PP6 deficiency in mice with KRAS mutation and Trp53 loss promotes early death by PDAC with cachexia-like features.

To examine effects of PP6 gene (Ppp6c) deficiency on pancreatic tumor development, we developed pancreas-specific, tamoxifen-inducible Cre-mediated KP (KRAS(G12D) plus Trp53-deficient) mice (cKP mice) and crossed them with Ppp6cflox / flox mice. cKP mice with the homozygous Ppp6c deletion developed pancreatic tumors, became emaciated and required euthanasia within 150 days of mutation induction, phenotypes that were not seen in heterozygous or wild-type (WT) mice. At 30 days, a comparative analysis of genes commonly altered in homozygous versus WT Ppp6c cKP mice revealed enhanced activation of Erk and NFκB pathways in homozygotes. By 80 days, the number and size of tumors and number of precancerous lesions had significantly increased in the pancreas of Ppp6c homozygous relative to heterozygous or WT cKP mice. Ppp6c-/- tumors were pathologically diagnosed as pancreatic ductal adenocarcinoma (PDAC) undergoing the epithelial-mesenchymal transition (EMT), and cancer cells had invaded surrounding tissues in three out of six cases. Transcriptome and metabolome analyses indicated an enhanced cancer-specific glycolytic metabolism in Ppp6c-deficient cKP mice and the increased expression of inflammatory cytokines. Individual Ppp6c-/- cKP mice showed weight loss, decreased skeletal muscle and adipose tissue, and increased circulating tumor necrosis factor (TNF)-α and IL-6 levels, suggestive of systemic inflammation. Overall, Ppp6c deficiency in the presence of K-ras mutations and Trp53 gene deficiency promoted pancreatic tumorigenesis with generalized cachexia and early death. This study provided the first evidence that Ppp6c suppresses mouse pancreatic carcinogenesis and supports the use of Ppp6c-deficient cKP mice as a model for developing treatments for cachexia associated with pancreatic cancer.

Ppp6c haploinsufficiency accelerates UV-induced BRAF(V600E)-initiated melanomagenesis.

According to TCGA database, mutations in PPP6C (encoding phosphatase PP6) are found in c. 10% of tumors from melanoma patients, in which they coexist with BRAF and NRAS mutations. To assess PP6 function in melanoma carcinogenesis, we generated mice in which we could specifically induce BRAF(V600E) expression and delete Ppp6c in melanocytes. In these mice, melanoma susceptibility following UVB irradiation exhibited the following pattern: Ppp6c semi-deficient (heterozygous) > Ppp6c wild-type > Ppp6c-deficient (homozygous) tumor types. Next-generation sequencing of Ppp6c heterozygous and wild-type melanoma tumors revealed that all harbored Trp53 mutations. However, Ppp6c heterozygous tumors showed a higher Signature 1 (mitotic/mitotic clock) mutation index compared with Ppp6c wild-type tumors, suggesting increased cell division. Analysis of cell lines derived from either Ppp6c heterozygous or wild-type melanoma tissues showed that both formed tumors in nude mice, but Ppp6c heterozygous tumors grew faster compared with those from the wild-type line. Ppp6c knockdown via siRNA in the Ppp6c heterozygous line promoted the accumulation of genomic damage and enhanced apoptosis relative to siRNA controls. We conclude that in the presence of BRAF(V600E) expression and UV-induced Trp53 mutation, Ppp6c haploinsufficiency promotes tumorigenesis.

Loss of protein phosphatase 6 in mouse keratinocytes enhances K-rasG12D -driven tumor promotion.

