Synchronous occurrence of oral squamous cell carcinoma and Warthin's tumor: systematic review and case report.

We systematically reviewed the literature on the co-occurrence of squamous cell carcinoma (SCC) and Warthin's tumor (WT), thought to be quite rare, to help reduce misdiagnosis and improve treatment planning. For this systematic review, we searched for articles in the Web of Science and PubMed databases, analyzed relevant studies for forward and backward citations, and identified only articles reporting on the "co-occurrence" of WT and SCC. Of the 237 studies identified, 12 comprising 18 patients met the inclusion criteria, to which we added one study from our institution. Most WTs were associated with SCC in the parotid gland or cervical lymph nodes. Most patients (89.5%) underwent selective or radical neck dissection due to identification of lesions separate from the primary SCC. Despite its frequent co-occurrence with other neoplasms, WT in the parotid or cervical lymph nodes tends to be misdiagnosed as a metastatic node when SCC is observed as the primary tumor. Factors to consider in diagnosis and neck management include identification of an association other than growth or development by lymphangiogenesis and whether the patient is a smoker, a strong risk factor.

Radiomics-based sialadenitis staging in contrast-enhanced computed tomography and ultrasonography: a preliminary rat model study.

OBJECTIVE: The aim of this study was to measure the ability of radiomics analysis to diagnose different stages of sialadenitis, compare the diagnostic accuracy of computed tomography (CT) and ultrasonography (US), and suggest radiomics features selected through 3 machine learning algorithms that would be helpful in discriminating between stages of sialadenitis with both imaging systems. STUDY DESIGN: Wistar rats were treated to induce acute and chronic sialadenitis in the left and right submandibular glands, respectively. Contrast-enhanced CT and US of the glands were performed, followed by extirpation and histopathologic confirmation. Radiomics feature values of the glands were obtained from all images. Based on 3 feature selection methods, an optimal feature set was defined after a comparison of the receiver operating characteristic area under the curve (AUC) of each combination of 3 deep learning algorithms and 3 classification models. RESULTS: The attribute features for the CT model were 2 gray-level run length matrices and 2 gray-level zone length matrices. In the US model, there were 2 gray-level co-occurrence matrices and 2 gray-level zone length matrices. The most accurate diagnostic models of CT and US yielded outstanding (AUC = 1.000) and excellent (AUC = 0.879) discrimination, respectively. CONCLUSIONS: The radiomics diagnostic model using gray-level zone length matrices-based features conferred clinically outstanding discriminating ability among stages of sialadenitis using CT and excellent discrimination with US in almost all combinations of machine learning feature selections and classification models.

Standard operating procedures for the collection, processing, and storage of oral biospecimens at the Korea Oral Biobank Network.

PURPOSE: The Korea Oral Biobank Network (KOBN) was established in 2021 as a branch of the Korea Biobank Network under the Korea Centers for Disease Control and Prevention to provide infrastructure for the collection, management, storage, and utilization of human bioresources from the oral cavity and associated clinical data for basic research and clinical studies. METHODS: To address the need for the unification of the biobanking process, the KOBN organized the concept review for all the processes. RESULTS: The KOBN established standard operating procedures for the collection, processing, and storage of oral samples. CONCLUSIONS: The importance of collecting high-quality bioresources to generate accurate and reproducible research results has always been emphasized. A standardized procedure is a basic prerequisite for implementing comprehensive quality management of biological resources and accurate data production.

Glycogen Synthase Kinase-3 Interaction Domain Enhances Phosphorylation of SARS-CoV-2 Nucleocapsid Protein.

A structural protein of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), nucleocapsid (N) protein is phosphorylated by glycogen synthase kinase (GSK)-3 on the serine/arginine (SR) rich motif located in disordered regions. Although phosphorylation by GSK-3ß constitutes a critical event for viral replication, the molecular mechanism underlying N phosphorylation is not well understood. In this study, we found the putative alpha-helix L/FxxxL/AxxRL motif known as the GSK-3 interacting domain (GID), found in many endogenous GSK-3ß binding proteins, such as Axins, FRATs, WWOX, and GSKIP. Indeed, N interacts with GSK-3ß similarly to Axin, and Leu to Glu substitution of the GID abolished the interaction, with loss of N phosphorylation. The N phosphorylation is also required for its structural loading in a virus-like particle (VLP). Compared to other coronaviruses, N of Sarbecovirus lineage including bat RaTG13 harbors a CDK1-primed phosphorylation site and Gly-rich linker for enhanced phosphorylation by GSK-3ß. Furthermore, we found that the S202R mutant found in Delta and R203K/G204R mutant found in the Omicron variant allow increased abundance and hyper-phosphorylation of N. Our observations suggest that GID and mutations for increased phosphorylation in N may have contributed to the evolution of variants.

