Adhesion and shrinkage transform the rounded pupal horn into an angular adult horn in Japanese rhinoceros beetle.

Clarifying the mechanisms underlying shape alterations during insect metamorphosis is important for understanding exoskeletal morphogenesis. The large horn of the Japanese rhinoceros beetle Trypoxylus dichotomus is the result of drastic metamorphosis, wherein it appears as a rounded shape during pupation and then undergoes remodeling into an angular adult shape. However, the mechanical mechanisms underlying this remodeling process remain unknown. In this study, we investigated the remodeling mechanisms of the Japanese rhinoceros beetle horn by developing a physical simulation. We identified three factors contributing to remodeling by biological experiments - ventral adhesion, uneven shrinkage, and volume reduction - which were demonstrated to be crucial for transformation using a physical simulation. Furthermore, we corroborated our findings by applying the simulation to the mandibular remodeling of stag beetles. These results indicated that physical simulation applies to pupal remodeling in other beetles, and the morphogenic mechanism could explain various exoskeletal shapes.

Position of meristems and the angles of the cell division plane regulate the uniqueness of lateral organ shape.

Leaf meristem is a cell proliferative zone present in the lateral organ primordia. In this study, we examined how cell proliferative zones in primordia of planar floral organs and polar auxin transport inhibitor (PATI)-treated leaf organs differ from those of non-treated foliage leaves of Arabidopsis thaliana, with a focus on the accumulation pattern of ANGUSTIFOLIA3 (AN3) protein, a key element for leaf meristem positioning. We found that PATI-induced leaf shape changes were correlated with cell division angle but not with meristem positioning/size or AN3 localisation. In contrast, different shapes between sepals and petals compared with foliage leaves were associated with both altered meristem position, due to altered AN3 expression patterns, and different distributions of cell division angles. A numerical simulation showed that meristem position majorly affected the final shape but biased cell division angles had a minor effect. Taken together, these results suggest that the unique shapes of different lateral organs depend on the position of the meristem in the case of floral organs and cell division angles in the case of leaf organs with different auxin flow.

Natural history of hearing and tumor growth in vestibular schwannoma in neurofibromatosis type 2-related schwannomatosis.

OBJECTIVES: To determine the natural history of hearing loss and tumor volume in patients with untreated neurofibromatosis type 2 (NF2)-related schwannomatosis. Moreover, we statistically examined the factors affecting hearing prognosis. METHODS: This retrospective cohort study was conducted on 37 ears of 24 patients with NF2-related vestibular schwannomatosis followed up without treatment for more than 1 year. We obtained detailed chronological changes in the PTA and tumor volume in each case over time, and the rate of change per year was obtained. Multivariate analysis was also conducted to investigate factors associated with changes in hearing. RESULTS: The average follow-up period was approximately 9 years, and hearing deteriorated at an average rate of approximately 4 dB/year. The rate of maintaining effective hearing decreased from 30 ears (81%) at the first visit to 19 ears (51%) at the final follow-up. The average rate of change in tumor growth for volume was approximately 686.0 mm3/year. This study revealed that most patients with NF2 experienced deterioration in hearing acuity and tumor growth during the natural course. A correlation was observed between an increase in tumor volume and hearing loss (r = 0.686; p < 0.001). CONCLUSIONS: Although the hearing preservation rate in NF2 cases is poor with the current treatment methods, many cases exist in which hearing acuity deteriorates, even during the natural course. Patients with an increased tumor volume during the follow-up period were more likely to experience hearing deterioration. Trial registration number 20140242 (date of registration: 27 October 2014).

Cell-center-based model for simulating three-dimensional monolayer tissue deformation.