Here, we address the function of protein phosphatase 6 (PP6) loss on K-ras-initiated tumorigenesis in keratinocytes. To do so, we developed tamoxifen-inducible double mutant (K-rasG12D -expressing and Ppp6c-deficient) mice in which K-rasG12D expression is driven by the cytokeratin 14 (K14) promoter. Doubly-mutant mice showed early onset tumor formation in lips, nipples, external genitalia, anus and palms, and had to be killed by 3 weeks after induction by tamoxifen, while comparably-treated K-rasG12D -expressing mice did not. H&E-staining of lip tumors before euthanasia revealed that all were papillomas, some containing focal squamous cell carcinomas. Immunohistochemical analysis of lips of doubly-mutant vs K-rasG12D mice revealed that cell proliferation and cell size increased approximately 2-fold relative to K-rasG12D -expressing mutants, and epidermal thickness of lip tissue greatly increased relative to that seen in K-rasG12D -only mice. Moreover, AKT phosphorylation increased in K-rasG12D -expressing/Ppp6c-deficient cells, as did phosphorylation of the downstream effectors 4EBP1, S6 and GSK3, suggesting that protein synthesis and survival signals are enhanced in lip tissues of doubly-mutant mice. Finally, increased numbers of K14-positive cells were present in the suprabasal layer of doubly-mutant mice, indicating abnormal keratinocyte differentiation, and γH2AX-positive cells accumulated, indicating perturbed DNA repair. Taken together, Ppp6c deficiency enhances K-rasG12D -dependent tumor promotion.

Multiple Buttresses Reconstruction of Maxilla with Fibular Flap Using Computer-aided Design/Computer-aided Manufacturing after Maxillectomy.

Background: The maxilla comprises horizontal and vertical buttresses, each with specific functions, supporting various organs, such as the eyes, nose, and oral cavity. Notably, they combine to form a three-dimensional structure, which enables the buttresses to provide their inherent support strength. However, reconstructing the maxilla after maxillectomy by assembling new buttresses is challenging. We successfully reconstructed all the buttresses crucial for facial appearance and dental rehabilitation using a vascularized fibular flap. Methods: Four patients underwent maxillary buttress reconstruction with a fibular flap after total or subtotal maxillectomy. We used computer-aided design/computer-aided manufacturing digital technology to osteotomize the fibula into multiple segments and assemble them to reconstruct the maxillary buttresses. Each buttress was assembled based on a preoperative simulation. Results: All patients underwent immediate one-stage maxillary reconstruction. They had good maxillary buttress alignment and acquired good facial appearance, eye position, nasal airway, and prosthetically suitable maxillary alveolus ridge. Conclusions: The combination of computer-aided design/computer-aided manufacturing digital technology and surgical techniques has enabled novel maxillary reconstruction, providing great hope to patients experiencing facial disfigurement and loss of function after maxillectomy.

Preservation of remnant esophagus during total pharyngolaryngectomy in a patient with previous subtotal esophagectomy: a case report.

BACKGROUND: With the improved survival rate of patients with esophageal cancer, secondary cancers, including pharyngolaryngeal cancer, have become a problem. Phanryngolaryngeal cancer surgery often requires esophagogastric anastomosis resection in patients with a previous history of subtotal esophagectomy. Owing to adhesions, especially surrounding the esophagogastric anastomosis, caused by the initial surgery, the second surgery might cause postoperative complications. CASE PRESENTATION: A 65-year-old man was diagnosed with early stage esophageal squamous cell carcinoma and underwent endoscopic mucosal dissection. However, the histopathological depth of the tumor was pT1b, and additional treatment was required. After administration of the neoadjuvant chemotherapy, he underwent thoracoscopic esophagectomy and retrosternum reconstruction via a gastric tube (pT1N3M0 stage III). Eight months after the first surgery, tumor recurrences were observed at the anastomosis and left cervical lymph node. Definitive chemoradiotherapy was performed for the recurrences, and complete response was achieved. Seven months after chemoradiotherapy, he was diagnosed with hypopharyngeal squamous cell carcinoma in the right piriform fossa (cT2N2bM0 stage IVA), and salvage surgery was chosen as treatment. The surgical findings revealed strong adhesion around the remnant esophagus, which was difficult to dissect from surrounding tissue and was associated with a risk of breaking of the anastomosis. However, indocyanine green fluorescence imaging findings indicated sufficient blood flow to preserve the remnant esophagus, including the anastomosis, even after the interruption of blood flow from the proximal side of the esophagus by total pharyngolaryngectomy. Finally, approximately 4 cm of the remnant esophagus was preserved, and the free jejunum reconstruction with cervical vascular anastomosis was performed. Moreover, the patient was discharged without complications on postoperative day 38. After 10 months of the second surgery, a metastatic lymph node was observed in the right neck. Immune checkpoint inhibitors and chemotherapy were administered, and the patient is alive and under treatment 1.5 years after the second surgery. CONCLUSIONS: Blood supply to the remnant cervical esophagus was thought to be from the gastric conduit over the anastomosis and surrounding capillaries. Thus, the preservation of the remnant esophagus can be considered in total pharyngolaryngectomy even after < 2 years of esophagectomy by blood flow evaluation using indocyanine green fluorescence.

