Tenascin-C regulates recruitment of myofibroblasts during tissue repair after myocardial injury

Tenascin-C (TN-C) is an extracellular matrix molecule that is expressed during wound healing in various tissues. Although not detectable in the normal adult heart, it is expressed under pathological conditions. Previously, using a rat model, we found that TN-C was expressed during the acute stage after myocardial infarction and that alpha-smooth muscle actin (alpha-SMA)-positive myofibroblasts appeared in TN-C-positive areas. In the present study, we examined whether TN-C controls the dynamics of myofibroblast recruitment and wound healing after electrical injury to the myocardium of TN-C knockout (TNKO) mice compared with wild-type (WT) mice. In TNKO mice, myocardial repair seemed to proceed normally, but the appearance of myofibroblasts was delayed. With cultured cardiac fibroblasts, TN-C significantly accelerated cell migration, alpha-SMA expression, and collagen gel contraction but did not affect proliferation. Using recombinant fragments of murine TN-C, the functional domain responsible for promoting migration of cardiac fibroblasts was mapped to the conserved fibronectin type III (FNIII)-like repeats and the fibrinogen (Fbg)-like domain. Furthermore, alternatively spliced FNIII and Fbg-like domains proved responsible for the up-regulation of alpha-SMA expression. These results indicate that TN-C promotes recruitment of myofibroblasts in the early stages of myocardial repair by stimulating cell migration and differentiation.

Ectopic expression of a tobacco homeobox gene, NTH15, dramatically alters leaf morphology and hormone levels in transgenic tobacco

The shoot apical meristem functions to generate the lateral organs of a plant throughout the vegetative and reproductive phases. Homeobox genes play key roles in controlling such developmental programs, but their modes of action have not been well defined. Here we describe isolation and biological functions of a novel tobacco homeobox gene, designated NTH15 (Nicotiana tabacum homeobox 15), from a tobacco shoot apex cDNA library. NTH15 encodes a polypeptide of 342 amino acids, its homeodomain is very similar to the class 1 KNOTTED-type homeodomains. NTH15 mRNA is mainly localized in corpus cells in the tobacco shoot apical meristem, but not in tunica layers nor in differentiated lateral organs. The NTH15 cDNA was fused to the cauliflower mosaic virus 35S promoter and used to generate transgenic tobacco plants. Almost all transgenic tobacco plants showed abnormal leaf and/or flower morphology, and were categorized into three groups depending on severity of the leaf phenotype. In transgenic leaves, drastic decrease of GA1 and increase of cytokinin were observed, while the levels of other phytohormones were only slightly changed. Taken together, our results suggest NTH15 is involved in tobacco morphogenesis and abnormal leaf morphology in transgenic plants results from altered hormone levels.

Alteration of hormone levels in transgenic tobacco plants overexpressing the rice homeobox gene OSH1

The rice (Oryza sativa L.) homeobox gene OSH1 causes morphological alterations when ectopically expressed in transgenic rice, Arabidopsis thaliana, and tobacco (Nicotiana tabacum L.) and is therefore believed to function as a morphological regulator gene. To determine the relationship between OSH1 expression and morphological alterations, we analyzed the changes in hormone levels in transgenic tobacco plants exhibiting abnormal morphology. Levels of the plant hormones indole-3-acetic acid, abscisic acid, gibberellin (GA), and cytokinin (zeatin and trans-zeatin [Z]) were measured in leaves of OSH1-transformed and wild-type tobacco. Altered plant morphology was found to correlate with changes in hormone levels. The more severe the alteration in phenotype of transgenic tobacco, the greater were the changes in endogenous hormone levels. Overall, GA1 and GA4 levels decreased and abscisic acid levels increased compared with wild-type plants. Moreover, in the transformants, Z (active form of cytokinin) levels were higher and the ratio of Z to Z riboside (inactive form) also increased. When GA3 was supplied to the shoot apex of transformants, internode extension was restored and normal leaf morphology was also partially restored. However, such GA3-treated plants still exhibited some morphological abnormalities compared with wild-type plants. Based on these data, we propose the hypothesis that OSH1 affects plant hormone metabolism either directly or indirectly and thereby causes changes in plant development.