The shape of the epithelial monolayer can be depicted as a curved tissue in three-dimensional (3D) space, where individual cells are tightly adhered to one another. The 3D morphogenesis of these tissues is governed by cell dynamics, and a variety of mathematical modeling and simulation studies have been conducted to investigate this process. One promising approach is the cell-center model, which can account for the discreteness of cells. The cell nucleus, which is considered to correspond to the cell center, can be observed experimentally. However, there has been a shortage of cell-center models specifically tailored for simulating 3D monolayer tissue deformation. In this study, we developed a mathematical model based on the cell-center model to simulate 3D monolayer tissue deformation. Our model was confirmed by simulating the in-plane deformation, out-of-plane deformation, and invagination due to apical constriction.

Unveiling the role of differential growth in 3D morphogenesis: An inference method to analyze area expansion rate distribution in biological systems.

The three-dimensional (3D) morphologies of many organs in organisms, such as the curved shapes of leaves and flowers, the branching structure of lungs, and the exoskeletal shape of insects, are formed through surface growth. Although differential growth, a mode of surface growth, has been qualitatively identified as 3D morphogenesis, a quantitative understanding of the mechanical contribution of differential growth is lacking. To address this, we developed a quantitative inference method to analyze the distribution of the area expansion rate, which governs the growth of surfaces into 3D morphology. To validate the accuracy of our method, we tested it on a basic 3D morphology that allowed for the theoretical derivation of the area expansion rate distribution, and then assessed the difference between the predicted outcome and the theoretical solution. We also applied this method to complex 3D shapes and evaluated its accuracy through numerical experiments. The findings of the study revealed a linear decrease in error on a log-log scale with an increase in the number of meshes in both evaluations. This affirmed the reliability of the predictions for meshes that are sufficiently refined. Moreover, we employed our methodology to analyze the developmental process of the Japanese rhinoceros beetle Trypoxylus dichotomus, which is characterized by differential growth regulating 3D morphogenesis. The results indicated a notably high rate of area expansion on the left and right edges of the horn primordium, which is consistent with the experimental evidence of a higher rate of cell division in these regions. Hence, these findings confirm the efficacy of the proposed method in analyzing biological systems.

Three semi-selective media for Pseudomonas syringae pv. maculicola and P. cannabina pv. alisalensis.

Three semi-selective media, DTarTA, SPbc, and SPamt, were developed and tested to isolate Pseudomonas syringae pv. maculicola (Psm) and P. cannabina pv. alisalensis (Pca) from Raphanus sativus seeds. DTarTA contained D-tartaric acid as a carbon source and potassium tellurite, ampicillin sodium, and methyl violet as antibiotics. DTarTA suppressed growth in 19 of the 24 pathovars from the P. syringae complex, whereas Psm and Pca grew and formed gray to black colonies. SPamt contained sucrose and peptone as nutrient sources and was supplemented with bromothymol blue and the same antibiotics present in DTarTA and Psm and Pca formed yellowish to dark brown colonies on the SPamt medium. SPbc contained sucrose and peptone and was supplemented with cephalexin and boric acid as antibiotics and Psm and Pca formed semi-translucent to white colonies on the SPbc medium. SPamt and SPbc suppressed the growth of several plant-associated bacteria (except the P. syringae complex). The growth of saprophytic bacteria in seeds on the different media was compared with that on King's B medium, using five types of commercially available Raphanus sativus seeds. The suppression rate of DTarTA was 85-99% and was lower for seeds with more saprophytic bacteria. The suppression rates of SPamt and SPbc were 90-99%. In detection tests using 10,000 seed samples mixed with Pca or Psm-contaminated seeds, it was possible to selectively isolate Psm and Pca using SPamt and SPbc, even when the colony numbers of the target bacterium constituted less than 10% of the total colonies. KEY POINTS: • Bacterial leaf spot and blight pathogens were selectively isolated from seeds. • DTarTA medium distinguishes these pathogens from P. syringae complex pathovars. • SPamp and SPbc media have different selectivity for plant-associated bacteria.

Elasticity-based boosting of neuroepithelial nucleokinesis via indirect energy transfer from mother to daughter.