Case Report: Papillary Lesions at the Mouth Floor May Mimic Sialadenoma Papilliferum.

Salivary gland tumor Sialadenoma papilliferum (SialP) clinically resembles papillary epithelial lesions, such as squamous papilloma (SqP) or verrucous leukoplakia. Pathological sampling including an adequate depth of both the mucosa and submucosa layer is required for discrimination between the diseases. Though ductal proliferation in the submucosa is characteristic in SialP, papillary lesions arising at the mouth floor, specifically near the ductal orifice, are more problematic. Salivary gland ductal ectasia, along with the overlying papillary hyperplasia, may mimic the biphasic tumorous growth pattern of SialP, making discrimination extremely difficult. Further cellular dysplasia in the papillary mucosal lesion raises the possibility of malignant transformation in a known benign lesion, SialP. Herein, we present a case of SqP at the mouth floor which mimicked both clinical and pathological features of SialP and compared it with a definite case of SialP. Moreover, we discuss major differential points that clinicians and pathologists should consider during diagnosis of oral papillary lesions arising near the salivary glands.

Risk Factors of Microscopically Tumor-Free Surgical Margins for Recurrence and Survival of Oral Squamous Cell Carcinoma Patients.

Objectives: The concept of adequate surgical margins remains controversial in oral squamous cell carcinoma (OSCC) surgery. This study aimed to identify surgical margin-related indicators that might impact recurrence and survival of OSCC patients. Materials and Methods: Histopathological examination was performed using hematoxylin-eosin-stained surgical margin tissue sections in 235 OSCC patients. Axin2 and Snail expression at the surgical margin was detected by immunohistochemistry. The impact of the Axin2-Snail cascade on tumorigenesis of the immortalized human oral keratinocyte (IHOK) line was investigated in vivo. Results: The width and dysplasia of surgical margins were not significantly associated with the outcome of OSCC patients. In a multivariate analysis using variable clinicopathologic factors and with Axin2 and Snail expression as cofactors, higher age (hazard ratio [HR]:1.050; P=0.047), Axin2 (HR:6.883; P=0.014), and Snail abundance (HR:5.663; P=0.009) had independent impacts on worsened overall survival. Similarly, lesion site in retromolar trigone (HR:4.077; P=0.010), upper (HR:4.332; P=0.005) and lower gingiva (HR:3.545; P=0.012), presence of extranodal extension (HR:9.967; P<0.001), perineural invasion (HR:3.627; P=0.024), and Snail abundance (HR:3.587; P<0.001) had independent impacts on worsened recurrence-free survival. Furthermore, Axin2 knockdown induced decreased Snail expression and attenuated tumorigenesis in the IHOK line. Conclusion: Histopathological examination of surgical margins may not be reliable to predict OSCC patient outcome. Molecular analysis may provide a more accurate risk assessment of surgical margins in OSCC. In particular, Axin2 and Snail are potential predictive biomarkers for the risk assessment of surgical margins in OSCC.

Direct Contact with Platelets Induces Podoplanin Expression and Invasion in Human Oral Squamous Cell Carcinoma Cells.