Impact of CAD/CAM mandibular reconstruction on chewing and swallowing function after surgery for locally advanced oral cancer: A retrospective study of 50 cases.

OBJECTIVE: Computer-aided design and computer-aided manufacturing (CAD/CAM) techniques are increasingly applied to mandibular reconstruction, but the superiority of this method in oral food intake has not been well established. Considering the extent of mandibular defects, this retrospective study was aimed to clarify the impact of CAD/CAM mandibular reconstruction on chewing and swallowing function after surgery for locally advanced oral cancer. MATERIALS AND METHODS: We performed a retrospective review of 50 patients who had undergone segmental mandibulectomy with free flap reconstruction for locally advanced oral cancer. The patients' Functional Oral Intake Scale scores were measured at 3 months after surgery, and possible contributing factors including CAD/CAM mandibular reconstruction and the extent of mandibular defects for oral food intake were subjected to univariate analysis and multivariate logistic regression analysis. RESULTS: Multivariate logistic regression analysis showed that CAD/CAM mandibular reconstruction was independently associated with good oral intake, whereas both anterior or extensive mandibular resection and glossectomy were also independently associated with poor oral intake after surgery. CONCLUSION: The present study showed the positive impact of CAD/CAM mandibular reconstruction on chewing and swallowing function after surgery for locally advanced oral cancer for the first time.

Ppp6c deficiency accelerates K-rasG12D -induced tongue carcinogenesis.

BACKGROUND: Effective treatments for cancer harboring mutant RAS are lacking. In Drosophila, it was reported that PP6 suppresses tumorigenicity of mutant RAS. However, the information how PP6 regulates oncogenic RAS in mammals is limited. METHODS: We examined the effects of PP6 gene (Ppp6c) deficiency on tongue tumor development in K (K-rasG12D)- and KP (K-rasG12D + Trp53-deficient)-inducible mice. RESULTS: Mice of K and KP genotypes developed squamous cell carcinoma in situ in the tongue approximately 2 weeks after the induction of Ppp6c deficiency and was euthanized due to 20% loss of body weight. Transcriptome analysis revealed significantly different gene expressions between tissues of Ppp6c-deficient tongues and those of Ppp6c wild type, while Trp53 deficiency had a relatively smaller effect. We then analyzed genes commonly altered by Ppp6c deficiency, with or without Trp53 deficiency, and identified a group concentrated in KEGG database pathways defined as 'Pathways in Cancer' and 'Cytokine-cytokine receptor interaction'. We then evaluated signals downstream of oncogenic RAS and those regulated by PP6 substrates and found that in the presence of K-rasG12D, Ppp6c deletion enhanced the activation of the ERK-ELK1-FOS, AKT-4EBP1, and AKT-FOXO-CyclinD1 axes. Ppp6c deletion combined with K-rasG12D also enhanced DNA double-strand break (DSB) accumulation and activated NFκB signaling, upregulating IL-1ß, COX2, and TNF.

Enhanced recovery after surgery program involving preoperative dexamethasone administration for head and neck surgery with free tissue transfer reconstruction: Single-center prospective observational study.