Neural progenitor cells (NPCs), which are apicobasally elongated and densely packed in the developing brain, systematically move their nuclei/somata in a cell cycle-dependent manner, called interkinetic nuclear migration (IKNM): apical during G2 and basal during G1. Although intracellular molecular mechanisms of individual IKNM have been explored, how heterogeneous IKNMs are collectively coordinated is unknown. Our quantitative cell-biological and in silico analyses revealed that tissue elasticity mechanically assists an initial step of basalward IKNM. When the soma of an M-phase progenitor cell rounds up using actomyosin within the subapical space, a microzone within 10 µm from the surface, which is compressed and elastic because of the apical surface's contractility, laterally pushes the densely neighboring processes of non-M-phase cells. The pressed processes then recoil centripetally and basally to propel the nuclei/somata of the progenitor's daughter cells. Thus, indirect neighbor-assisted transfer of mechanical energy from mother to daughter helps efficient brain development.

Primers for specific detection and identification of Pseudomonas syringae pv. maculicola and P. cannabina pv. alisalensis.

Bacterial leaf spot and bacterial leaf blight are global threats to the cultivation of cruciferous vegetables, and it is necessary to develop methods to easily detect, identify, and distinguish the causative pathogens Pseudomonas syringae pv. maculicola (Psm) and P. cannabina pv. alisalensis (Pca). Here, we used the sequence specificity of the exchangeable effector loci flanking the hrp gene cluster to design primers that can help detect and discriminate between Psm and Pca. Primers common to both bacteria (hrpK_fw1 and hrpK_fw2) were designed within hrpK at the end of the hrp gene cluster. Psm-specific primers (MAC_rv1 and MAC_rv2) were designed in hopPtoB1 and Pca-specific primers (ALS_rv1 and ALS_rv2) were designed in hopX1 adjacent to hrpK. PCR using hrpK_fw1 and MAC_rv1 or hrpK_fw2 and MAC_rv2 amplified DNA fragments of only Psm, P. syringae pv. tomato (causal agent of tomato bacterial speck), and P. syringae pv. spinaciae (causal agent of spinach bacterial leaf spot), among 76 strains of phytopathogenic bacteria. PCR using hrpK_fw1 and ALS_rv1 or hrpK_2 and ALS_rv2 amplified DNA fragments of only Pca. Multiplex PCR with these primers could easily distinguish Psm and Pca from bacterial colonies isolated on growth media and detect the pathogen in symptomatic leaves. Multiplex nested PCR with the primers detected contamination in one Psm- and/or one Pca-infected seeds in 1000 seeds. These results suggest that these PCR primers could help detect and discriminate Psm and Pca. KEY POINTS: • We investigated Pseudomonas syringae pv. maculicola and P. cannabina pv. alisalensis. • Novel primers common to both bacteria were designed following genome comparison. • Multiplex PCR with new primers could discriminate Psm and Pca.

Detection and identification of Xanthomonas campestris pv. campestris and pv. raphani by multiplex polymerase chain reaction using specific primers.