The expression of tobacco knotted1-type class 1 homeobox genes correspond to regions predicted by the cytohistological zonation model

We have isolated and characterized four tobacco homeobox genes, NTH1, NTH9, NTH20, NTH22 (Nicotiana tabacum homeobox) which belong to the class 1 knotted1-type family of homeobox genes. Comparison of the inferred amino acid sequences of the ELK homeodomains of these genes and previously reported kn1-type class 1 proteins has revealed that the four new tobacco genes belong to distinct subclasses, suggesting that each NTH gene may have distinct functions. Using in situ hybridization and by analysing the distribution of GUS activity in tobacco plants transformed with NTH promoter::GUS constructs, localized expression of the three NTH genes was observed in the shoot apical meristem (SAM). In the vegetative SAM, NTH1 and NTH15 showed overlapping expression in the corpus, NTH20 was expressed in the peripheral zone, and NTH9 was predominantly expressed in the rib zone. The expression patterns of the different NTH genes correspond to regions predicted by the cytohistological zonation model, suggesting that each NTH gene specifies the function of the SAM zone with which it is associated.

Identification and Characterization of CXCR4-Positive Gastric Cancer Stem Cells

Diffuse-type solid tumors are often composed of a high proportion of rarely proliferating (i.e., dormant) cancer cells, strongly indicating the involvement of cancer stem cells (CSCs) Although diffuse-type gastric cancer (GC) patients have a poor prognosis due to high-frequent development of peritoneal dissemination (PD), it is limited knowledge that the PD-associated CSCs and efficacy of CSC-targeting therapy in diffuse-type GC. In this study, we established highly metastatic GC cell lines by in vivo selection designed for the enrichment of PD-associated GC cells. By microarray analysis, we found C-X-C chemokine receptor type 4 (CXCR4) can be a novel marker for highly metastatic CSCs, since CXCR4-positive cells can grow anchorage-independently, initiate tumors in mice, be resistant to cytotoxic drug, and produce differentiated daughter cells. In clinical samples, these CXCR4-positive cells were found from not only late metastasis stage (accumulated ascites) but also earlier stage (peritoneal washings). Moreover, treatment with transforming growth factor-β enhanced the anti-cancer effect of docetaxel via induction of cell differentiation/asymmetric cell division of the CXCR4-positive gastric CSCs even in a dormant state. Therefore, differentiation inducers hold promise for obtaining the maximum therapeutic outcome from currently available anti-cancer drugs through re-cycling of CSCs.

Over-expression of tobacco knotted1-type class1 homeobox genes alters various leaf morphology

We compared the phenotypes of transgenic tobacco plants over-expressing various knotted1-type class1 homeobox genes. All transformants showed abnormal leaf morphology, with the degree of abnormality depending upon the Nicotiana tabacum homeobox (NTH) gene that was over-expressed. Tobacco plants over-expressing NTH1 or NTH9 showed a relatively weak phenotype, while NTH15 and NTH20 over-expressing plants exhibited severe alterations, with occasional ectopic shoot formation on the leaves. Plants over-expressing NTH22 had a relatively severe phenotype, but did not form any ectopic shoots. These results indicate that all of the NTH genes can influence leaf development from the shoot apical meristem, but that the effect varies with the gene. Based on phylogenetic analysis of the NTH genes and comparison of the phenotypes of plants over-expressing them, we suggest that the kn1-type class1 family can be divided into two subgroups, and that the differences in their ability to induce the abnormal phenotype corresponds to the structures of their conserved domains.