BACKGROUND: There are few reports on Enhanced Recovery After Surgery (ERAS)-based perioperative management following head and neck surgery with free tissue transfer reconstruction (HNS-FTTR). Here, we prospectively evaluated our ERAS program involving preoperative glucocorticoid administration in HNS-FTTR. METHODS: This prospective study included 60 patients who underwent HNS-FTTR at the Miyagi Cancer Center from June 2017 to December 2018. Their treatment plan included receiving perioperative management in accordance with our head and neck ERAS program. Major outcomes of hospitalization periods, early mobilization, early enteral nutrition, and patient satisfaction were assessed, and blood date and vital signs were compared with control patients who underwent HNS-FTTR from January 2014 to September 2016 at our institution before ERAS was implemented. RESULTS: The duration of hospital stay and the duration until completion of the discharge criteria was a median of 25 days and 17 days, respectively. Early mobilization was achieved in 86.0% of the patients at postoperative-day (POD)1 and 96.5% at POD2. Enteral nutrition was started in 80.1% at POD1 and 100% at POD2. Postoperative pain was controlled at mean VAS scores of 1.51-3.13. Clavien-Dindo grade II or higher postoperative complications were evident in 27.6% of the patients. The mean QOR40 score was 179.6 preoperatively, 146.1 at POD3, and 167.8 at POD7. Compared with the control group, there were significantly lower C-reactive protein levels, higher albumin levels, a lower body temperature, a lower neutrophil-to-lymphocyte ratio, less body weight fluctuation, and fewer incidences of decreased blood pressure in the ERAS group. CONCLUSION: Patients who underwent HNS-FTTR with ERAS-based perioperative management achieved early mobilization, early enteral nutrition, favorable pain control, remarkable recovery of patient satisfaction at POD7, and there was evidence of better hemodynamic stability and less inflammatory response compared with control patients.

Diabetes care providers' manual for disaster diabetes care.

To ensure that experiences and lessons learned from the unprecedented 2011 Great East Japan Earthquake are used to improve future disaster planning, the Japan Diabetes Society (JDS) launched the "Research and Survey Committee for Establishing Disaster Diabetes Care Systems Based on Relevant Findings from the Great East Japan Earthquake" under the supervision of the Chairman of the JDS. The Committee conducted a questionnaire survey among patients with diabetes, physicians, disaster medical assistance teams (DMATs), nurses, pharmacists, and nutritionists in disaster areas about the events they saw happening, the situations they found difficult to handle, and the needs that they felt required to be met during the 2011 Great East Japan Earthquake. A total of 3,481 completed questionnaires were received. Based on these and other experiences and lessons reported following the 2011 Great East Japan Earthquake and the 2004 Niigata-Chuetsu Earthquakes, the current "Manual for Disaster Diabetes Care" has been developed by the members of the Committee and other invited authors from relevant specialties. To our knowledge, the current Manual is the world's first to focus on emergency diabetes care, with this digest English version translated from the Japanese original. It is sincerely hoped that patients with diabetes and healthcare providers around the world will find this manual helpful in promoting disaster preparedness and implementing disaster relief.

Diabetes Care Providers' Manual for Disaster Diabetes Care.

To ensure that experiences and lessons learned from the unprecedented 2011 Great East Japan Earthquake are used to improve future disaster planning, the Japan Diabetes Society (JDS) launched the "Research and Survey Committee for Establishing Disaster Diabetes Care Systems Based on Relevant Findings from the Great East Japan Earthquake" under the supervision of the Chairman of the JDS. The Committee conducted a questionnaire survey among patients with diabetes, physicians, disaster medical assistance teams (DMATs), nurses, pharmacists, and nutritionists in disaster areas about the events they saw happening, the situations they found difficult to handle, and the needs that they felt required to be met during the 2011 Great East Japan Earthquake. A total of 3,481 completed questionnaires were received. Based on these and other experiences and lessons reported following the 2011 Great East Japan Earthquake and the 2004 Niigata-Chuetsu Earthquakes, the current "Manual for Disaster Diabetes Care" has been developed by the members of the Committee and other invited authors from relevant specialties. To our knowledge, the current Manual is the world's first to focus on emergency diabetes care, with this digest English version translated from the Japanese original. It is sincerely hoped that patients with diabetes and healthcare providers around the world will find this manual helpful in promoting disaster preparedness and implementing disaster relief.

Laryngeal function-preserving operation for T4a laryngeal cancer with vocal cord paralysis - A case report.