Black rot and bacterial spots threaten the cultivation of cruciferous vegetables worldwide, and the development of a method that can easily detect, identify, and distinguish their respective pathogens Xanthomonas campestris pv. campestris (Xcc) and X. campestris pv. raphani (Xcr) is required. Multiple whole-genome sequences of Xcc and Xcr were aligned to identify specific regions and subsequently design gene markers. A region present in Xcr, but absent in Xcc, was detected, which was approximately 11.5 kbp in length, sandwiched between the serine protease homolog (SPH) and nicotinate phosphoribosyltransferase gene (pncB). It contained putative cellulose synthesis-related genes, whereas Xcc only had a modified cellulose synthase gene. Designed primers were pncB_fw1 and pncB_fw2 (from the pncB gene), Xcc_rv1 and Xcc_rv2 (from the modified cellulose synthesis gene), and Xcr_rv1 and Xcr_rv2 (from the putative first and second open reading frames of the gene cluster). PCR using pncB_fw1 and Xcc_rv1, or pncB_fw2 and Xcc_rv2, amplified DNA fragments only in Xcc and X. campestris pv. incanae (Xci). Xci is the causal agent of black rot of garden stock and closely related to Xcc. PCR using pncB_fw1 and Xcr_rv1, or pncB_2 and Xcr_rv2, amplified DNA fragments only in Xcr. Multiplex PCR analysis easily distinguished Xcc and Xcr from bacterial colonies isolated on growth media and detected the pathogen in symptomatic leaves. Multiplex nested PCR detected the contamination of one seed with Xcc and/or Xcr infection from 1000 seeds. Therefore, the PCR primers designed in this study therefore helped detect and discriminate between Xcc and Xcr. KEY POINTS: • Xanthomonas campestris pv. campestris (Xcc) and pv. raphani (Xcr) were investigated. • Novel primers were designed following whole-genome comparison analyses. • Multiplex PCR with new primers distinguished Xcc and Xcr simultaneously.

PCP-dependent transcellular regulation of actomyosin oscillation facilitates convergent extension of vertebrate tissue.

Oscillatory flows of actomyosin play a key role in the migration of single cells in culture and in collective cell movements in Drosophila embryos. In vertebrate embryos undergoing convergent extension (CE), the Planar Cell Polarity (PCP) pathway drives the elongation of the body axis and shapes the central nervous system, and mutations of the PCP genes predispose humans to various malformations including neural tube defects. However, the spatiotemporal patterns of oscillatory actomyosin contractions during vertebrate CE and how they are controlled by the PCP signaling remain unknown. Here, we address these outstanding issues using a combination of in vivo imaging and mathematical modeling. We find that effective execution of CE requires alternative oscillations of cortical actomyosin across cell membranes of neighboring cells within an optimal frequency range. Intriguingly, temporal and spatial clustering of the core PCP protein Prickle 2 (Pk2) is correlated to submembranous accumulations of F-actin, and depletion of Pk2 perturbs the oscillation of actomyosin contractions. These findings shed light on the significance of temporal regulation of actomyosin contraction by the PCP pathway during CE, in addition to its well-studied spatial aspects.

Collective and contractile filament motions in the myosin motility assay.

Cells require mechanical forces for their physiological functions. The forces are generated mainly from molecular interactions between actin filaments, cross-linking proteins, and myosin motors in the actin cytoskeleton. To better understand the molecular interactions, many studies employed myosin motility assays with actin filaments propelled by myosin heads fixed on a surface. Various interesting behaviors of actin filaments have been observed in the motility assay experiments. Despite the popularity of the motility assays, there were only a few computational models designed for simulating the motility assay systems. Most of the previous models have limitations which precluded full understanding of molecular origins for behaviors of actin filaments. In this study, we used an agent-based computational model based on Brownian dynamics for simulating the motility assay system. Our model rigorously describes the mechanics, dynamics, and interactions of actin filaments, cross-linking proteins, and molecular motors. Using the model, we first investigated how properties of actin filaments and motors affect gliding motions of actin filaments without volume-exclusion effects as a base study. We found that actin filaments can continuously glide at relative fast speed only when they are sufficiently longer than the average spacing between neighboring motors and that the gliding speed of F-actins shows a biphasic dependence on processivity of motors. Then, we showed that volume-exclusion effects between actin filaments can induce diverse collective movements and alignment of actin filaments, thus creating thick bundles and ring-like structures in the absence of cross-linking proteins. Lastly, we demonstrated that cross-linking proteins can lead to distinct contractile behaviors of actin networks depending on the density and kinetics of the cross-linking proteins. Results from our study show the ability of our model to simulate the motility assay system under various conditions and provide insights into understanding of different behaviors of actin filaments.

Mobility of Molecular Motors Regulates Contractile Behaviors of Actin Networks.