SIX1 maintains tumor basal cells via transforming growth factor-β pathway and associates with poor prognosis in esophageal cancer

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors. Although improvement in both surgical techniques and neoadjuvant chemotherapy has been achieved, the 5-year survival rate of locally advanced tumors was, at best, still 55%. Therefore, elucidation of mechanisms of the malignancy is eagerly awaited. Epithelial-mesenchymal transition (EMT) by transforming growth factor-β (TGF-β) has been reported to have critical biological roles for cancer cell stemness, whereas little is known about it in ESCC. In the current study, a transcriptional factor SIX1 was found to be aberrantly expressed in ESCCs. SIX1 cDNA transfection induced overexpression of transforming growth factors (TGFB1 and TGFB2) and its receptor (TGFBR2). Cell invasion was reduced by SIX1 knockdown and was increased in stable SIX1-transfectants. Furthermore, the SIX1-transfectants highly expressed tumor basal cell markers such as NGFR, SOX2, ALDH1A1, and PDPN. Although mock-transfectants had only a 20% PDPN-high population, SIX1-transfectants had 60-70%. In two sets of 42 and 85 ESCC patients receiving surgery alone or neoadjuvant chemoradiotherapy followed by surgery, the cases with high SIX1 mRNA and protein expression level significantly showed a poor prognosis compared with those with low levels. These SIX1 high cases also expressed the above basal cell markers, but suppressed the differentiation markers. Finally, TGF-β signaling blockade suppressed ESCC cell growth in association with the reduction of PDPN-positive tumor basal cell population. The present results suggest that SIX1 accelerates self-renewal of tumor basal cells, resulting in a poor prognosis for ESCC patients.

Assessment of the Diagnostic Performance of Endoscopic Ultrasonography After Conventional Endoscopy for the Evaluation of Esophageal Squamous Cell Carcinoma Invasion Depth

IMPORTANCE

Distinguishing between mucosal and submucosal cancers is important for selecting the optimal treatment for patients with esophageal squamous cell carcinoma (ESCC); however, standard procedures for diagnosing cancer invasion depth have not yet been determined.

OBJECTIVE

To evaluate the diagnostic performance of endoscopic ultrasonography (EUS) after conventional endoscopy for the evaluation of ESCC invasion depth.

DESIGN, SETTING, AND PARTICIPANTS

This prospective single-arm confirmatory diagnostic study comprising 372 patients with T1 esophageal cancer was conducted at 41 secondary or tertiary hospitals in Japan. Enrollment began on July 20, 2017; patients were enrolled in 2 steps, with the first registration occurring from August 4, 2017, to December 11, 2019, and the second from August 9, 2017, to December 11, 2019. After the completion of all first and second registration examinations, patients received treatment and were followed up for 30 days, with follow-up ending on February 14, 2020. Patients were eligible for inclusion if they had pathologically or endoscopically diagnosed esophageal cancer with T1 clinical depth of invasion.

INTERVENTIONS

In the first registration, nonmagnifying endoscopy (non-ME) and magnifying endoscopy (ME) were used to diagnose cancer invasion depth. In the second registration, patients from the first registration who had cancers invading the muscularis mucosa or submucosa were enrolled and received EUS. After completion of the protocol examinations, patients received treatment with endoscopic resection or esophagectomy. The pathological results of the resected specimens were used as the reference standard for evaluating cancer invasion depth.

MAIN OUTCOMES AND MEASURES

The primary end point was the proportion of overdiagnosis of submucosal cancer (defined as invasion depth >200 μm) after receipt of non-ME and ME, with or without the addition of EUS. The secondary end points were underdiagnosis, sensitivity, and specificity.

RESULTS

Among 372 patients enrolled in the first registration, 371 received non-ME and ME. Of those, 300 patients were enrolled in the second registration, and 293 patients received EUS. A total of 269 patients (217 men [80.7%]; median age, 69 years; interquartile range, 62-75 years) were included in the final analysis. The addition of EUS was associated with a 6.6% increase in the proportion of overdiagnosis (from 16 of 74 patients [21.6%; 95% CI, 12.9%-32.7%] after non-ME and ME to 29 of 103 patients [28.2%; 95% CI, 19.7%-37.9%] after the addition of EUS; 1-sided P = .93). All subgroup analyses found similar increases in overdiagnosis of submucosal cancer. The addition of EUS was associated with a 4.5% reduction in the proportion of underdiagnosis (from 57 of 195 patients [29.2%; 95% CI, 23.0%-36.2%] after non-ME and ME to 41 of 166 patients [24.7%; 95% CI, 18.3%-32.0%] after the addition of EUS). After non-ME and ME, diagnostic sensitivity was 50.4% (95% CI, 41.0%-59.9%), specificity was 89.6% (95% CI, 83.7%-93.9%), and accuracy was 72.9% (95% CI, 67.1%-78.1%). After the addition of EUS, diagnostic sensitivity was 64.3% (95% CI, 54.9%-73.1%), specificity was 81.2% (95% CI, 74.1%-87.0%), and accuracy was 74.0% (95% CI, 68.3%-79.1%).

