PAK4 inhibition augments anti-tumour effect by immunomodulation in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumours, warranting novel treatments. Here, we examined the therapeutic efficacy of inhibiting p21 activated kinase 4 (PAK4) in OSCC and determined its immunomodulatory effect by focusing on the enhancement of anti-tumour effects. We examined PAK4 expression in OSCC cells and human clinical samples and analysed the proliferation and apoptosis of OSCC cells following PAK4 inhibition in vitro. We also investigated the effects of in vivo administration of a PAK4 inhibitor on immune cell distribution and T-cell immune responses in OSCC tumour-bearing mice. PAK4 was detected in all OSCC cells and OSCC tissue samples. PAK4 inhibitor reduced the proliferation of OSCC cells and induced apoptosis. PAK4 inhibitor significantly attenuated tumour growth in mouse and was associated with increased proportions of IFN-γ-producing CD8+ T-cells. Furthermore, PAK4 inhibitor increased the number of dendritic cells (DCs) and up-regulated the surface expression of various lymphocyte co-stimulatory molecules, including MHC-class I molecules, CD80, CD83, CD86, and CD40. These DCs augmented CD8+ T-cell activation upon co-culture. Our results suggest that PAK4 inhibition in OSCC can have direct anti-tumour and immunomodulatory effects, which might benefit the treatment of this malignancy.

Rapamycin Induces Phenotypic Alterations in Oral Cancer Cells That May Facilitate Antitumor T Cell Responses.

OBJECTIVES: In this study, we investigated the antitumor immunomodulatory effects of rapamycin in oral cancer. STUDY DESIGN: We examined the proliferation, apoptosis, and migration of cancer cells and investigated the cell surface expression levels of immune accessory molecules and T cell immune responses in vitro. We investigated the effect of in vivo administration of rapamycin on immune cell distribution and T cell immune responses in oral tumor-bearing mice. RESULTS: Rapamycin treatment significantly inhibited OSCC cell proliferation and migration, increased apoptotic cell death, and upregulated cell surface expression of several immune accessory and adhesion molecules, including CD40, CD83, PD-L1, PD-L2, MHC class I, P-selectin, and VCAM-1. These cancer cells augmented T cell proliferation. In vivo rapamycin administration significantly attenuated mouse tumor growth with an increased proportion of immune cells, including CD4+ T cells, CD8+ T cells, and dendritic cells (DCs); decreased the proportion of immune suppressive cells, such as myeloid-derived suppressor cells and regulatory T cells; enhanced DC maturation and upregulated the surface expression of CD40, CD86, and ICAM-1. CONCLUSIONS: Our results suggest that the therapeutic effect of mTOR inhibition in oral cancer can cause direct antitumor and immunomodulatory effects.

Presurgical imaging of the subscapular artery with three-dimensional-computed tomography angiography: Application to harvesting subscapular system free-flaps.

A subscapular system free-flap is extremely useful for maxillofacial reconstruction since it facilitates the simultaneous harvesting of multiple flaps using one subscapular artery (SSA) alone. However, cases of aberrations in the SSAs have been reported. Therefore, the morphology of SSA needs to be confirmed preoperatively before harvesting the flaps. Recent developments in imaging, such as three-dimensional (3D) computed tomography angiography (3D CTA), facilitate obtain high-quality images of blood vessel images. Therefore, we examined the utility of 3D CTA in navigating the course of the SSA before harvesting subscapular system free-flaps. We examined the morphology and aberrations of the SSA using 39 sides of the 3D CTA data and 22 sides of Japanese cadavers. SSAs can be classified into types S, I, P, and A. Type S SSAs are significantly long (mean length = 44.8 mm). Types I and P SSAs have short mean lengths, measuring ≤2 cm in approximately 50% of cases. In type A, the SSA is absent. The frequency of types S, I, P, and A SSAs were 28.2%, 7.7%, 51.3%, and 12.8%, respectively. Type S can be advantageous for harvesting the SSA in subscapular system free-flaps, because it is significantly longer. In contrast, types I and P might be dangerous because their mean lengths are shorter. In type A, caution is needed not to injure the axillary artery because the SSA is absent. When surgeons need to harvest the SSA, presurgical 3D CTA is recommended.

