial logistic regression analyses was performed. RESULTS: PITA reduced the odds of postoperative hemorrhage by 8.95% (odds ratio [OR]: 5.69, p = 0.013) and of secondary hemorrhage by 8.8% (OR: 10.08, p = 0.006), decreased postoperative analgesia use by 0.35% (p < 0.001), and increased oral intake on postoperative day 1 by 17% (p < 0.001). There were no significant differences in early hemorrhage or regrowth rates between the groups. CONCLUSION: PITA could reduce the risk of secondary hemorrhage and improve postoperative quality of life, which are ideal clinical benefits of surgery in pediatric patients with OSA.

Deletion of CD38 and supplementation of NAD+ attenuate axon degeneration in a mouse facial nerve axotomy model.

Following facial nerve axotomy, nerve function is not fully restored even after reconstruction. This may be attributed to axon degeneration/neuronal death and sustained neuroinflammation. CD38 is an enzyme that catalyses the hydrolysis of nicotinamide adenine dinucleotide (NAD+) and is a candidate molecule for regulating neurodegeneration and neuroinflammation. In this study, we analyzed the effect of CD38 deletion and NAD+ supplementation on neuronal death and glial activation in the facial nucleus in the brain stem, and on axon degeneration and immune cell infiltration in the distal portion of the facial nerve after axotomy in mice. Compared with wild-type mice, CD38 knockout (KO) mice showed reduced microglial activation in the facial nucleus, whereas the levels of neuronal death were not significantly different. In contrast, the axon degeneration and demyelination were delayed, and macrophage accumulation was reduced in the facial nerve of CD38 KO mice after axotomy. Supplementation of NAD+ with nicotinamide riboside slowed the axon degeneration and demyelination, although it did not alter the level of macrophage infiltration after axotomy. These results suggest that CD38 deletion and supplementation of NAD+ may protect transected axon cell-autonomously after facial nerve axotomy.

Microglial activation in the cochlear nucleus after early hearing loss in rats.

OBJECTIVE: Microglia are highly specialized tissue macrophages in the central nervous system. Their activation in the auditory system has been reported in adult hearing loss models, but their status in the developing auditory system is less understood. Therefore, we investigated microglial status in the cochlear nucleus (CN) during normal developing periods and after exposing rats to amikacin, a potent ototoxin, around the time of hearing onset. METHODS: To develop the deafness model, rats were administered with a daily intraperitoneal injection of amikacin (500 mg/kg) from postnatal day 7 (P7) to P15. To evaluate the expression of ionized calcium binding adaptor molecule 1 (Iba1), we performed immunohistochemical analysis using rat brains from P10-60. To compare the expression of microglia-related gene, reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis were performed. RESULTS: Immunohistochemical analysis revealed that, under normal conditions, microglia had relatively large cell bodies with several extended processes that surrounded other cells at P10, while the sizes and number of these cells gradually decreased afterward. In contrast, when amikacin was administered from P7 to P15, microglia maintained large cell bodies with relatively shorter processes at both P15 and P21. Furthermore, RT-qPCR analysis revealed upregulation of genes including phagocytotic and anti-inflammatory markers after amikacin administration. CONCLUSION: These results suggest that microglia are activated in the CN, and they may contribute to tissue remodeling after early hearing loss in the developing auditory system.

Endoscopic management of petrous apex cholesteatoma.

We describe a technique for approaching petrous apex cholesteatoma using combined lateral microscopic/endoscopic approaches, and discuss the utility of endoscopy in managing matrix inside the petrous apex. In our two cases, total view inside the petrous apex was achieved under endoscopy without mobilizing the internal carotid artery, and the matrix was successfully removed. Neither patient has presented with postoperative recurrence thanks to the wide-angle endoscopic view inside the petrous apex. Since the number of patients was small, comparisons with microscopic treatments are not yet valid, but endoscopes could offer a helpful tool for operating inside the petrous apex.

Cochlear implantation in deaf patients with eosinophilic otitis media using subtotal petrosectomy and mastoid obliteration.

We investigated the usefulness and safety of our cochlear implantation method for two deaf patients with eosinophilic otitis media. The surgical approach was a subtotal petrosectomy to remove the theater of eosinophilic infiltration and to prevent leaching of foreign substances and entry of stimuli that are the cause of eosinophilic inflammations. The operative cavity was obliterated with abdominal fat. There were no complications or recurrent inflammation following surgery in the cases of both patients. It was confirmed by CT scan that the eustachian tube was closed and the operative cavity remained obliterated with abdominal fat. Following the procedure, the hearing threshold results of the two patients were 30 and 34 dB. Cochlear implantation procedures in this report for deaf patients resulting from eosinophilic otitis media may be effective and safe. Using steroids before surgery may be the better option. To further confirm the efficacy and safety of our surgical concept, we need to administer this treatment concept for a large number of cases in a future study.