CONCLUSIONS AND RELEVANCE

This study found that the addition of EUS was not associated with improvements in the diagnostic accuracy of cancer invasion depth. These findings do not support the routine use of EUS after conventional endoscopy for evaluating the invasion depth among patients with T1 ESCC.

Alternative RNA products from a rice homeobox gene

Three cDNA clones were isolated from rice, OSH42, OSH44 and OSH45, which encode homeodomain sequences in the C-terminal region. The sequences of these cDNAs differ in the N- and C-termini, but they share an identical homeodomain and an acidic amino acid-rich region. The transcripts corresponding to these cDNAs are encoded by a single gene on rice chromosome 8. Differential transcription initiation results in a large transcript comprised of exons 1 and 3-7 and a smaller transcript comprised of exons 2-7. The larger transcript is constitutively expressed in all tissues tested, while the smaller transcript is expressed in leaves, stems and rachis but not in roots, flowers, or suspension callus cells. Alternative splicing also occurs at three different acceptor sites in intron 6 in all tissues tested. The GAL4 DNA-binding domain of yeast was used to study the function of various protein domains. The acidic amino acid-rich region activates the expression of a reporter gene controlled by the GAL4 target sequence, indicating that it functions as a transactivation domain. The larger transcript encodes a unique alanine and glycine-rich region on the N-terminal side of the acidic region, which is not encoded by the smaller transcript. This region completely suppresses the transactivation activity of the acidic region. This suggests that the product of the larger transcript fails to activate the expression of the target gene(s) while the product of the smaller transcript activates the expression of its target gene(s).

Comprehensive genomic profiling for patients with chemotherapy-naïve advanced cancer

Comprehensive genomic profiling (CGP) testing by next‐generation sequencing has been introduced into clinical practice as part of precision cancer medicine to select effective targeted therapies. However, whether CGP testing at the time of first‐line chemotherapy could be clinically useful is not clear. We conducted this single‐center, prospective, observational study to investigate the feasibility of CGP testing for chemotherapy‐naïve patients with stage III/IV gastrointestinal cancer, rare cancer, and cancer of unknown primary, using the FoundationOne^® companion diagnostic (F1CDx) assay. The primary outcome was the detection rate of at least one actionable/druggable cancer genomic alteration. Actionable/druggable cancer genomic alterations were determined by the F1CDx report. An institutional molecular tumor board determined the molecular‐based recommended therapies. A total of 197 patients were enrolled from October 2018 to June 2019. CGP success rate was 76.6% (151 of 197 patients), and median turnaround time was 19 days (range: 10‐329 days). Actionable and druggable cancer genomic alterations were reported in 145 (73.6%) and 124 (62.9%) patients, respectively. The highest detection rate of druggable genomic alterations in gastrointestinal cancers was 80% in colorectal cancer (48 of 60 patients). Molecular‐based recommended therapies were determined in 46 patients (23.4%). CGP testing would be a useful tool for the identification of a potentially effective first‐line chemotherapy.

