SoxB family genes delay regeneration and cause abnormal movement in Dugesia japonica.

SoxB subfamily is an important branch of Sox family and plays a key role in animal physiological process, but little is known about their function in planarian regeneration. This study aims to evaluate the function of DjSoxB family genes in intact and regenerating planarians Dugesia japonica. Here, we amplify the full-length cDNA of DjSoxB1 and DjSoxB2 in D. japonica by rapid amplification of the cDNA ends (RACE), detect the expression of DjSoxB family genes in planarian. The results show that DjSoxBs are expressed in parenchymal tissue and the hybridization signals partially disappear after irradiation indicates DjSoxB family genes are expressed in neoblasts. After the RNA interference (RNAi) of DjSoxB1, DjSoxB2 and DjSoxB3 separately, the numbers of proliferative cells are all reduced that causes planarians show slower growth of blastema in the early stage of regeneration, and nerves of planarians are affected that the movement speed of planarians decreases in varying degrees. Specially, planarians in the DjSoxB3 RNAi group show shrinkage and twisting. Overall, this study reveals that DjSoxB family genes play a role in cell proliferation during regeneration. They also play an important role in the maintenance of normal nerve function and nerve regeneration. These results provide directions for the functional study of SoxB family genes and provide an important foundation for planarian regeneration.

Ecotoxicological evaluation and regeneration impairment of planarians by dibutyl phthalate.

Commonly utilized as a plasticizer in the food and chemical sectors, Dibutyl phthalate (DBP) poses threats to the environment and human well-being as it seeps or moves into the surroundings. Nevertheless, research on the harmfulness of DBP to aquatic organisms is limited, and its impact on stem cells and tissue regeneration remains unidentified. Planarians, recognized for their robust regenerative capabilities and sensitivity to aquatic pollutants, are emerging animal models in toxicology. This study investigated the comprehensive toxicity effects of environmentally relevant levels of DBP on planarians. It revealed potential toxicity mechanisms through the use of immunofluorescence, chromatin dispersion assay, Western blot, quantitative real-time fluorescence quantitative PCR (qRT-PCR), chromatin behavioral and histological analyses, immunofluorescence, and terminal dUTP nickel-end labeling (TUNEL). Findings illustrated that DBP caused morphological and motor abnormalities, tissue damage, regenerative inhibition, and developmental neurotoxicity. Further research revealed increased apoptosis and suppressed stem cell proliferation and differentiation, disrupting a balance of cell proliferation and death, ultimately leading to morphological defects and functional abnormalities. This was attributed to oxidative stress and DNA damage caused by excessive release of reactive oxygen species (ROS). This exploration furnishes fresh perspectives on evaluating the toxicity peril posed by DBP in aquatic organisms.

The collectin subfamily member 11 (Ca-Colec11) from Qihe crucian carp (Carassius auratus) agglutinates and inhibits Aeromonas hydrophila and Staphylococcus aureus.

The collectin subfamily member 11 (Colec11), plays an important role in innate immunity as a pattern recognition molecule. In the present study, a colec11 homolog was identified and characterised from Qihe crucian carp, namely, Ca-colec11. The full-length cDNA of Ca-colec11 was composed of 1129 bp, with a 99 bp 5'-untranslated region (UTR), 816 bp open reading frame (ORF) encoding a 271-aa protein and 214 bp 3'-UTR with a polyadenylation signal sequence (aataaa) and a poly(A) tail. The deduced amino acid sequence of Ca-Colec11 contained a si gnal peptide, collagen domain, neck region and carbohydrate-recognition domain (CRD), which had four conserved cysteine residues (Cys170-Cys256 and Cys242-Cys264) and an EPN/WND motif required for carbohydrate-binding specificity. Tissue expression profile analysis by quantitative real-time polymerase chain reaction (RT-qPCR) showed that Ca-colec11 was ubiquitously distributed in the tested tissues and highly expressed in the liver. The gene expression levels of Ca-colec11 were evidently up-regulated in the liver, spleen, kidney and head kidney after infection with A. hydrophila and S. aureus. The recombinant Ca-Colec11 (rCa-Colec11) purified from Escherichia coli BL21 (DE3) could agglutinate A. hydrophila and S. aureus, and it possessed haemagglutination activity against rabbit erythrocytes, which was inhibited by various carbohydrates, including d-Mannose, N-Acetyl-d-mannosamine, l-Fucose, d-Glucose, N-Acetyl-d-glucosamine, d-Galactose, LPS and PGN. Furthermore, rCa-Colec11 could inhibit the growth of A. hydrophila and S. aureus. These findings collectively demonstrated that Ca-Colec11, as a PRR, could play a role in the immune defence of Qihe crucian carp.