Oral squamous cell carcinoma (OSCC) is mostly diagnosed at an advanced stage, with local and/or distal metastasis. Thus, locoregional and/or local control of the primary tumor is crucial for a better prognosis in patients with OSCC. Platelets have long been considered major players in cancer metastasis. Traditional antiplatelet agents, such as aspirin, are thought to be potential chemotherapeutics, but they need to be used with caution because of the increased bleeding risk. Podoplanin (PDPN)-expressing cancer cells can activate platelets and promote OSCC metastasis. However, the reciprocal effect of platelets on PDPN expression in OSCC has not been investigated. In this study, we found that direct contact with platelets upregulated PDPN and integrin ß1 at the protein level and promoted invasiveness of human OSCC Ca9.22 cells that express low levels of PDPN. In another human OSCC HSC3 cell line that express PDPN at an abundant level, silencing of the PDPN gene reduced cell invasiveness. Analysis of the public database further supported the co-expression of PDPN and integrin ß1 and their increased expression in metastatic tissues compared to normal and tumor tissues of the oral cavity. Taken together, these data suggest that PDPN is a potential target to regulate platelet-tumor interaction and metastasis for OSCC treatment, which can overcome the limitations of traditional antiplatelet drugs.

Longitudinal detection of somatic mutations in saliva and plasma for the surveillance of oral squamous cell carcinomas.

PURPOSES: Although clinical and radiological examinations can be used to diagnose oral cancer, and surgical pathology remains the gold standard, these conventional methods have limitations. We evaluated the feasibility of longitudinal next-generation sequencing-based liquid biopsy for oral squamous cell carcinoma surveillance. MATERIALS AND METHODS: Eleven patients were enrolled, and plasma and saliva were collected before, and 1, 3, and 6 months after surgery. Tumor-specific mutations were selected using paired, whole-exome analyses of tumor tissues and whole blood. Genes frequently mutated in head and neck cancer were identified using the Cancer Genome Atlas (TCGA) and Catalogue of Somatic Mutations in Cancer (COSMIC) databases to design targeted deep sequencing panels. RESULTS: In five of the six patients with recurrent cancer, circulating tumor DNA (ctDNA) was detected earlier with liquid biopsy than with conventional monitoring techniques. Moreover, patients without recurrence exhibited decreased ctDNA allele frequency post-treatment. CONCLUSIONS: Longitudinal liquid biopsy of plasma and saliva may be feasible for detecting somatic mutations associated with oral squamous cell carcinomas. It might be attributable to determine early tumor recurrence through genetic analysis of ctDNA.

Metformin and Niclosamide Synergistically Suppress Wnt and YAP in APC-Mutated Colorectal Cancer.

The Wnt and Hippo pathways are tightly coordinated and understanding their reciprocal regulation may provide a novel therapeutic strategy for cancer. Anti-helminthic niclosamide is an effective inhibitor of Wnt and is now in a phase II trial for advanced colorectal cancer (CRC) patients. We found that Axin2, an authentic target gene of canonical Wnt, acts as aYAP phosphorylation activator in APC-mutated CRC. While niclosamide effectively suppresses Wnt, it also inhibits Hippo, limiting its therapeutic potential for CRC. To overcome this limitation, we utilized metformin, a clinically available AMPK activator. This combinatory approach not only suppresses canonical Wnt activity, but also inhibits YAP activity in CRC cancer cells and in patient-derived cancer organoid through the suppression of cancer stemness. Further, combinatory oral administration suppressed in vivo tumorigenesis and the cancer progression of APC-MIN mice models. Our observations provide not only a reciprocal link between Wnt and Hippo, but also clinically available novel therapeutics that are able to target Wnt and YAP in APC-mutated CRC.

Platelet CLEC2-Podoplanin Axis as a Promising Target for Oral Cancer Treatment.