Cells generate mechanical forces primarily from interactions between F-actin, cross-linking proteins, myosin motors, and other actin-binding proteins in the cytoskeleton. To understand how molecular interactions between the cytoskeletal elements generate forces, a number of in vitro experiments have been performed but are limited in their ability to accurately reproduce the diversity of motor mobility. In myosin motility assays, myosin heads are fixed on a surface and glide F-actin. By contrast, in reconstituted gels, the motion of both myosin and F-actin is unrestricted. Because only these two extreme conditions have been used, the importance of mobility of motors for network behaviors has remained unclear. In this study, to illuminate the impacts of motor mobility on the contractile behaviors of the actin cytoskeleton, we employed an agent-based computational model based on Brownian dynamics. We find that if motors can bind to only one F-actin like myosin I, networks are most contractile at intermediate mobility. In this case, less motor mobility helps motors stably pull F-actins to generate tensile forces, whereas higher motor mobility allows F-actins to aggregate into larger clustering structures. The optimal intermediate motor mobility depends on the stall force and affinity of motors that are regulated by mechanochemical rates. In addition, we find that the role of motor mobility can vary drastically if motors can bind to a pair of F-actins. A network can exhibit large contraction with high motor mobility because motors bound to antiparallel pairs of F-actins can exert similar forces regardless of their mobility. Results from this study imply that the mobility of molecular motors may critically regulate contractile behaviors of actin networks in cells.

Prevalence of and risk factors for thyroid carcinoma in patients with familial adenomatous polyposis: results of a multicenter study in Japan and a systematic review.

PURPOSE: To investigate the recent Japanese prevalence of thyroid cancer and its characteristics in familial adenomatous polyposis (FAP) patients, through the development of surveillance programs. METHODS: The subjects of this study were 282 (93.1%) FAP patients for whom information on thyroid cancer was available, from among 303 patients registered in "the Retrospective Cohort Study of Familial Adenomatous Polyposis in Japan" database. We evaluated the prevalence and risk factors for thyroid cancer and integrated and/or compared our findings with those of previous reports, using a systematic review, including a meta-analysis. RESULTS: Thyroid cancer was diagnosed in 16 women (11.4%) and 2 men (1.4%), at 17-41 years and 39-57 years of age, respectively. The prevalence of thyroid cancer was 6.4%, with a female-to-male ratio of 8:1, which is comparable to reports from other countries. A young age of < 33 years at the FAP diagnosis and female gender were identified as independent risk factors for thyroid cancer. CONCLUSIONS: FAP-associated thyroid cancer predominantly affects young women, both in Japan and other countries. Since FAP is generally diagnosed when patients are in their 20 s or older, regular screening for thyroid cancer is recommended for all FAP patients, but especially women, from their early 20 s.

Clinical Impact of Preoperative Albumin-Globulin Ratio in Patients with Rectal Cancer Treated with Preoperative Chemoradiotherapy.

OBJECTIVE: The serum albumin-globulin ratio (AGR) is associated with malignancy outcomes. However, among patients with rectal cancer (RC) who undergo neoadjuvant chemoradiotherapy (nCRT), the clinical and prognostic significance of the pretreatment AGR is unclear. METHODS: We investigated whether the pre-nCRT AGR can help predict oncological outcomes in patients with RC receiving nCRT. We analyzed 114 patients with RC who received nCRT followed by total mesorectal excision at our institution. RESULTS: A lower AGR in pre-nCRT serum was significantly correlated with shorter overall survival and disease-free survival in patients with nCRT-treated RC. In multivariate analysis, a high carcinoembryonic antigen (CEA) level and a low AGR in pre-nCRT serum were independent predictors of a poor prognosis in these patients. Furthermore, combining the AGR with CEA provided a more accurate indicator of poor prognosis and early recurrence in these patients. In particular, a low pre-nCRT AGR was a stronger indicator of a poor prognosis and early recurrence in patients without than with pathological lymph node metastasis. Combining the pre-nCRT AGR with CEA could more precisely stratify patients' oncological outcome risks. CONCLUSION: Assessment of the pretreatment AGR with or without CEA can guide postoperative treatment in patients with RC who undergo nCRT.