For locally advanced laryngeal cancers, the standard treatment of choice is chemoradiotherapy if organ function needs to be conserved. Surgical treatment with larynx preservation is conducted only for limited cases. For locally advanced laryngeal cancers such as those with vocal cord fixation and/or cricoid cartilage destruction, there is no apparent standardized organ-preserving surgery keeping the essential laryngeal functions, viz. the airway, deglutition and articulation, uncompromized. Recently, our surgical team saw a patient with T4a advanced laryngeal cancer with vocal cord fixation who aspired to maintain his laryngeal function. Driven by his eagerness, we contrived novel techniques for laryngeal function preservation and performed a two-staged operation. In the first stage, extended vertical partial laryngectomy was conducted including resection of the affected thyroid, arytenoid, and cricoid cartilages, followed by local closure of the hypopharynx. Additionally, laryngeal suspension surgery and cricopharyngeal myotomy were performed in addition to suturing the epiglottis with the intact arytenoid cartilage to enhance swallowing function. In the second stage, airway reconstruction was performed using a local skin flap. As of 10 months after operation, there has been no tumor recurrence, and the reconstructed larynx has been working satisfactorily. In this report we describe an innovative operation that was especially contrived for laryngeal function preservation.

A Novel Laryngeal Preservation Technique following Total Glossectomy with Hyoid Bone Resection.

Despite the recent progress of chemotherapy and sophisticated radiotherapy, surgery still remains the most reliable treatment for advanced tongue cancers in terms of survival. The major disadvantage of this treatment is that it should sacrifice the quality of patients' life. When the tongue cancer is so advanced as to involve the hyoid bone, which is considered a functional part of the larynx, radical operation needs to resect both the entire tongue and the larynx and the hyoid bone en bloc to prevent aspiration pneumonia. As a result of total laryngectomy, the patients will suffer significant disabilities: aphonia and the loss of deglutition that limits the oral intake to only liquid or pasty food. With this clinical background, we have been contriving to overcome these significant surgical shortcomings by conducting larynx-preserving operation. In this case report, we present our newly devised surgical method which consists of free-flap transfer with a combination of laryngeal suspension and a novel reconstructive technique, that is, epiglottis suspension, which enabled favorable swallowing function without aspiration and allowed a sufficiently wide airway for breathing. The operation worked quite successfully for the patient's quality of life. We believe this novel surgical method would serve as a larynx-preservation treatment for locally advanced tongue cancers with hyoid bone invasion.

Enhanced Recovery After Surgery program with dexamethasone administration for major head and neck surgery with free tissue transfer reconstruction: initial institutional experience.

OBJECTIVES: Enhanced Recovery After Surgery (ERAS) protocols promote recovery after various invasive surgeries. Likewise, preoperative glucocorticoid administration can reduce complications after some surgeries. However, the effects of ERAS protocols and glucocorticoid administration in patients undergoing major surgery for head and neck cancer have not been well described. The aim of this study was to evaluate the effect of an ERAS protocol with preoperative glucocorticoid administration in major surgery for head and neck cancer. METHODS: This retrospective study included 28 patients who underwent major head and neck surgery with free tissue transfer reconstruction at our institution from September 2016 to May 2017, after implementation of an ERAS protocol with preoperative glucocorticoid administration. Outcomes in that group were compared with those in a control group that underwent surgery from January 2015 to September 2016, before implementation of the protocol. RESULTS: Analysis revealed significantly less body weight fluctuation, lower C-reactive protein levels, higher albumin levels, and lower body temperature in the ERAS group than in the control group postoperatively. CONCLUSIONS: Patients undergoing major surgery for head and neck cancer who were treated with the ERAS protocol and preoperative glucocorticoid administration had evidence of better hemodynamic stability and less inflammatory response than control patients.

PKM1 Confers Metabolic Advantages and Promotes Cell-Autonomous Tumor Cell Growth.

Expression of PKM2, which diverts glucose-derived carbon from catabolic to biosynthetic pathways, is a hallmark of cancer. However, PKM2 function in tumorigenesis remains controversial. Here, we show that, when expressed rather than PKM2, the PKM isoform PKM1 exhibits a tumor-promoting function in KRASG12D-induced or carcinogen-initiated mouse models or in some human cancers. Analysis of Pkm mutant mouse lines expressing specific PKM isoforms established that PKM1 boosts tumor growth cell intrinsically. PKM1 activated glucose catabolism and stimulated autophagy/mitophagy, favoring malignancy. Importantly, we observed that pulmonary neuroendocrine tumors (NETs), including small-cell lung cancer (SCLC), express PKM1, and that PKM1 expression is required for SCLC cell proliferation. Our findings provide a rationale for targeting PKM1 therapeutically in certain cancer subtypes, including pulmonary NETs.