Influence of Co3O4 Nanostructure Morphology on the Catalytic Degradation of p-Nitrophenol.

The design and fabrication of nanomaterials with controllable morphology and size is of critical importance to achieve excellent catalytic performance in heterogeneous catalysis. In this work, cobalt oxide (Co3O4) nanostructures with different morphologies (nanoplates, microflowers, nanorods and nanocubes) were successfully constructed in order to establish the morphology-property-performance relationship of the catalysts. The morphology and structure of the nanostructured Co3O4 were characterized by various techniques, and the catalytic performance of the as-prepared nanostructures was studied by monitoring the reduction of p-nitrophenol to p-aminophenol in the presence of excess NaBH4. The catalytic performance was found to be strongly dependent on their morphologies. The experimental results show that the pseudo-first-order reaction rate constants for Co3O4 nanostructures with various shapes are, respectively, 1.49 min-1 (nanoplates), 1.40 min-1 (microflowers), 0.78 min-1 (nanorods) and 0.23 min-1 (nanocubes). The Co3O4 nanoplates exhibited the highest catalytic activity among the four nanostructures, due to their largest specific surface area, relatively high total pore volume, best redox properties and abundance of defect sites. The established correlation between morphology, property and catalytic performance in this work will offer valuable insight into the design and application of nanostructured Co3O4 as a potential non-noble metal catalyst for p-nitrophenol reduction.

Neurotoxicity of Glyphosate to Planarian Dugesia japonica.

As one of the most widely used herbicides in agricultural industry, the residues of glyphosate (GLY) are frequent environmental pollutants. Freshwater planarian Dugesia japonica has been developed as a model for neurotoxicology. In this study, the effects of GLY on locomotion and feeding behavior, as well as neuroenzyme activities and mRNA expressions of D. japonica were determined. Additionally, histochemical localization was executed to explore the damage to the central nervous system (CNS) of planarians stressed by GLY. The results showed that the locomotor velocity, ingestion rate and the neuroenzyme activity were inhibited and the gene expressions were altered. Also, histo-architecture injury to CNS of planarians upon GLY exposure in a time-dependent manner was observed. Collectively, our results indicate that GLY can cause neurotoxicity to freshwater planarians representing as reduction in locomotor velocity and feeding rate by disturbing the neurotransmission systems and damaging the structure of CNS.

Autophagy-related DjAtg1-1 plays critical role in planarian regeneration by regulating proliferation and cell death.

Autophagy is an intracellular degradation process and plays key roles in energy recycle and homeostasis maintenance during planarian regeneration. Although planarians provide an ideal model organism for studying autophagy in vivo, the molecular mechanism of planarian autophagy is still unknown. Here, we identify three autophagy-related (Atg) gene 1 homologs from Dugesia japonica and study their roles in planarian regeneration. Both DjATG1-1 and DjATG1-2 proteins show homology to vertebrate unc-51 like autophagy activating kinase 1 (ULK1) and ULK2, DjATG1-3 shows homology to vertebrate ULK3. In contrast to the ubiquitously expressed DjAtg1-1 and DjAtg1-3, DjAtg1-2 is mainly expressed in the intestine branches and epidermis. All the three DjAtg1s can respond to planarian regeneration and starvation. Both DjAtg1-1 and DjAtg1-2 are expressed in the reproductive organs of the starved sexual worms. DjAtg1-1 or DjAtg1-3 RNAi leads to head lysis and death of starved planarians, accompanied by exhaustion of neoblasts. DjAtg1-1 RNAi causes autophagy and regeneration defects and decreases proliferation and cell death; both DjAtg1-2 and DjAtg1-3 RNAi cause no autophagy or regeneration defect but increase cell death during regeneration. Our findings uncover the roles of DjAtg1s in autophagy and regeneration of planarian and highlight the links between proliferation, cell death, and autophagy during regeneration.