Soft-wall reconstruction of the canal wall with retrograde bone work for pediatric cholesteatoma: Long-term results.

OBJECTIVE: To retrospectively evaluate the long-term results of surgery for retrograde bone work, using soft-wall reconstruction of the canal wall, for pediatric cholesteatoma. METHODS: We retrospectively evaluated a series of 25 consecutive ears of 24 patients who were ≤16 years of age. All children underwent cholesteatoma surgery between October 2002 and August 2008. The type of cholesteatoma, the length of follow-up, the incidence of residual and recurrent cholesteatoma, postoperative hearing results, and the form of the reconstructed external canal wall and tympanic membrane were assessed. RESULTS: There were 21 males and 3 females. The procedure was performed on both ears of one patient who had bilateral congenital cholesteatoma (CC). At the initial surgery, 16 cases (64%) had CC and nine (36%) had acquired cholesteatoma (AC). The mean age at surgery was 8.2 years and 10.4 years for CC and AC cases, respectively. The mean postoperative follow-up period after the initial surgery was 90 months for CC cases and 108 months for AC cases. Cholesteatoma recurrence occurred for 6% and 56% of cases with CC and AC, respectively. Successful serviceable hearing was achieved for 93.8% with CC and 100% with AC. Cases with inadequate hearing after surgery were characterized by disease extension to the mastoid and the protympanum. The long-term forms of the reconstructed external canal wall changed depending on their middle ear aeration. Some cases of tympanic membrane perforation and otitis media with effusion were occurred during the follow-up period. CONCLUSION: Overall, the retrograde approach with soft-wall reconstruction of the canal wall achieved a low recurrence rate for cholesteatoma and good hearing outcomes during long-term follow-up for the pediatric case. However, in cases with eustachian tube dysfunction and/or cholesteatoma involving the protympanum, the hearing outcomes were less favorable.

Correlation between cyclooxygenase-2, proliferative activity, and mucin phenotype in human advanced gastric cancer.

BACKGROUND: Recent studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of gastrointestinal cancer, and that cyclooxygenase-2 (COX-2) may be a target enzyme for the prevention or regression of cancer by the use of NSAIDs. Mucin histochemistry has made possible a clear distinction between the differentiated characteristics of gastrointestinal epithelial cells, and the possibility that phenotypic shifts from gastric- to intestinal-type in gastric carcinoma progression has been suggested. To evaluate the role of COX-2 in gastric cancer progression, we immunohistochemically investigated COX-2 expression, and examined its relationship to proliferative activity, mucin phenotype, and clinicopathological parameters in human advanced gastric carcinomas. METHODS: Forty-five surgical specimens of advanced gastric carcinomas (invaded the muscularis propria or subserosa) were examined. Immunohistochemical staining was performed with monoclonal antibodies against COX-2, Ki-67, CD10 (brush border), MUC-2 (goblet-cell mucin), MUC-5AC (gastric foveolar mucin), and MUC-6 (pyloric mucin). COX-2 expression was scored by the percentage of COX-2-positive neoplastic cells, and proliferative activity was assessed by the Ki-67 labeling index at the deepest area of invasion. The mucin phenotype of the carcinomas was classified into three categories; gastric, intestinal, and unclassified. RESULTS: COX-2 staining was restricted to the cytoplasm, not only in cancer cells but also in intestinal metaplasia and some inflammatory cells and COX-2 expression in cancer cells varied greatly, but the staining in some samples was preferentially found at the invasive front. COX-2 positivity was found to correlate with Ki-67 labeling. The mean COX-2 scores were 2.29%, 2.71%, and 2.75%; and the Ki-67 labeling indices were 23.6%, 40.6%, and 56.5%, in gastric-, intestinal-, and unclassified- type carcinomas, respectively. CONCLUSIONS: A close relationship between COX-2 expression and proliferative activity was confirmed in the deepest areas of advanced gastric carcinoma, and the proliferative activity increased from gastric- to intestinal- and to unclassified- type gastric carcinoma, suggesting a role for COX-2 expression and differences in biological behavior according to mucin phenotype expression during gastric cancer progression.

Recurrence of hepatocellular carcinoma with rapid growth after spontaneous regression.