Complete Response to Cetuximab Plus Paclitaxel Therapy in Nivolumab-Refractory Patients in Distant Metastasis of Squamous Cell Carcinoma of the Tongue: A Report of Two Cases.

Herein, we report two cases of patients diagnosed with nivolumab-refractory distant metastatic squamous cell carcinoma of the tongue who were successfully treated with a combination of paclitaxel and cetuximab. Case 1 had controllable local recurrence and distant metastasis. Case 2 had controllable distant metastatic disease. Thus, demonstrating that some nivolumab-refractory patients with recurrent or distant metastatic oral squamous cell carcinoma may benefit from subsequent salvage chemotherapy.

Successful treatment with nivolumab in a patient with unresectable oral squamous cell carcinoma following ineffective chemoradiotherapy.

Key clinical message: Nivolumab has been clinically successful in prolonging the overall survival of patients with recurrent and metastatic head and neck cancer, complete remission is rare. Synergistic combinations of immunotherapy and conventional cancer treatments, such as radiotherapy or chemotherapy, are likely to be the most viable strategies for improving patient responses. Abstract: Immune checkpoint inhibitors have revolutionized recurrent, metastatic oral cancer treatment; however complete remission in advanced stages is unusual. We present a case of complete remission of advanced oral squamous cell carcinoma for >4 years in a 64-year-old Japanese woman, that responded poorly to chemoradiotherapy but well to subsequent nivolumab treatment.

Hospital pharmacist interventions for the management of oral mucositis in patients with head and neck cancer receiving chemoradiotherapy: a multicenter, prospective cohort study.

PURPOSE: Oral mucositis is a severe adverse event in patients with head and neck cancer (HNC) receiving chemotherapy and radiotherapy that may cause the termination of cancer treatment. In this study, we aimed to reveal the benefits of pharmacist interventions in oral health care for patients with HNC receiving concurrent chemoradiotherapy (CCRT). METHODS: We conducted a multicenter, prospective cohort study on 173 patients from September 2019 to August 2022. We evaluated the association between the occurrence of oral mucositis during CCRT and various factors in the absence or presence of direct medication instructions from hospital pharmacists. RESULTS: Sixty-eight patients received medication instructions from pharmacists (the pharmacist intervention group), whereas 105 patients did not receive instructions (the control group). Logistic regression analysis showed that grade 2 (Gr 2) oral mucositis was significantly lower in patients receiving pharmacist interventions than in patients in the control group (adjusted odds ratio [aOR], 0.42; 95% confidence interval [CI], 0.18-0.96; P = 0.04). The time to onset of Gr 2 oral mucositis was significantly longer in the pharmacist intervention group than in the control group (hazard ratio, 0.53; 95% CI, 0.29-0.97; P = 0.04). CONCLUSION: Direct intervention, especially when provided by hospital pharmacists, can have a real effect in supporting patients with HNC experiencing severe side effects of treatments. Moreover, the integration of pharmacists into the oral healthcare team is becoming even more essential to reduce the severity of side effects.

The EGF/EGFR axis and its downstream signaling pathways regulate the motility and proliferation of cultured oral keratinocytes.

We previously reported that the cell and colony motion of oral keratinocytes are correlated with proliferative capacity, and speculated that this may be a specific index for monitoring cell quality. However, how cell motility and proliferation are regulated by signaling pathways remains unelucidated. Here, we found that the regulation of cell motility and proliferative capacity of oral keratinocytes can be attributed to the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) axis. The EGFR downstream cascade involving the Src/PI3K/Akt/mTOR signaling pathway showed a major effect on cell motility and proliferative capacity in oral keratinocytes. Furthermore, both EGFR and Src attenuated E-cadherin expression. Taken together, these findings provide a potential basis for future quality control of cells for therapeutic use.

Neutrophil-to-lymphocyte ratio as an early marker of outcomes in patients with recurrent oral squamous cell carcinoma treated with nivolumab.