The application of apparent diffusion coefficients derived from intratumoral and peritumoral zones for assessing pathologic prognostic factors in rectal cancer.

OBJECTIVE: To investigate the diagnostic performance of the apparent diffusion coefficient (ADC) derived from intratumoral and peritumoral zones for assessing pathologic prognostic factors in rectal cancer. MATERIALS AND METHODS: One hundred forty-six patients with rectal cancer who underwent preoperative MRI were prospectively enrolled. Two radiologists independently placed free-hand regions of interest (ROIs) in the largest tumor cross section and three small ROIs on the peritumoral zone adjacent to the tumor contour. Maximum values of tumor ADC (ADCtmax), minimum values of tumor ADC (ADCtmin), mean values of tumor ADC (ADCtmean), mean values of peritumor ADC (ADCpmean), and ADCpmean/ADCtmean (ADC ratio) were obtained on ADC maps and correlated with prognostic factors using uni- and multivariate logistic regression, and receiver operating characteristic curve (ROC) analysis. RESULTS: Interobserver agreement was excellent for ADCtmax and ADCtmean (intraclass correlation coefficient [ICC], 0.915-0.958), and were good for ADCtmin, ADCpmean, and ADC ratio (ICC, 0.774-0.878). The ADC ratio was significantly higher in the poor differentiation, T3-4 stage, lymph node metastasis (LNM)-positive, extranodal extension (ENE)-positive, tumor deposit (TD)-positive, and lymphovascular invasion (LVI)-positive groups than that in the well-moderate differentiation, T1-2 stage, LNM-negative, ENE-negative, TD-negative, and LVI-negative groups (p = 0.008, < 0.001, < 0.001, 0.001, < 0.001, and < 0.001, respectively). The area under the ROC curve (AUC) of the ADC ratio was the highest for assessing poor differentiation (0.700), T3-4 stage (0.707), LNM-positive (0.776), TD-positive (0.848), and LVI-positive (0.778). Both the ADC ratio (AUC = 0.677) and ADCpmean (AUC = 0.686) showed higher diagnostic performance for assessing ENE. CONCLUSION: The ADC ratio could provide better predictive performance for assessing preoperative prognostic factors in resectable rectal cancer. KEY POINTS: • Both the peritumor/tumor ADC ratio and ADCpmean are correlated with important prognostic factors of resectable rectal cancer. • Both peritumor ADC and peritumor/tumor ADC ratio had higher diagnostic performance than tumor ADC for assessment of prognostic factors in resectable rectal cancer. • Peritumor/tumor ADC ratio showed the most capability for the assessment of prognostic factors in resectable rectal cancer.

PBDEs disrupt homeostasis maintenance and regeneration of planarians due to DNA damage, proliferation and apoptosis anomaly.

Polybrominated diphenyl ethers (PBDEs) are widely used as brominated flame retardants in the manufacturing industry, belonging to persistent organic pollutants in the environment. Planarians are the freshwater worms, with strong regenerative ability and extreme sensitivity to environmental toxicants. This study aimed to evaluate the potential acute comprehensive effects of PBDE-47/-209 on freshwater planarians. Methods to detect the effects include: detection of oxidative stress, observation of morphology and histology, detection of DNA fragmentation, and detection of cell proliferation and apoptosis. In the PBDE-47 treatment group, planarians showed increased oxidative stress intensity, severe tissue damage, increased DNA fragmentation level, and increased cell proliferation and apoptosis. In the PBDE-209 treatment group, planarians showed decreased oxidative stress intensity, slight tissue damage, almost unchanged DNA fragmentation level and apoptosis, proliferation increased only on the first day after treatment. In conclusion, both PBDE-47 and PBDE-209 are dangerous environmental hazardous material that can disrupt planarians homeostasis, while the toxicity of PBDE-47 is sever than PBDE-209 that PBDE-47 can lead to the death of planarians.

Diffusion-weighted MR volume and apparent diffusion coefficient for discriminating lymph node metastases and good response after chemoradiation therapy in locally advanced rectal cancer.