Cancer tissues are not just simple masses of malignant cells, but rather complex and heterogeneous collections of cellular and even non-cellular components, such as endothelial cells, stromal cells, immune cells, and collagens, referred to as tumor microenvironment (TME). These multiple players in the TME develop dynamic interactions with each other, which determines the characteristics of the tumor. Platelets are the smallest cells in the bloodstream and primarily regulate blood coagulation and hemostasis. Notably, cancer patients often show thrombocytosis, a status of an increased platelet number in the bloodstream, as well as the platelet infiltration into the tumor stroma, which contributes to cancer promotion and progression. Thus, platelets function as one of the important stromal components in the TME, emerging as a promising chemotherapeutic target. However, the use of traditional antiplatelet agents, such as aspirin, has limitations mainly due to increased bleeding complications. This requires to implement new strategies to target platelets for anti-cancer effects. In oral squamous cell carcinoma (OSCC) patients, both high platelet counts and low tumor-stromal ratio (high stroma) are strongly correlated with increased metastasis and poor prognosis. OSCC tends to invade adjacent tissues and bones and spread to the lymph nodes for distant metastasis, which is a huge hurdle for OSCC treatment in spite of relatively easy access for visual examination of precancerous lesions in the oral cavity. Therefore, locoregional control of the primary tumor is crucial for OSCC treatment. Similar to thrombocytosis, higher expression of podoplanin (PDPN) has been suggested as a predictive marker for higher frequency of lymph node metastasis of OSCC. Cumulative evidence supports that platelets can directly interact with PDPN-expressing cancer cells via C-type lectin-like receptor 2 (CLEC2), contributing to cancer cell invasion and metastasis. Thus, the platelet CLEC2-PDPN axis could be a pinpoint target to inhibit interaction between platelets and OSCC, avoiding undesirable side effects. Here, we will review the role of platelets in cancer, particularly focusing on CLEC2-PDPN interaction, and will assess their potentials as therapeutic targets for OSCC treatment.

Micellized Protein Transduction Domain-Bone Morphogenetic Protein-7 Efficiently Blocks Renal Fibrosis Via Inhibition of Transforming Growth Factor-Beta-Mediated Epithelial-Mesenchymal Transition.

Tubulointerstitial renal fibrosis is a chronic disease process affecting chronic kidney disease (CKD). While the etiological role of transforming growth factor-beta (TGF-ß) is well known for epithelial-mesenchymal transition (EMT) in chronic kidney disease, effective therapeutics for renal fibrosis are largely limited. As a member of the TGF-ß superfamily, bone morphogenetic protein-7 (BMP-7) plays an important role as an endogenous antagonist of TGF-ß, inhibiting fibrotic progression in many organs. However, soluble rhBMP-7 is hardly available for therapeutics due to its limited pharmacodynamic profile and rapid clearance in clinical settings. In this study, we have developed a novel therapeutic approach with protein transduction domain (PTD) fused BMP-7 in micelle (mPTD-BMP-7) for long-range signaling in vivo. Contrary to rhBMP-7 targeting its cognate receptors, the nano-sized mPTD-BMP-7 is transduced into cells through an endosomal pathway and secreted to the exosome having active BMP-7. Further, transduced mPTD-BMP-7 successfully activates SMAD1/5/8 and inhibits the TGF-ß-mediated epithelial-mesenchymal transition process in vitro and in an in vivo unilateral ureter obstruction model. To determine the clinical relevance of our strategy, we also developed an intra-arterial administration of mPTD-BMP-7 through renal artery in pigs. Interestingly, mPTD-BMP-7 through renal artery intervention effectively delivered into Bowman's space and inhibits unilateral ureter obstruction-induced renal fibrosis in pigs. Our results provide a novel therapeutic targeting TGF-ß-mediated renal fibrosis and other organs as well as a clinically available approach for kidney.

TGF-ß Pathway in Salivary Gland Fibrosis.

Fibrosis is presented in various physiologic and pathologic conditions of the salivary gland. Transforming growth factor beta (TGF-ß) pathway has a pivotal role in the pathogenesis of fibrosis in several organs, including the salivary glands. Among the TGF-ß superfamily members, TGF-ß1 and 2 are pro-fibrotic ligands, whereas TGF-ß3 and some bone morphogenetic proteins (BMPs) are anti-fibrotic ligands. TGF-ß1 is thought to be associated with the pro-fibrotic pathogenesis of sialadenitis, post-radiation salivary gland dysfunction, and Sjögren's syndrome. Potential therapeutic strategies that target multiple levels in the TGF-ß pathway are under preclinical and clinical research for fibrosis. Despite the anti-fibrotic effect of BMPs, their in vivo delivery poses a challenge in terms of adequate clinical efficacy. In this article, we will review the relevance of TGF-ß signaling in salivary gland fibrosis and advances of potential therapeutic options in the field.

Breast Cancer Subtypes Underlying EMT-Mediated Catabolic Metabolism.