The immune checkpoint inhibitor (ICI), nivolumab, has revolutionised the treatment of recurrent and metastatic oral cancer. However, the response rate to ICIs remains low, and identifying predictors of nivolumab response is critical. Although the neutrophil-to-lymphocyte ratio (NLR) has been suggested as a predictive marker of nivolumab response in patients with various types of cancer, its utility in oral squamous cell carcinoma (OSCC) has not been elucidated. In this retrospective multicentre cohort study, we evaluated the association between NLR and outcome of nivolumab treatment in 64 patients with OSCC treated between 2017 and 2020. The objective response and disease control rates were 25.1% and 32.9%, respectively. The rates for complete and partial responses were 15.7% (10/64) and 9.4% (6/64), respectively; stable and progressive disease rates were 7.8% (5/64) and 67.1% (43/64), respectively. Complete and partial responses were classified as responders, and stable and progressive diseases were classified as non-responders. The median (range) pre-treatment NLR among responders was 4.3 (2.8-8.0), which decreased to 4.0 (2.6-6.3) after nivolumab treatment, and the median (range) pre-treatment NLR among non-responders was 5.1 (2.7-7.9), which increased to 6.4 (4.0-14.0) with tumour growth. Moreover, overall survival was significantly worse in the group with a higher post-treatment NLR (≥5) than in the group with a lower NLR (<5). Patients with a post-treatment NLR of ≥6 had worse outcomes for salvage chemotherapy following nivolumab treatment. Thus, post-treatment NLR could be a useful marker for predicting the response to nivolumab treatment or salvage chemotherapy in patients with OSCC.

Liquid-based cytology for differentiating two cases of pemphigus vulgaris from oral squamous cell carcinoma.

Pemphigus vulgaris (PV) is a rare autoimmune disease characterized by blisters on the skin and mucous membrane. Since it often appears in the oral mucosa first, it may be diagnosed by oral mucosal cytology. Although the cytologic finding is characterized by acantholytic cells, that is, Tzanck cells, it is important to distinguish PV from neoplastic lesions of the oral mucosal epithelium, including differentiation from atypical parabasal/basal cells, which appear in squamous cell carcinoma (SCC). In this study, we examined the cellular findings in two cases of PV and a case of well-differentiated SCC with loss of epithelial cell cohesion. The samples were prepared using liquid-based cytology, which showed small round-shaped and deeply stained atypical, orangeophilic keratinocytes not only in SCC but also in PV, which made differentiation between the two difficult. However, Tzanck cells found in PV differ from the deep atypical parabasal/basal cells of SCC, suggesting that the cell outline is indistinct and small protrusions and brush-like structures are observed. This feature of Tzanck cells may be useful in cytological judgment.

Clinical Application of Hyperdry Amniotic Membrane in Cleft Palate Repair.

OBJECTIVE: To examine the safety and efficacy of hyperdry amniotic membrane (HDAM) for wound closure after palatoplasty in cleft palate patients. METHODS: HDAMs were prepared by washing and drying under infrared rays and microwaves at temperatures less than 60°C using a hyperdrying device. A total of 16 cleft palate patients (8 males, 8 females), aged 1 to 3 years (mean age 1 year 9 months), received one-stage pushback palatoplasty. The remaining raw wound after surgery was covered by an HDAM and a plastic cover plate. The cover plate was removed 1 week after surgery and parameters including temperature, feeding, allergic reactions, postoperative bleeding, re-epithelialization, wound dehiscence, and infection were monitored during the follow-up period of 31.2 months. RESULTS: All patients could adequately ingest at 5 days postoperation and after removal of the cover plate. None of the patients had a persistent fever or allergic reactions. Ingestion was feasible immediately in all patients, and no postoperative bleeding was observed during ingestion. No secondary hemorrhages were observed during follow-up. No postoperative wound dehiscence on the midline of the palate was observed. No infections were observed after the removal of the cover plate. No patients suffered from severe scar formation or contracture of the wound in the follow-up period. Hemorrhage, undue epithelialization, and scar contracture did not occur in any patient. The mean evaluation score was 7.75 points. CONCLUSION: HDAM can be used safely and effectively for wound closure following palatoplasty in cleft palate infants. Future studies testing the safety of patient's own amnion for palatoplasty, are required.

Multicenter retrospective study of nivolumab for recurrent/metastatic oral squamous cell carcinoma.