OBJECTIVE: To determine diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) volume and apparent diffusion coefficient values (ADCs) for assessing lymph node metastases (LNM) and good response after chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: This retrospective study consisted of 61 patients with LARC who underwent pre- and post-CRT DW images. Two radiologists independently placed free-hand regions of interest in each tumor-containing section on DW images to calculate pre- and post-CRT tumor volume and tumor volume reduction rates (Δvolume). Regions of interest were drawn to include tumor on maximum cross-sectional slice to obtain ADCs. Areas under the receiver operating characteristic curves (AUCs) were calculated to evaluate diagnostic performance in identifying LNM and good response after CRT using these parameters. RESULTS: Inter-observer agreement and intra-observer agreement were excellent for pre- and post-CRT DW MR volume (intraclass correlation coefficient [ICC], 0.889-0.948) and moderate for pre- and post-CRT ADCs (ICC, 0.535-0.811). AUCs for identifying LNM were 0.508 for pre-CRT DW MR volume versus 0.705 for pre-CRT ADC, 0.855 for post-CRT DW MR volume versus 0.679 for post-CRT ADC, and 0.887 for Δvolume versus 0.533 for ΔADC. AUCs for identifying good response were 0.518 for pre-CRT volume versus 0.506 for pre-CRT ADC, 0.975 for post-CRT volume versus 0.723 for post-CRT ADC, and 0.987 for Δvolume versus 0.655 for ΔADC. CONCLUSION: DW MR Δvolume provided high diagnostic performance in discriminating LNM after CRT. DW MR Δvolume was equally as accurate as post-CRT DW MR volume for evaluating good response. KEY POINTS: • Inter-observer agreement and intra-observer agreement were excellent for pre- and post-CRT DW MR volume (intraclass correlation coefficient [ICC], 0.889-0.948) and moderate for pre- and post-CRT ADCs (ICC, 0.535-0.811). • DW MR Δvolume provided high diagnostic performance in identifying LNM after CRT (AUC, 0.887) and good response (AUC, 0.987) and was significantly more accurate than pre-CRT DW MR volume (AUC, 0.508 and 0.518, respectively) and ADCs (AUC, 0.705 and 0.506, respectively). • DW MR Δvolume (AUC, 0.987) was equally as accurate as post-CRT DW MR volume (AUC, 0.975) for evaluating good response, while pre-CRT DW MR volume and ADCs were not reliable for evaluating LNM and good response after CRT (AUC, 0.506-0.723).

Antioxidant responses and lipid peroxidation can be used as sensitive indicators for the heavy metals risk assessment of the Wei River: a case study of planarian Dugesia Japonica.

PURPOSE: To verify antioxidant responses and lipid peroxidation can be used as sensitive indicators for the risk assessment of the Wei River. MATERIAL AND METHODS: We investigate the effects of the Wei River on oxidative stress of planarian Dugesia japonica by antioxidant parameters, and use ICP-MS to measure the heavy metals in the Wei River. Then, we observe the effects of three common heavy metal ions (Cr3+, Hg2+, Pb2+) on the regeneration of planarians on morphological and histological levels. RESULTS: The significant changes of antioxidant parameters (SOD, CAT, GPx, GST, T-AOC) and MDA content indicate that oxidative stress is induced after the Wei River exposure on planarians, though the heavy metals in the Wei River are not exceeding the standards. Then, the regeneration of planarians shows different degree of morphological and histological damage after Cr3+, Hg2+ and Pb2+ exposure. CONCLUSION: We speculate that the heavy metal ions in the Wei River, especially Cr3+, Hg2+ and Pb2+, may give rise to oxidative damage on planarians. These findings illustrate that planarian can serve as an indicator of aquatic ecosystem pollution, antioxidant responses and lipid peroxidation can also be used as sensitive indicators and provide an excellent opportunity for urban river risk assessment.

The negative effect of the PI3K inhibitor 3-methyladenine on planarian regeneration via the autophagy signalling pathway.