Colonic Histological Criteria Predict Development of Pouchitis after Ileal Pouch: Anal Anastomosis for Patients with Ulcerative Colitis.

BACKGROUND/AIMS: Pouchitis is one of the main complications after ileal pouch-anal anastomosis in patients with ulcerative colitis. The aim of this study was to determine whether the use of colonic histological criteria can predict the development of pouchitis. METHODOLOGY: We retrospectively reviewed 147 patients' clinical data and performed a histological evaluation of the resected total colon using Tanaka's criteria, which comprise the following 6 factors: ulceration (H1), crypt abscesses (H2), degree of mononuclear cell infiltration (MNCI) (H3), segmental distribution of MNCI (H4), eosinophil infiltration (H5), and extent of disease of resected colon (H6). RESULTS: The development of pouchitis and chronic pouchitis within 3 years after restoration of gastrointestinal continuity was recognized in 52 (35.4%) and 26 (17.7%) of the 147 patients, respectively. Using various combinations of each score, the H3 + H4 - H5 scores of patients with pouchitis or chronic pouchitis were significantly higher than those of patients without. A H3 + H4 - H5 score of >0.4 was a statistically significant risk factor for the development of both pouchitis and chronic pouchitis. CONCLUSIONS: The combination of the degree of MNCI, segmental distribution of MNCI, and eosinophil infiltration from histological criteria has utility in predicting the future development of pouchitis, especially chronic pouchitis.

[Primary Small Bowel Tumor with Simultaneous Lung Metastases from Rectal Cancer - A Case Report].

A 56-year-old woman was diagnosed with rectal cancer and liver metastases(Stage IV), and underwent low anterior resection and laparoscopic partial hepatectomy. The patient received adjuvant chemotherapy(mFOLFOX6 for 24 weeks), but developed multiple lung metastases 11 months later. Before undergoing a pulmonary resection, the patient presented with acute small bowel obstruction. Abdominal computed tomography showed small bowel stenosis due to a tumor, and we suspected peritoneal metastases from the rectal tumor. We performed partial resection of the small intestine, and histopathological examination revealed a primary small bowel tumor. The patient was discharged to her home without complications, and later underwent pulmonary resections for bilateral lung metastases. We usually suspect that small bowel obstruction is due to peritoneal metastases in patients with advanced colorectal tumors, but must consider the rare possibility of a separate primary small bowel tumor, especially in patients with a solitary lesion. We report a rare primary small bowel tumor after FOLFOX treatment in a patient with Stage IV rectal cancer.

Percutaneous fixation of avulsion fracture at the plantar lateral base of the first metatarsal using ZipTight Fixation System: A case report.

Isolated avulsion fracture of the peroneus longus tendon insertion at the base of the first metatarsal without injury of the tarsometatarsal joint is very rare. Similar to most avulsion fractures, this type of injury is caused by strong tension exerted by the peroneus longus tendon. The mechanism leading to this lesion and treatment options are not clearly defined. Several surgical techniques have been advocated for this fracture, including excision of an avulsion fragment and open reduction for internal fixation through the medial aspect of the foot or minimal plantar incision. We have described a method of percutaneous fixing of the avulsion fracture at the plantar lateral base of the first metatarsal using the ZipTight Fixation System (Zimmer Biomet Warsaw, Indiana, USA), which offers the advantage of allowing a rigid fixation and minimal invasive surgical technique for a small fragment.

Clinical significance of SNORA42 as an oncogene and a prognostic biomarker in colorectal cancer.