OBJECTIVES: Immunotherapy with nivolumab for patients with recurrent/metastatic oral squamous cell carcinoma has not been evaluated. Here, we aimed to examine the efficacy, safety, and prognostic factors of nivolumab in these patients. MATERIALS AND METHODS: This multicenter retrospective observational study involved patients who received nivolumab between April 2017 and June 2019. The patient characteristics were evaluated for association with progression-free and overall survival. Progression-free and overall survival rates were calculated; parameters that were significant in the univariate analysis were used as explanatory variables. Independent factors for progression-free and overall survival were identified using multivariate analysis. RESULTS: Totally, 143 patients were included. The overall response and disease control rates were 27.3% and 46.2%, respectively. The median, 1- and 2-year progression-free survival rates were 2.7 months, 25.4%, and 19.2%, respectively; those for overall survival were 11.2 months, 47.3%, and 33.6%, respectively. The independent factors affecting progression-free survival were performance status and immune-related adverse event occurrence, whereas those affecting overall survival were performance status, target disease, and number of previous lines of systemic cancer therapy. Eight patients reported grade ≥3 immune-related adverse events. CONCLUSION: Nivolumab was effective for recurrent/metastatic oral squamous cell carcinoma treatment and was well tolerated by patients.

[Comparison between Single and Three Times Pre-operative Administration of Amoxicillin in the Prophylactic Effects for Surgical Site Infections in Japanese Patients with Mandibular Third Molars Extraction].

Although the dosage of oral antibiotics (OA) for the mandibular third molar extraction (MTME) varies among the administration periods according to the current guideline, our previous reports suggested that it might be possible to further shorten the administration period without increasing the incidence of surgical site infection (SSI). In the present study, we retrospectively evaluated the relationship between the incidence of SSI and the administration period of OA in patients who underwent the MTME in our hospital. This retrospective cohort study included 348 patients who underwent the MTME in our dental outpatient clinic from June 2020 to March 2022. The administrated antibiotic was amoxicillin (AMPC) in all patients. Patients were divided into two groups based on the administration period of AMPC single and three times before the surgery. The following information was collected: (1) patient factors (age, gender, body mass index, diagnosis, mandibular third molar status); (2) surgical factors (operation time, presence/absence of wound closure, presence/absence of hemostat, experience of surgeons); (3) relationship between administration period of OA and SSI occurrence; and (4) details of SSI. There were 217 cases in the single group and 131 cases in the three times group. The incidence of SSI was 1.1% (4/348), with 1.4% (3/217) in the single group and 0.8% (1/131) in the three times group; there was no significant difference between the two groups. Our result suggests that single administration of AMPC before the MTME would be sufficient for the prevention of SSI in Japanese patients without risk factors.

Clinicopathologic factors influencing the screening accuracy of oral cytology: A retrospective cohort study.

Cytology is a simple and non-invasive screening method for oral cancer. However, this method is not yet routinely used by clinicians because of its high false negative rate (FNR) and due to lack of sufficient studies examining the factors for high FNRs. The present retrospective study aimed to compare the screening performance of conventional cytology (CC) and liquid-based cytology (LBC) through histological validation, and to elucidate factors inducing false negative screening in oral cytology. Cytological specimens with histological examination and intraoral digital images of the lesion were retrospectively collected between January 2017 and December 2018 for CC and between October 2019 and September 2021 for LBC. Oral cytological screening was conducted based on the oral Bethesda system for oral cytology. Clinical subtypes were re-evaluated using intraoral digital images. The screening accuracy of oral cytology was calculated considering the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting the malignant transformation of oral lesions. No statistically significant difference was noted in the inadequate rate between CC and LBC groups. For CC and LBC, the sensitivities were 60.9 and 59.2%, the specificities were 87.3 and 79.1%, the PPVs were 85.8 and 76.2%, and the NPVs were 63.9 and 63.2%, respectively. Thus, the screening accuracy was similar between methodologies. Among the clinicopathological factors investigated, histological diagnosis and cellularity contributed to false negative results. Homogeneous findings of oral epithelial dysplasia and the superficial growth of carcinoma in situ/squamous cell carcinoma resulted in false negative findings for CC and LBC. Furthermore, LBC samples with a lower cell number (<2,000 squamous cells) exhibited statistically significantly increased FNRs. The present study found that the cytological methods did not affect the inadequate rate and screening accuracy, whereas clinical subtype and cellularity decreased screening accuracy. Therefore, cytological screening and subsequent follow-up should be performed while considering clinical findings and the cellularity of cytology smears.