As an important PI3K (VPS34) inhibitor, 3-methyladenine (3-MA) can block the formation of autophagic vesicles in animals. Most toxicological studies using 3-MA have shown that 3-MA leads to serious disorders via autophagy suppression in mammals. However, no toxicological research on 3-MA has been performed on individuals undergoing regeneration. The freshwater planarian has powerful regenerative capability, and it can regenerate a new brain in 5 days and undergo complete adult individual remodelling in approximately 14 days. Moreover, it is also an excellent model organism for studies on environmental toxicology due to its high chemical sensitivity and extensive distribution. Here, Dugesia japonica planarians were treated with 3-MA, and the results showed that autophagy was inhibited and Djvps34 expression levels were down-regulated. After exposure to 10 mM 3-MA for 18 h, all the controls showed normal phenotypes, while one-half of the planarians treated with 3-MA showed morphological defects. In most cases, an ulcer appeared in the middle of the body, and a normal phenotype was restored 7 days following 3-MA exposure. During regeneration, disproportionate blastemas with tissue regression were observed. Furthermore, 3-MA treatment suppressed stem cell proliferation in intact and regenerating worms. These findings demonstrate that autophagy is indispensable for tissue homeostasis and regeneration in planarians and that 3-MA treatment is detrimental to planarian regeneration via its effect on the autophagy pathway.

[Functional analysis of autophagy-related gene Atg6 in planarian central nervous system regeneration].

Autophagy-related gene 6 (Atg6) plays an essential role in autophagy, and loss of its function impairs neurogenesis. Planarian is a good model for the study of the central nervous system (CNS) regeneration. It can regenerate a new head de novo in 1 week following decapitation. Therefore, functional analysis of Atg6 in planarian CNS regeneration is very important for understanding of autophagy in the regulation of neurogenesis. In this work, we reported the molecular characteristics of Atg6 in Dugesia japonica (DjAtg6) for the first time and examined its function by RNAi. The full-length cDNA of DjAtg6 is 1366 bp encoding 423 amino acids. The deduced amino sequence of DjAtg6 contains the coil-coil domain and ß-α-repeated autophagy-specific domain shared by ATG6/Beclin 1 family. Following amputation before and after the pharynx, DjAtg6 transcripts increased and were mainly distributed in the newly regenerated brain structure. RNAi-DjAtg6 delayed planarian head regeneration with a small size of brain, and decreased the expression levels of neural-related genes. In addition, our results revealed that RNAi-DjAtg6 did not affect the stem cell proliferation, but down-regulated the cell migration-related genes mmp1 and mmp2. Furthermore, RNAi-mmp1 and RNAi-mmp2 delayed planarian head regeneration. Therefore, our results suggest that DjAtg6 is important for planarian CNS regeneration. The abnormal CNS regeneration caused by RNAi-DjAtg6 may be related to cell migration, but the detailed mechanism needs to be further investigated.

circRNA-14723 promotes hepatocytes proliferation in rat liver regeneration by sponging rno-miR-16-5p.

Circular RNA (circRNA) is a subclass of noncoding RNA (ncRNA) detected within mammalian tissues and cells. However, its regulatory role during the proliferation phase of rat liver regeneration (LR) remains unreported. This study was designed to explore their regulatory mechanisms in cell proliferation of LR. The circRNA expression profile was detected by high-throughput sequencing. It was indicated that 260 circRNAs were differentially expressed during the proliferation phase of rat LR. Among them, circ-14723 displayed a significantly differential expression. We further explored its regulatory mechanism in rat hepatocytes (BRL-3A cells). First, EdU, flow cytometry and western blot (WB) indicated that knocking down circ-14723 inhibited BRL-3A cells proliferation. Second, RNA-Pulldown and dual-luciferase report assay showed that circ-14723 could sponge rno-miR-16-5p. At last, WB showed that the reported target genes of rno-miR-16-5p, CCND1, and CCNE1 were downregulated after knocking down circ-14723. In conclusion, we found that circ-14723 exerted a critical role in G1/S arrest to promote cell proliferation via rno-miR-16-5p/CCND1 and CCNE1 axis in rat LR. This finding further revealed the regulatory mechanisms of circRNA on cell proliferation of LR, and might provide a potential target for clinical problems.

Djmek is involved in planarian regeneration by regulation of cell proliferation and apoptosis.

