Cell Cycle Regulation via the p53, PTEN, and BRCA1 Tumor Suppressors

Multiple cell cycle regulatory proteins play an important role in oncogenesis. Cancer cells may arise from dysregulation of various genes involved in the regulation of the cell cycle. In addition, cyclin-dependent kinase inhibitors are regarded as key regulators for cancer cell proliferation. Accordingly, permission of impaired cells by cell cycle checkpoints suppresses carcinogenesis. P53, a multifunctional protein, controls G1-S transition, which is the strongest tumor suppressor involved in the regulation of cell cycle. The p53 is stimulated by cellular stress like oxidative stress. Upon activation, p53 leads to cell cycle arrest and promotes DNA repair; otherwise, it induces apoptosis. One of the target effectors of p53 is the phosphatase and tensin homolog deleted on chromosome 10 (PTEN). The tumor suppressor PTEN is a dual-specificity phosphatase which has protein phosphatase activity and lipid phosphatase activity that antagonizes PI3K/AKT activity. The PI3K/AKT cell survival pathway is shown as regulator of cell proliferation. The p53 cooperates with PTEN and might be an essential barrier in development of cancers. BRCA1 plays an important role in DNA repair processes related to maintenance of genomic integrity and control of cell growth. The inactivation of these tumor suppressor proteins confers a growth advantage of cancer. This chapter summarizes the function of several tumor suppressors in the cell cycle regulation

Prolonged Radiation Damage in Rat Colon and Urokinase Expression in Epithelium

Although radiation therapy plays important role in the treatment of gynecological tumors, it may cause radiation injury as a late effect. Several recent reports show that urokinase such as urokinase type plasminogen activator (uPA) contributes to the repair of ulcerative lesions of the colon epithelium. We studied radiation induced enterocolitis using rat animal models. Seventy-two female Wistar rats were irradiated by a single fraction dose of 36Gy at laparotomy. Histological changes and activity of urokinase system were investigated after irradiation. Ulcers were observed in irradiated field in 12 of 19 animals (63%) even at 60th week after irradiation. Urokinase expressions were observed in the margins of active ulcer. Urokinase was thought to play important role in exacerbation of ulcer formation. Expression of uPA was also observed in submucosal glands. Ischaemic changes were not observed in irradiated colon despite sclerosing vasculitis. It is suggested that uPA played reciprocal roles in radiation induced enterocolitis: healing and aggravation of ulcer

Acquistion of Motion Intelligence Using Dynamical Coupling -ReaIization of Travelling by Arm 's Motion of Mobile Manipulator without Driving System -

In this research， we propose a concept of motion intelligence using a mobile manipulator which does not possess driving power. The motion intelligence is defined here as that the mobile manipulator can find by itself a way to use its dynamical coupling for a desired motion，that is here， travel1ing motion. We propose a strategy that a machine can maximize the effect of the dynamical coupling using static nonlinear friction between wheels and floor. The method proposed in this paper is composed of a way to give a mounted manipulator a sample motion using Fourier Series and an evaluation function used in Genetic Algorithm as a fitness function. We confirmed by real experiments that the mobile manipulator could find effective and best motion of l-link mounted manipulator which makes i

Real-world outcomes of nivolumab plus ipilimumab and pembrolizumab with platinum-based chemotherapy in advanced non-small cell lung cancer: a multicenter retrospective comparative study

The version of record of this article, first published in Cancer Immunology, Immunotherapy, is available online at Publisher’s website: https://doi.org/10.1007/s00262-023-03583-4Introduction: Nivolumab plus ipilimumab with chemotherapy (NICT) and pembrolizumab with chemotherapy (PCT) are commonly used in patients with advanced non-small cell lung cancer (NSCLC). Compared with immune checkpoint inhibitor (ICI) monotherapy, ICI combination therapy can increase immune-related toxicity instead of prolonging survival. This study aimed to compare the efficacy and safety of NICT and PCT to decide on the favorable treatment. Methods: We conducted a multi-center retrospective cohort study on patients who underwent NICT or PCT between December 2018 and May 2022. Propensity score matching (PSM) was performed with the variables age, sex, smoking status, performance status, stage, histology, and programmed cell death ligand-1 (PD-L1). The Kaplan–Meier method was used to compare survival for the matched patients. Results: Six hundred consecutive patients were included. After PSM, 81 and 162 patients were enrolled in the NICT and PCT groups, respectively. The baseline characteristics were well-balanced. The median progression-free survival was equivalent (11.6 vs. 7.4 months; P = 0.582); however, the median overall survival (OS) was significantly longer in the NICT group than in the PCT group (26.0 vs. 16.8 months; P = 0.005). Furthermore, OS was better in PD-L1-negative patients who underwent NICT than in those who underwent PCT (26.0 vs. 16.8 months; P = 0.045). Safety profiles did not differ significantly in terms of severe adverse event and treatment-related death rates (P = 0.560, and 0.722, respectively). Conclusions: Real-world data suggests that NICT could be a favorable treatment option compared with PCT for patients with advanced NSCLC. Further follow-up is needed to determine the long-term prognostic benefit

Background Coloration of Squamous Epithelium in Esophago-Pharyngeal Squamous Cell Carcinoma: What Causes the Color Change?