Unusual generalized tetanus evolving from odontogenic infection: A case report and review of recent literature.

Tetanus is an acute and vaccine-preventable disease caused by anaerobic bacteria, Clostridium tetani. This bacterium can enter the human body via a deep wound, burn injury or medical procedure; however, certain cases also originate from odontogenic infection. In the present study, a tetanus infection associated with dental origin in a 44-year-old man is reported. The case was complicated by lockjaw and difficulty swallowing that worsened over a few days, followed by a generalized spasm. Furthermore, a literature review was performed, in which six reported cases of tetanus, presumed to be of dental or oral origin, were identified between 2011and 2021. General practitioners, especially dentists, should be aware of tetanus associated with odontogenic origin even without a history of an external penetrating wound or other medical procedures:.

Adenosquamous Carcinoma with the Acantholytic Feature in the Oral Cavity: A Case Report and Comprehensive Literature Review.

Adenosquamous carcinoma (ASC) is an aggressive subtype of squamous cell carcinoma (SCC). Due to its poor prognosis, a precise pathological diagnosis of ASC is essential but challenging because its pathological criteria are still unclear. Here, we present a rare case of oral ASC accompanied by acantholytic features. The tumor was raised in the mandibular gingiva and recurred locally approximately 13 months after the initial surgery with cervical lymph node metastasis. Pathological specimens of the primary lesion showed acantholysis in a large area of the SCC. Mucous cells, the characteristic finding indicating glandular differentiation, were imperceptible in the initial surgical specimen but increased in the locally recurrent and metastatic lymph node specimens. In a comprehensive literature review of oral ASC cases, the present case was the only case of ASC with acantholytic features. We reconfirmed that ASC has poor prognoses, such as low 5-year overall survival and disease-free survival, high locoregional recurrence, and high distant metastasis rates. A precise diagnosis of ASC is required for estimating prognosis and undergoing close follow-up, even if the adenocarcinomatous component is limited to a small area in the lesion.

Novel strategy to predict high risk of inferior alveolar nerve injury during extraction of lower third molars based on assessment of computed tomographic images of multiple anatomical features.

Preoperative assessment is essential to prevent inferior alveolar nerve (IAN) injury during surgical extraction of the lower third molar (LM3). Here, we aimed to establish an assessment system to predict IAN injury during surgical extraction of the LM3. We conducted a retrospective cohort study on 115 patients diagnosed as 'high-risk' based on our previous risk assessment method involving three anatomical features of the inferior alveolar canal using computed tomographic (CT) images. We evaluated the occurrence of neurosensory impairment in these high-risk patients, and its association with novel anatomic features based on CT images. Neurosensory impairments were observed in 19 patients (16.5%). The inferior alveolar canal major diameter (p < 0.0001) and lingual bone thickness (p = 0.0039) were significantly associated with the occurrence of neurosensory impairment during LM3 extraction. Receiver operating characteristic curves were used to determine cut-off values of these quantitative factors to specifically predict IAN injury. Preoperative risk assessment with quantitative factors based on anatomical features observed on CT images may facilitate more appropriate surgical planning for patients at a high risk of IAN injury.

RSK-Mediated Non-canonical Activation of EphA2 by Tamoxifen.

The long-term administration of tamoxifen to estrogen receptor α (ERα)-positive breast cancer patients is an established treatment that reduces mortality and recurrence. However, resistance to tamoxifen and an increased risk of endometrial cancer may occur; therefore, the mechanisms by which tamoxifen causes these adverse effects warrant further study. Tamoxifen has been shown to activate mitogen-activated protein kinase (MAPK) in an ERα-independent manner; therefore, we investigated its effects on the MAPK-mediated non-canonical activation of EphA2, a critical event regulating cell migration. Tamoxifen at slightly higher concentrations induced the rapid phosphorylation of EphA2 at Ser-897 via the MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK-ribosomal S6 kinases (RSK) pathway in HeLa cells. In addition, tamoxifen significantly enhanced the migration ability of ERα-negative MDA-MB-231 breast cancer cells in RSK- and EphA2-dependent manners. Phosphorylated EphA2 was internalized and re-localized to the plasma membrane, including lamellipodia, in an RSK-dependent manner. Collectively, the present results provide novel insights into the tumor-promoting activity of tamoxifen.