Dugesia japonica, belonging to Platyhelminthes, plays an important role in the animal evolution and is well known for its extraordinary regenerative ability. Mitogen activated protein kinase (MAPK) pathway is an important cell signaling pathway that converts extracellular stimuli into a wide range of cellular responses. The MAP-extracellular signal-regulated kinase (MEK) is a main component of MAPK/ERK signaling, but there are few studies on mek gene in planarians. In this study, we observe the expression patterns of Djmek1 and Djmek2 in planarians, and find that both of the two genes are required for the planarian regeneration. At the same time, we also find that both Djmek1 and Djmek2 are involved in the planarian regeneration by regulation of cell proliferation and apoptosis. Together, our findings show that the functions of the two genes are similar and complementary, and they play an important role in the regeneration of planarians.

Expression and functional analysis of flotillins in Dugesia japonica.

FLOTILLIN-1 and FLOTILLIN-2 are membrane rafts associated proteins that have been implicated in insulin and growth factor signaling, endocytosis, cell migration, proliferation, differentiation, cytoskeleton remodeling and membrane trafficking. Furthermore, FLOTILLINs also play important roles in the progression of cancer and neurodegenerative diseases. In this study, the roles of flotillins are investigated in planarian Dugesia japonica. The results show that Djflotillin-1 and Djflotillin-2 play a key role in homeostasis maintenance and regeneration process by regulating the proliferation of the neoblast cells, they are not involved in the maintenance and regeneration of the central nervous system in planarians.

A novel sigma class glutathione S-transferase gene in freshwater planarian Dugesia japonica: cloning, characterization and protective effects in herbicide glyphosate stress.

As the top-selling herbicide in the world, glyphosate distributes widely in natural environment and its influence on the ecological security and human health has attracted more and more concern. Glutathione S-transferases (GSTs) are a well-characterized superfamily of isoenzymes for cellular defense against exogenous toxic substances and therefore protect organisms from injury. In this study, the complete cDNA sequence of GST gene (named as Dja-GST) in freshwater planarian Dugesia japonica was firstly cloned by means of RACE method. The full-length Dja-GST comprises of 706 nucleotides which encodes a polypeptide of 200 amino acids. Dja-GST has two representative GST domains at the N- and C-termini. The conservative GST-N domain includes G-site Y8, F9, R14, W39, K43, P52 and S64, while the variable GST-C domain contains H-site K104, V156, D159 and L161. Sequence analysis, phylogenetic tree reconstruction and multiple alignment collectively indicate that Dja-GST belongs to the Sigma class of GST superfamily. Also, GST gene expression profile, GST enzymatic activity and MDA content in response to glyphosate exposure were systematically investigated and the correlations among them were analyzed. The results suggest that glyphosate exposure modified the mRNA transcription and enzymatic activity of GST, as well as the MDA content in planarians, indicating that Dja-GST might play an important part in organisms defending against oxidative stress induced by glyphosate. This work lays a molecular foundation for further exploring the exact functions of Dja-GST and gives an important implication for evaluating the ecological environment effects of herbicide glyphosate.

Biomarkers of Planarian Dugesia japonica in Response to Herbicide Glyphosate Exposure.

As the worldwide top-selling herbicide, glyphosate is ubiquitously distributed in the natural environment, and its influence on the ecological safety and human health has being increasingly concerned. In this study, mRNA expressions of GPX and three heat shock protein genes in freshwater planarian Dugesia japonica in response to glyphosate were determined, and two oxidative stress parameters were measured. The results suggested that GPX activity can be used as a more sensitive biomarker in contrast with GPX gene expression, and mRNA expressions of Hsp70, Hsp90 genes are more sensitive than Hsp40 for planarians in response to glyphosate stress. Besides, the deduced T-AOC as well as varied GPX activity and mRNA expression levels of Hsps also indicated that glyphosate exposure would inhibit antioxidation and induce oxidative stress in D. japonica, while specific antioxidant systems and stress proteins tried to protect cells by their own regulation. The results of this study will be helpful to elucidate the stress response mechanisms of freshwater planarians to herbicide glyphosate.

DWI and T2-Weighted MRI Volumetry in Resectable Rectal Cancer: Correlation With Lymphovascular Invasion and Lymph Node Metastases.