Objectives: This study aims to clarify the cause of background coloration in the epithelia between each dilated intra papillary capillary loop in esophago-pharyngeal squamous cell carcinoma. Design: This is a single center retrospective study including 124 patients with 160 lesions who underwent esophagogastroduodenoscopy in Nagasaki University Hospital from September 2007 to March 2012; a detailed comparison between endoscopic images and pathology was performed. Immunohistological assessment using anti-human hemoglobin antibody (anti-Hb Ab) was performed to verify the presence of hemoglobin (Hb) component in the cancer cells. Real-time polymerase chain reaction (RT-PCR) and in situ hybridization (ISH) on Hb-β mRNA were performed to assess the production of Hb component within the cancer cells. Results: A strong positivity for anti-Hb Ab was observed in the squamous cell carcinoma area, whereas non-cancerous mucosa showed no immunopositivity for Hb. The concordance rate between anti-Hb Ab immunoreactivity and the presence of BC was as high as 80.9%. The amount of Hb-β mRNA expression was three times higher in cancer tissues compared with the surrounding non-cancerous mucosa. ISH images showed that the expression exclusively occurred in cancer cells, indicating that Hb is probably produced within cancer cells. Conclusions: The background coloration observed is partly due to an extravascular component of Hb. RT-PCR and ISH analyses indicate that Hb is produced within cancer cells

Improvement of endocytoscopic findings after per oral endoscopic myotomy (POEM) in esophageal achalasia; does POEM reduce the risk of developing esophageal carcinoma? Per oral endoscopic myotomy, endocytoscopy and carcinogenesis

Background: Per oral endoscopic myotomy (POEM) has been reported to be a new therapeutic option for esophageal achalasia. The possibility that POEM could reduce the risk of developing esophageal squamous cell carcinoma was evaluated.Methods: This was a single-centre, retrospective study. Fifteen consecutive patients with esophageal achalasia who underwent POEM in our institution between August 2010 and January 2012 were enrolled. Ultra-high magnification with endocytoscopy was performed, and both histopathological and immunohistochemical evaluations for Ki-67 and p53 were assessed before and 3 months after POEM.Results: POEM was successfully performed and effectively released the dysphagia symptom in all patients without severe complications. Subjective symptoms (mean Ekcardt score, before 7.4 vs. after 0.5, p<0.05) and manometric pressure studies (mean lower esophageal sphincter pressure), before 82.7 vs. after 22.9 mmHg, p<0.05) showed substantial improvement following POEM. The average numbers of esophageal epithelial nuclei before and after POEM on endocytoscopic images were 128.0 and 78.0, respectively (p<0.05). The mean Ki-67-positive ratio was 26.0 (median 25.4, range, 10.3-33.2) before and 20.7 (median 20.0, 13.1-29.9; p=0.07) after POEM, and the mean p53-positive ratio was 2.35 (median 2.61, 0.32-4.23) before and 0.97 (median 1.49, 0.32-1.56; p<0.05) after POEM. A significant positive correlation was seen between the number of nuclei and the Ki-67-positive ratio (p<0.05).Conclusions: POEM appears to be an effective and less invasive treatment of choice against achalasia and may reduce the risk of esophageal carcinogenesis. Endocytoscopy can be useful for the assessment of esophageal cellular proliferation

Cryptotanshinone suppresses tumorigenesis by inhibiting lipogenesis and promoting reactive oxygen species production in KRAS‑activated pancreatic cancer cells

Pyruvate dehydrogenase kinase 4 (PDK4) is an important regulator of energy metabolism. Previously, knockdown of PDK4 by specific small interfering RNAs (siRNAs) have been shown to suppress the expression of Κirsten rat sarcoma viral oncogene homolog (KRAS) and the growth of lung and colorectal cancer cells, indicating that PDK4 is an attractive target of cancer therapy by altering energy metabolism. The authors previously reported that a novel small molecule, cryptotanshinone (CPT), which inhibits PDK4 activity, suppresses the in vitro three‑dimensional (3D)‑spheroid formation and in vivo tumorigenesis of KRAS‑activated human pancreatic and colorectal cancer cells. The present study investigated the molecular mechanism of CPT‑induced tumor suppression via alteration of glutamine and lipid metabolism in human pancreatic and colon cancer cell lines with mutant and wild‑type KRAS. The antitumor effect of CPT was more pronounced in the cancer cells containing mutant KRAS compared with those containing wild‑type KRAS. CPT treatment decreased glutamine and lipid metabolism, affected redox regulation and increased reactive oxygen species (ROS) production in the pancreatic cancer cell line MIAPaCa‑2 containing mutant KRAS. Suppression of activated KRAS by specific siRNAs decreased 3D‑spheroid formation, the expression of acetyl‑CoA carboxylase 1 and fatty acid synthase (FASN) and lipid synthesis. The suppression also reduced glutathione‑SH/glutathione disulfide and increased the production of ROS. Knockdown of FASN suppressed lipid synthesis in MIAPaCa‑2 cells, partially promoted ROS production and mildly suppressed 3D‑spheroid formation. These results indicated that CPT reduced tumorigenesis by inhibiting lipid metabolism and promoting ROS production in a mutant KRAS‑dependent manner. This PDK4 inhibitor could serve as a novel therapeutic drug for KRAS‑driven intractable cancers via alteration of cell metabolism