We report an 80-year-old man who presented with spontaneous regression of hepatocellular carcinoma (HCC). He complained of sudden right flank pain and low-grade fever. The level of protein induced by vitamin K antagonist (PIVKA)-II was 1 137 mAU/mL. A computed tomography scan in November 2000 demonstrated a low-density mass located in liver S4 with marginal enhancement and a cystic mass of 68 mmX55 mm in liver S6, with slightly high density content and without marginal enhancement. Angiography revealed that the tumor in S4 with a size of 25 mmX20 mm was a typical hypervascular HCC, and transarterial chemoembolization was performed. However, the tumor in S6 was hypovascular and atypical of HCC, and thus no therapy was given. In December 2000, the cystic mass regressed spontaneously to 57 mmX44 mm, and aspiration cytology revealed bloody fluid, and the mass was diagnosed cytologically as class I. The tumor in S4 was treated successfully with a 5 mm margin of safety around it. The PIVKA-II level normalized in February 2001. In July 2001, the tumor regressed further but presented with an enhanced area at the posterior margin. In November 2001, the enhanced area extended, and a biopsy revealed well-differentiated HCC, although the previous tumor in S4 disappeared. Angiography demonstrated two tumor stains, one was in S6, which was previously hypovascular, and the other was in S8. Subsequently, the PIVKA-II level started to rise with the doubling time of 2-3 wk, and the tumor grew rapidly despite repeated transarterial embolization with gel foam. In February 2003, the patient died of bleeding into the peritoneal cavity from the tumor that occupied almost the entire right lobe. Considering the acute onset of the symptoms, we speculate that local ischemia possibly due to rapid tumor growth, resulted in intratumoral bleeding and/or hemorrhagic necrosis, and finally spontaneous regression of the initial tumor in S6.

Fascin, an actin-bundling protein, modulates colonic epithelial cell invasiveness and differentiation in vitro.

In epithelial tissue, cell-matrix and cell-cell adhesive interactions have important roles in the normal organization and stabilization of the cell layer. The malignant conversion of epithelial cells involves alterations in the expression and function of these adhesion systems that enable a switch to a migratory phenotype in tumor invasion and metastasis. Fascin is an actin-crosslinking protein that is found in the core actin bundles of cell-surface spikes and projections that are implicated in cell motility. We demonstrate that fascin is not detectable in normal colonic epithelium, but is dramatically up-regulated in colorectal adenocarcinoma. To test the hypothesis that fascin could participate in tumor invasive behavior, we developed a cell culture model to examine the effect of fascin expression on the adhesive interactions, invasiveness, and differentiation of colonic epithelial cells. We report marked effects on the organization of cell-surface protrusions, actin cytoskeleton, and focal adhesions in the absence of alterations in the protein levels of the major components of these structures. These effects correlate with alterations in cell movements on two-dimensional matrix, and increased invasiveness in three-dimensional matrix. The cells also show increased proliferation and decreased capacity for normal glandular differentiation in collagen gels. We propose that up-regulation of fascin, by promoting the formation of protrusive, actin-based, cell-motility structures, could be a significant component in the acquisition of invasive phenotype in colonic carcinoma.

Effects of etodolac, a selective cyclooxygenase-2 inhibitor, on the expression of E-cadherin-catenin complexes in gastrointestinal cell lines.

BACKGROUND: Recent studies have shown that cyclooxygenase-2 (COX-2) inhibitors may participate in the proliferation of cancer cells. Because the cadherin-catenin complex is not only a key component of the adherens junction but also has been suggested to regulate cell proliferation, modulation of these molecules may be a mechanism by which COX-2 activity affects cell proliferation. In this study, we evaluated the effect of a COX-2 inhibitor on the proliferation and expression of E-cadherin-complexes in gastrointestinal cancer cell lines. METHODS: The gastrointestinal cancer cell lines Caco2, HT29, and MKN45 were grown for 24 h in the presence and absence of a selective COX-2 inhibitor, etodolac (10(-5), 10(-4), and 10(-3) M). Cell proliferation was assessed by (3)H-thymidine incorporation, and the expression of E-cadherin and catenins was assessed by Western blotting, Northern blotting, and immunofluorescence. RESULTS: Etodolac induced a significant reduction in cell proliferation in Caco2 and MKN45 cells. E-cadherin expression was upregulated after stimulation with etodolac in Caco2 cells, whereas the expression of alpha-, beta-, gamma- and p120-catenins was not modified. The expression of E-cadherin mRNA was also upregulated in Caco2 cells, and was upregulated also in MKN45 cells, which did not express normal E-cadherin protein by the use of a mouse monoclonal antibody against human E-cadherin, HECD-1 antibody. Immunofluorescence revealed that the increased E-cadherin was localized at the cytoplasmic membrane. CONCLUSIONS: The inhibition of cell growth by etodolac in Caco-2 cells was associated with a dose-dependent upregulation and intense cytoplasmic localization of E-cadherin. No quantitative change in catenin expression was found in this phenomenon. These findings suggest that the COX-2 inhibitor affects the transcription of E-cadherin, or that there may be some homeostatic link between the cell cycle and E-cadherin transcription.