Efficient catabolic metabolism of adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) is essentially required for cancer cell survival, especially in metastatic cancer progression. Epithelial-mesenchymal transition (EMT) plays an important role in metabolic rewiring of cancer cells as well as in phenotypic conversion and therapeutic resistance. Snail (SNAI1), a well-known inducer of cancer EMT, is critical in providing ATP and NADPH via suppression of several gatekeeper genes involving catabolic metabolism, such as phosphofructokinase 1 (PFK1), fructose-1,6-bisphosphatase 1 (FBP1), and acetyl-CoA carboxylase 2 (ACC2). Paradoxically, PFK1 and FBP1 are counter-opposing and rate-limiting reaction enzymes of glycolysis and gluconeogenesis, respectively. In this study, we report a distinct metabolic circuit of catabolic metabolism in breast cancer subtypes. Interestingly, PFKP and FBP1 are inversely correlated in clinical samples, indicating different metabolic subsets of breast cancer. The luminal types of breast cancer consist of the pentose phosphate pathway (PPP) subset by suppression of PFKP while the basal-like subtype (also known as triple negative breast cancer, TNBC) mainly utilizes glycolysis and mitochondrial fatty acid oxidation (FAO) by loss of FBP1 and ACC2. Notably, PPP remains active via upregulation of TIGAR in the FBP1-loss basal-like subset, indicating the importance of PPP in catabolic cancer metabolism. These results indicate different catabolic metabolic circuits and thus therapeutic strategies in breast cancer subsets.

Snail augments fatty acid oxidation by suppression of mitochondrial ACC2 during cancer progression.

Despite the importance of mitochondrial fatty acid oxidation (FAO) in cancer metabolism, the biological mechanisms responsible for the FAO in cancer and therapeutic intervention based on catabolic metabolism are not well defined. In this study, we observe that Snail (SNAI1), a key transcriptional repressor of epithelial-mesenchymal transition, enhances catabolic FAO, allowing pro-survival of breast cancer cells in a starved environment. Mechanistically, Snail suppresses mitochondrial ACC2 (ACACB) by binding to a series of E-boxes located in its proximal promoter, resulting in decreased malonyl-CoA level. Malonyl-CoA being a well-known endogenous inhibitor of fatty acid transporter carnitine palmitoyltransferase 1 (CPT1), the suppression of ACC2 by Snail activates CPT1-dependent FAO, generating ATP and decreasing NADPH consumption. Importantly, combinatorial pharmacologic inhibition of pentose phosphate pathway and FAO with clinically available drugs efficiently reverts Snail-mediated metabolic reprogramming and suppresses in vivo metastatic progression of breast cancer cells. Our observations provide not only a mechanistic link between epithelial-mesenchymal transition and catabolic rewiring but also a novel catabolism-based therapeutic approach for inhibition of cancer progression.

Exosome-based delivery of super-repressor IκBα relieves sepsis-associated organ damage and mortality.

As extracellular vesicles that play an active role in intercellular communication by transferring cellular materials to recipient cells, exosomes offer great potential as a natural therapeutic drug delivery vehicle. The inflammatory responses in various disease models can be attenuated through introduction of super-repressor IκB (srIκB), which is the dominant active form of IκBα and can inhibit translocation of nuclear factor κB into the nucleus. An optogenetically engineered exosome system (EXPLOR) that we previously developed was implemented for loading a large amount of srIκB into exosomes. We showed that intraperitoneal injection of purified srIκB-loaded exosomes (Exo-srIκBs) attenuates mortality and systemic inflammation in septic mouse models. In a biodistribution study, Exo-srIκBs were observed mainly in the neutrophils, and in monocytes to a lesser extent, in the spleens and livers of mice. Moreover, we found that Exo-srIκB alleviates inflammatory responses in monocytic THP-1 cells and human umbilical vein endothelial cells.

Loss of SLC25A11 causes suppression of NSCLC and melanoma tumor formation.