A Novel Funnel-Shaped Flap for Reconstruction Surgery after Total Laryngopharyngectomy with Total Glossectomy.

Reconstruction following total laryngopharyngectomy with total glossectomy (TLPTG) is challenging. To reconstruct this extended range of mucosal defect, it is necessary to overcome the remarkable discrepancy of apertures of oral and esophageal sides. We report a case of reconstruction surgery for total laryngopharyngectomy with total glossectomy with a funnel-shaped rectus abdominis musclocutaneous flap. The patient recovered without major complications and could keep a relatively good swallowing function. We believe this simple method should contribute to cases with complicated ablation.

Late-onset dysphagia caused by severe spastic peristalsis of a free jejunal graft in a case of hypopharyngeal cancer.

Free jejunal transfer is the main technique used for reconstructing a circumferential defect caused by total pharyngo-laryngo-cervical-esophagectomy in certain cancer cases. We report a rare case of severe late-onset dysphagia caused by autonomous spastic peristalsis, which led to complete obstruction of the free jejunal route. A 70-year-old man underwent treatment for hypopharyngeal cancer involving total pharyngolaryngectomy with free jejunal transfer. After uneventful peri- and postoperative recovery, he developed sudden-onset severe dysphagia 22 months later. Gastrografin fluoroscopy revealed abnormal peristalsis and contraction of the transferred jejunum, leading to complete obstruction. Nutritional treatment, application of depressants of peristalsis, and xylocaine injection into the outer space of the jejunal mucosa all failed to alleviate the dysphagia. Surgical treatment involving a longitudinal incision of the jejunal graft, and interposing a cutaneous flap, as a fixed wall, between the incised jejunal margins to prevent obstruction was performed. After further reconstructive surgery involving using a pectoralis major musculocutaneous flap and a split-thickness skin graft to close a refractory jejunum-skin fistula, the dysphagia was permanently alleviated. To our knowledge, this is the first report of severe dysphagia caused by peristalsis of a free jejunal graft.

Loss of protein phosphatase 6 in mouse keratinocytes increases susceptibility to ultraviolet-B-induced carcinogenesis.

We previously reported that deficiency in the gene encoding the catalytic subunit of protein phosphatase 6 (Ppp6c) predisposes mouse skin tissue to papilloma formation initiated by DMBA. Here, we demonstrate that Ppp6c loss acts as a tumor promoter in UVB-induced squamous cell carcinogenesis. Following UVB irradiation, mice with Ppp6c-deficient keratinocytes showed a higher incidence of skin squamous cell carcinoma than did control mice. Time course experiments showed that following UVB irradiation, Ppp6c-deficient keratinocytes upregulated expression of p53, PUMA, BAX, and cleaved caspase-3 proteins. UVB-induced tumors in Ppp6c-deficient keratinocytes exhibited a high frequency of both p53- and γH2AX-positive cells, suggestive of DNA damage. Epidemiological and molecular data strongly suggest that UVB from sunlight induces p53 gene mutations in keratinocytes and is the primary causative agent of human skin cancers. Our analysis suggests that PP6 deficiency underlies molecular events that drive outgrowth of initiated keratinocytes harboring UVB-induced mutated p53. Understanding PP6 function in preventing UV-induced tumorigenesis could suggest strategies to prevent and treat this condition.

One-stage reconstruction of a tracheal defect with a free radial forearm flap and free costal cartilage grafts.

Reconstructing the trachea is challenging because of its multilayer structure and airway function; multiple procedures are often required. We report a case of one-stage reconstruction for a tracheal defect. The surgery was performed with a free radial forearm flap and free costal cartilage grafts. Air leakage occurred postoperatively but healed without additional surgery. The reconstructed trachea has retained its shape, diameter and airway function for 14 months despite the patient's history of radiotherapy. This one-stage procedure with well-vascularised tissue was successfully used to reconstruct a stable, well-functioning trachea.