Role of malate synthesis mediated by phosphoenolpyruvate carboxylase in guard cells in the regulation of stomatal movement

To clarify the pathway and role of malate synthesis in guard cells, epidermal strips isolated from Vicia faba L. leaflets were treated with 3,3-dichloro-2-dihydroxyphosphinoylmethyl-2-propenoate (DCDP), a specific inhibitor of phosphoenolpyruvate carboxylase (PEPC). When dark-closed stomata were illuminated, malate accumulated in guard cells and stomata opened; these were inhibited by 60% and 30%, respectively, by 5 mM DCDP treatment. When light-opened stomata were treated with DCDP, both malate level in guard cells and stomatal aperture decreased. Treatment with 5 mM DCDP partially inhibited CO2 incorporation into malate in guard cells. Treatment with mannitol at 0.4 M (osmotic stress) in the light increased malate level in guard cells and closed stomata. DCDP treatment decreased both malate level and stomatal aperture under stressed condition. These results show that malate synthesis in the light under both non-stressed and stressed conditions is dependent on PEPC activity. The extent of the decrease in malate level by DCDP treatment was larger under stressed condition than under nonstressed condition, suggesting that osmotic stress may enhance the activity of this pathway of malate synthesis which is induced by light. Role of malate synthesis in guard cells is discussed.

Association of local complete response with prognosis after salvage photodynamic therapy for esophageal squamous cell carcinoma

OBJECTIVES

Photodynamic therapy (PDT) is an effective salvage endoscopic treatment for local failure at the primary site after chemoradiotherapy (CRT) in esophageal cancer patients. However, the contribution of local control by salvage PDT to the prognosis is unclear. We investigated whether complete response at primary site by salvage PDT could improve the prognosis.

METHODS

Between January 2008 and March 2016, 34 patients received salvage PDT for local failure of esophageal cancer limited to stage T1-2 after definitive CRT or radiotherapy. Local complete response (L-CR) rate, adverse events, overall survival (OS), and progression-free survival (PFS) were assessed retrospectively.

RESULTS

Local complete response rates after PDT were 68% (23/34; 95% CI, 50-83%) in all patients: 81% (17/21; 95% CI, 58-95%) for stage T1 and 46% (6/13; 95% CI, 19-75%) for stage T2 patients. Grade 3 esophageal stricture occurred in one patient. The median follow-up was 26.0 months (range, 3.7-93.6 months); 21 patients died. The median survival times were 54.3 months in patients who achieved L-CR after PDT (L-CR group) and 19.8 months in those who did not (non-CR group). The 2-year OS rates were 79% (95% CI, 54-92%) in the L-CR group and 40% (95% CI, 11-68%) in the non-CR group (P = 0.0389; log-rank test). The median PFS was 21.2 months in the L-CR group and 1.9 months in the non-CR group (P < 0.001; log-rank test).

CONCLUSION

Achieving L-CR by salvage PDT for local failure after CRT in esophageal cancer was associated with good prognosis.

The conserved KNOX domain mediates specificity of tobacco KNOTTED1-type homeodomain proteins

Overproduction of the tobacco KNOTTED1-type homeodomain proteins NTH1, NTH15, and NTH23 in transgenic tobacco plants causes mild, severe, and no morphological alterations, respectively. The deduced amino acid sequences of the homeodomains and adjacent ELK domains are highly conserved, and the N-terminal KNOX domains also are moderately conserved. To investigate the contributions of both the conserved and divergent regions to the severity of morphological alterations, we generated chimeric proteins by exchanging different regions of NTH1, NTH15, and NTH23. The severity of the abnormal phenotype was dependent upon the synergistic action of both the N terminus, containing the KNOX domain, and the C terminus, containing the ELK homeodomain. Detailed analysis focusing on the C terminus revealed that the C-terminal half of the ELK domain is more effective in inducing the abnormal phenotypes than are the homeodomains. For the N terminus, severe morphological alterations were induced by exchanging a part of the KNOX domain of NTH1 with the corresponding region of NTH15. This limited region in the KNOX domain of all homeodomain proteins includes a predicted alpha-helical region, but only that in NTH15 is predicted to form a typical amphipathic structure. We discuss the possibility, based on these results, that the secondary structure of the KNOX domain is important for the induction of abnormal morphology in transgenic tobacco plants.