OBJECTIVE. The purpose of this study was to assess whether MR volumetric data on DW and T2-weighted MR images are correlated with lymphovascular invasion and lymph node metastases in resectable rectal cancer. MATERIALS AND METHODS. This retrospective study consisted of 50 consecutive patients with rectal cancer who underwent radical surgery within 1 week of MRI. The gross tumor volume was determined on both diffusion-weighted and T2-weighted MR images and correlated with pathologic lymphovascular invasion and lymph node metastases using univariate, multivariate, and ROC curve analyses. RESULTS. Both gross tumor volume values showed correlations with lymphovascular invasion (r = 0.750 vs r = 0.710; p < 0.0001) and lymph node metastases (r = 0.780 vs r = 0.755; p < 0.0001). Both values were associated with lymphovascular invasion and lymph node metastases in univariate analysis (all p < 0.0001), whereas only the DWI-based value was an independent risk factor for lymphovascular invasion (odds ratio = 1.207; p = 0.005) and lymph node metastases (odds ratio = 1.420; p = 0.005) in multivariate analysis. Both values could distinguish between N0 and N1, N0 and N1-N2, and N0-N1 and N2 disease (all p < 0.0001) in the Mann-Whitney U test. The area under the ROC curve was higher for the DWI-based value in lymphovascular invasion (0.899 vs 0.877), N0 vs N1 (0.865 vs 0.827), N0 vs N1-N2 (0.934 vs 0.911), and N0-N1 vs N2 (0.932 vs 0.927). CONCLUSION. Tumor volumetry data correlated with both lymphovascular invasion and lymph node metastases in resectable rectal cancer. In particular, the DWI-based gross tumor volume showed the most potential for noninvasive preoperative evaluation of lymphovascular invasion and lymph node metastases.

The regulation of rapamycin in planarian Dugesia japonica Ichikawa & Kawakatsu, 1964 regeneration according to TOR signaling pathway.

The freshwater planarian mostly lives in the upper reaches of springs and rivers. Generally, it is realized as a suitable warning indicator of environmental toxicants. The freshwater planarian Dugesia japonica has a powerful regenerative capability and can regenerate a new individual including a complete central nervous system in one week. Rapamycin is an inhibitor of mammalian TORC1 (target of rapamycin complex-1) and used in the treatment of some diseases like cancer, cardiovascular and neurological diseases. However, the roles of rapamycin in the regulation of planarian regeneration remain to be elucidated. In present study, freshwater planarians D. japonica were firstly treated with 1 µM rapamycin for 18 h exposures and the expression patterns of Djtor was analyzed by the whole-mount in situ hybridization (WISH). Our results indicated rapamycin could strongly inhibit Djtor expression in planarian D. japonica and cause asymmetric blastemas and neuronal defects in planarians. Furthermore, knockdown of Djtor gene in planarians using RNA interference resulted in the suppression of downstream autophagy genes. These findings suggested that rapamycin might regulate freshwater planarian regeneration via Djtor signaling pathway.

Identification of a potential tissue-specific biomarker cathepsin L-like gene from the planarian Dugesia japonica: Molecular cloning, characterization, and expression in response to heavy metal exposure.

Heavy metal pollution is a global health issue affecting people worldwide, and the exploration of sensitive biomarkers to assess the toxicity of heavy metals is an important work for researchers. Cathepsin L, role as a tissue-specific biomarker to assess the biological effects of environmental pollutants, has not received much attention. In this work, the full-length cDNA of cathepsin L gene from the planarian Dugesia japonica (designated DjCatL) was cloned by rapid amplification of cDNA ends (RACE) technique. The cDNA sequence of DjCatL is 1161 bp, which encodes a protein of 346 amino acids with a molecular weight of 39.03 kDa. Sequence analysis revealed that DjCatL contains highly conserved ERF/WNIN, GNFD, and GCXGG motifs, which are the features of the cathepsin L protein family. Whole-mount in situ hybridization (WISH) results revealed that the transcripts of DjCatL are specifically distributed in the intestinal system, suggesting that this gene is related to food digestion in planarians. Both quantitative polymerase chain reaction (qPCR) and WISH results revealed that the transcriptional levels of DjCatL are inhibited significantly by heavy metal (Cd2+, Hg2+, and Cu2+) exposure in a dose-dependent manner. Therefore, we proposed that cathepsin L can be used as a tissue-specific biomarker to assess the heavy metal pollution in the aquatic environment.