BACKGROUND: Fast growing cancer cells require greater amounts of ATP than normal cells. Although glycolysis was suggested as a source of anabolic metabolism based on lactate production, the main source of ATP to support cancer cell metabolism remains unidentified. METHODS: We have proposed that the oxoglutarate carrier SLC25A11 is important for ATP production in cancer by NADH transportation from the cytosol to mitochondria as a malate. We have examined not only changes of ATP and NADH but also changes of metabolites after SLC25A11 knock down in cancer cells. FINDINGS: The mitochondrial electron transport chain was functionally active in cancer cells. The cytosolic to mitochondrial NADH ratio was higher in non-small cell lung cancer (NSCLC) and melanoma cells than in normal cells. This was consistent with higher levels of the oxoglutarate carrier SLC25A11. Blocking malate transport by knockdown of SLC25A11 significantly impaired ATP production and inhibited the growth of cancer cells, which was not observed in normal cells. In in vivo experiments, heterozygote of SLC25A11 knock out mice suppressed KRASLA2 lung tumor formation by cross breeding. INTERPRETATION: Cancer cells critically depended on the oxoglutarate carrier SLC25A11 for transporting NADH from cytosol to mitochondria as a malate form for the purpose of ATP production. Therefore blocking SLC25A11 may have an advantage in stopping cancer growth by reducing ATP production. FUND: The Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT to SYK (NRF-2017R1A2B2003428).

Therapeutic implications of cancer epithelial-mesenchymal transition (EMT).

The epithelial-mesenchymal transition (EMT) comprises an essential biological process involving cancer progression as well as initiation. While the EMT has been regarded as a phenotypic conversion from epithelial to mesenchymal cells, recent evidence indicates that it plays a critical role in stemness, metabolic reprogramming, immune evasion and therapeutic resistance of cancer cells. Interestingly, several transcriptional repressors including Snail (SNAI1), Slug (SNAI2) and the ZEB family constitute key players for EMT in cancer as well as in the developmental process. Note that the dynamic conversion between EMT and epithelial reversion (mesenchymal-epithelial transition, MET) occurs through variable intermediate-hybrid states rather than being a binary process. Given the close connection between oncogenic signaling and EMT repressors, the EMT has emerged as a therapeutic target or goal (in terms of MET reversion) in cancer therapy. Here we review the critical role of EMT in therapeutic resistance and the importance of EMT as a therapeutic target for human cancer.

Dishevelled has a YAP nuclear export function in a tumor suppressor context-dependent manner.

Phosphorylation-dependent YAP translocation is a well-known intracellular mechanism of the Hippo pathway; however, the molecular effectors governing YAP cytoplasmic translocation remains undefined. Recent findings indicate that oncogenic YAP paradoxically suppresses Wnt activity. Here, we show that Wnt scaffolding protein Dishevelled (DVL) is responsible for cytosolic translocation of phosphorylated YAP. Mutational inactivation of the nuclear export signal embedded in DVL leads to nuclear YAP retention, with an increase in TEAD transcriptional activity. DVL is also required for YAP subcellular localization induced by E-cadherin, α-catenin, or AMPK activation. Importantly, the nuclear-cytoplasmic trafficking is dependent on the p53-Lats2 or LKB1-AMPK tumor suppressor axes, which determine YAP phosphorylation status. In vivo and clinical data support that the loss of p53 or LKB1 relieves DVL-linked reciprocal inhibition between the Wnt and nuclear YAP activity. Our observations provide mechanistic insights into controlled proliferation coupled with epithelial polarity during development and human cancer.

The Pentose Phosphate Pathway as a Potential Target for Cancer Therapy.

During cancer progression, cancer cells are repeatedly exposed to metabolic stress conditions in a resource-limited environment which they must escape. Increasing evidence indicates the importance of nicotinamide adenine dinucleotide phosphate (NADPH) homeostasis in the survival of cancer cells under metabolic stress conditions, such as metabolic resource limitation and therapeutic intervention. NADPH is essential for scavenging of reactive oxygen species (ROS) mainly derived from oxidative phosphorylation required for ATP generation. Thus, metabolic reprogramming of NADPH homeostasis is an important step in cancer progression as well as in combinational therapeutic approaches. In mammalian, the pentose phosphate pathway (PPP) and one-carbon metabolism are major sources of NADPH production. In this review, we focus on the importance of glucose flux control towards PPP regulated by oncogenic pathways and the potential therein for metabolic targeting as a cancer therapy. We also summarize the role of Snail (Snai1), an important regulator of the epithelial mesenchymal transition (EMT), in controlling glucose flux towards PPP and thus potentiating cancer cell survival under oxidative and metabolic stress.