Sitafloxacin reduces tumor necrosis factor alpha (TNFα) converting enzyme (TACE) phosphorylation and activity to inhibit TNFα release from lipopolysaccharide-stimulated THP-1 cells.

Sepsis is a systemic reaction to an infection and resulting in excessive production of inflammatory cytokines and chemokines. It sometimes results in septic shock. The present study aimed to identify quinolone antibiotics that can reduce tumor necrosis factor alpha (TNFα) production and to elucidate mechanisms underlying inhibition of TNFα production. We identified quinolone antibiotics reduced TNFα production in lipopolysaccharide (LPS)-stimulated THP-1 cells. Sitafloxacin (STFX) is a broad-spectrum antibiotic of the quinolone class. STFX effectively suppressed TNFα production in LPS-stimulated THP-1 cells in a dose-dependent manner and increased extracellular signal-regulated kinase (ERK) phosphorylation. The percentage of intracellular TNFα increased in LPS-stimulated cells with STFX compared with that in LPS-stimulated cells. TNFα converting enzyme (TACE) released TNFα from the cells, and STFX suppressed TACE phosphorylation and activity. To conclude, one of the mechanisms underlying inhibition of TNFα production in LPS-stimulated THP-1 cells treated with STFX is the inhibition of TNFα release from cells via the suppression of TACE phosphorylation and activity. STFX may kill bacteria and suppress inflammation. Therefore, it can be effective for sepsis treatment.

[Neutrophil-to-Lymphocyte Ratio(NLR)as a Predictive Indicator of the Response to Nivolumab in Patients with Oral Squamous Cell Carcinoma].

BACKGROUND: The immune checkpoint inhibitor (ICI) nivolumab has revolutionized the treatment for recurrent or metastatic advanced oral cancer. Because the response rate remains low, the identification of predictive indicators of the response to nivolumab is among the most critical issues. The neutrophil-to-lymphocyte ratio(NLR)is a potential predictive marker of the response to nivolumab in patients with various cancer types. However, the utility of the NLR as a biomarker for predicting the response of oral cancer patients to ICIs is poorly understood. PATIENTS AND METHODS: In this retrospective cohort study, we evaluated the association between NLR and nivolumab treatment outcome in 13 patients diagnosed with recurrent or metastatic oral squamous cell carcinoma(OSCC)treated with nivolumab at the Toyama University Hospital between December 2017 and December 2019. RESULTS: Complete response(CR)and partial response(PR)rates of 38.5%(5/13)and 0% (0/13), respectively, were observed in responders; stable disease(SD)and progressive disease(PD)rates of 7.7%(1/13) and 53.8%(7/13), respectively, were observed in non-responders. After nivolumab treatment, the median NLR among responders decreased to 3.3(3.0-3.9)from 4.1(3.7-4.3)during pre-treatment assessment and increased from 5.6(3.2- 9.2)at pre-treatment to 9.4(5.3-17.9)among non-responders. Moreover, patients with higher NLRs(≥5)in the post- treatment group had a significantly worse overall survival than those with lower NLRs(<5). Specifically, patients with a higher post-treatment NLR(≥10)had significantly worse outcomes for post-nivolumab salvage chemotherapy. CONCLUSION: The NLR could be a useful marker for predicting the treatment response to nivolumab or post-nivolumab salvage chemotherapy in OSCC patients.

Central mucoepidermoid carcinoma of the maxilla developing from a calcifying odontogenic cyst: A rare case report.

Intraosseous mucoepidermoid carcinoma of the jaw is a rare lesion that has been suggested to originate from the odontogenic epithelium. We report an unusual case of central mucoepidermoid carcinoma in an 18-year-old Japanese man with an odontogenic cyst.