PURPOSE: Despite recent advances in colorectal cancer (CRC) treatment, the prognosis of patients suffering from this malignancy still remains substandard, and metastatic recurrence following curative surgery is the leading cause of mortality. Therefore, it is imperative to identify prognostic markers to predict the clinical outcome of CRC patients. Recent evidence revealed the new role of small nucleolar RNAs (snoRNAs) in oncogenesis. Herein, we systematically evaluated dysregulation of snoRNAs in CRC and clarified their biomarker potential and biological significance in CRC. EXPERIMENTAL DESIGN: We analysed expression levels of 4 snoRNAs in 274 colorectal tissues from 3 independent cohorts and 6 colon cancer cell lines. The functional characterisation for the role of SNORA42 in CRC was investigated through a series of in vitro and in vivo experiments. RESULTS: In the screening phase, expression levels of all four snoRNAs were significantly elevated in CRC tissues than in corresponding normal mucosa. In the clinical validation cohort, increased SNORA42 expression was an independent prognostic factor for overall survival and disease-free survival, and was a risk factor for distant metastasis. SNORA42 expression negatively correlated with overall survival in an additional independent cohort and identified the patients with high risk for recurrence and poor prognosis in stage II CRC. Furthermore, in vitro and in vivo analyses showed that SNORA42 overexpression resulted in enhanced cell proliferation, migration, invasion, anoikis resistance and tumorigenicity. CONCLUSIONS: SNORA42 appears to be a novel oncogene and could serve as a promising predictive biomarker for recurrence and prognosis in patients with CRC.

Proteomics analysis of differential protein expression identifies heat shock protein 47 as a predictive marker for lymph node metastasis in patients with colorectal cancer.

The discovery of biomarkers to predict the potential for lymph node (LN) metastasis in patients with colorectal cancer (CRC) is essential for developing improved strategies for treating CRC. In the present study, they used isobaric tags for relative and absolute quantitation to conduct a proteomic analysis designed to identify novel biomarkers for predicting LN metastasis in patients with CRC. They identified 60 differentially expressed proteins specifically associated with LN metastasis in CRC patients and classified the molecular and functional characteristics of these proteins by bioinformatic approaches. A literature search led them to select heat shock protein 47 (HSP47) as the most suitable candidate biomarker for predicting LN metastasis. Validation analysis by immunohistochemistry showed that HSP47 expression in patients with CRC and the number of HSP47-positive spindle cells in the tumor stroma were significantly higher compared with those in adjacent normal colonic mucosa, and the number of the latter cells increased with tumor progression. Further, the number of HSP47-positive spindle cells in stroma was a more informative marker for identifying LN metastasis than HSP47expression. Multivariate analysis identified spindle cells that expressed elevated levels of HSP47 as an independent predictive biomarker for CRC with LN metastasis. Moreover, these cells served as an independent marker of disease-free and overall survival of patients with CRC. Their data indicate that the number of HSP47-positive spindle cells in the stroma of CRC may serve as a novel predictive biomarker of LN metastasis, early recurrence and poor prognosis.

Mechanical role of the spatial patterns of contractile cells in invagination of growing epithelial tissue.

Epithelial invagination is one of the fundamental deformation modes during morphogenesis, and is essential for deriving the three-dimensional shapes of organs from a flat epithelial sheet. Invagination occurs in an orderly manner according to the spatial pattern of the contractile cells; however, it remains elusive how tissue deformation can be caused by cellular activity in the patterned region. In this study, we investigated the mechanical role of the spatial patterns of the contractile cells in invagination of growing tissue using multicellular dynamics simulations. We found that cell proliferation and apical constriction were responsible for expanding the degree of tissue deformation and determining the location of the deformation, respectively. The direction of invagination depended on the spatial pattern of the contractile cells. Further, comparing the simulation results of surface and line contractions as possible modes of apical constriction, we found that the direction of invagination differed between these two modes even if the spatial pattern was the same. These results indicate that the buckling of the epithelial cell sheet caused by cell proliferation causes the invagination, with the direction and location determined by the configuration of the wedge-shaped cells given by the spatial pattern of the contractile cells.