Timing of the infusion of nivolumab for patients with recurrent or metastatic squamous cell carcinoma of the esophagus influences its efficacy

BACKGROUND

The immune system is affected by the circadian rhythm. The objective of this study was to clarify whether time-of-day patterns (early or late in the daytime) of the infusion of nivolumab and whether its duration affect treatment efficacy in metastatic or recurrent esophageal squamous cell carcinoma (R/M-ESCC).

METHODS

The data of 62 consecutive patients with R/M-ESCC treated with nivolumab between February 2017 and May 2022 were retrospectively reviewed. The infusion of nivolumab before 13:00 was set as 'early in the day', and that after 13:00 was set as 'late in the day'. The treatment efficacy was compared between early and late groups by 3 criteria (first infusion, during the first 3 months, and all treatment courses).

RESULTS

The overall survival, progression-free survival, and response rate of patients received the first dose in the early group were significantly superior to those of patients in the late group. The progression-free survival and response rate of patients who received the majority of nivolumab infusions before 13:00 during the first 3 months were significantly superior to those who received it after 13:00, with the exception of overall survival. There were no significant differences in the overall survival, progression-free survival, and response rate between patients who received the majority of nivolumab infusions before 13:00 of all treatment courses and those who received it after 13:00.

CONCLUSION

The timing of the infusion of nivolumab may affect treatment efficacy in R/M-ESCC.

Multiple roles of single-minded 2 in esophageal squamous cell carcinoma and its clinical implications

Degree of histological differentiation is an important characteristic of cancers and may be associated with malignant potential. However, in squamous cell carcinomas, a key transcriptional factor regulating tumor differentiation is largely unknown. Chemoradiotherapy (CRT) is a standard treatment for locally advanced esophageal squamous cell carcinoma; however, the survival rate is still below 40%. From microarray data, single‐minded 2 (SIM2) was overexpressed in the epithelial subtype. Here, we investigated the correlation between SIM2 expression and its clinical implication, and in vitro and in vivo functions of SIM2 in tumor differentiation and in CRT sensitivity. Although SIM2 was suppressed in cancerous tissues, SIM2‐high ESCC showed a favorable prognosis in CRT. Transient SIM2 expression followed by 3D culture induced expression of differentiation markers and suppressed epithelial‐mesenchymal transition‐ and basal‐cell markers. Levels of PDPN‐high tumor basal cells and of expression of genes for DNA repair and antioxidant enzymes were reduced in stable transfectants, and they showed high CDDP and H₂O₂ sensitivities, and their xenografts showed a well‐differentiated histology. Reduction of tumor basal cells was restored by knockdown of aryl hydrocarbon receptor nuclear translocator (ARNT) that interacted with SIM2. Together, SIM2 increases CRT sensitivity through tumor differentiation by cooperation with ARNT.

Abnormal cell divisions in leaf primordia caused by the expression of the rice homeobox gene OSH1 lead to altered morphology of leaves in transgenic tobacco

Transgenic tobacco plants were generated carrying a rice homeobox gene, OSH1, controlled by the promoter of a gene encoding a tobacco pathogenesis-related protein (PR1a). These lines were morphologically abnormal, with wrinkled and/or lobed leaves. Histological analysis of shoot apex primordia indicates arrest of lateral leaf blade expansion, often resulting in asymmetric and anisotrophic growth of leaf blades. Other notable abnormalities included abnormal or arrested development of leaf lateral veins. Interestingly, OHS1 expression was undetectable in mature leaves with the aberrant morphological features. Thus, OSH1 expression in mature leaves is not necessary for abnormal leaf development. Northern blot and in situ hybridization analyses indicate that PR1a-OSH1 is expressed only in the shoot apical meristem and in very young leaf primordia. Therefore, the aberrant morphological features are an indirect consequence of ectopic OSH1 gene expression. The only abnormality observed in tissues expressing the transgene was periclinal (rather than anticlinal) division in mesophyll cells during leaf blade initiation. This generates thicker leaf blades and disrupts the mesophyll cell layers, from which vascular tissues differentiate. The OSH1 product appears to affect the mechanism controlling the orientation of the plane of cell division, resulting in abnormal periclinal division of mesophyll cell, which in turn results in the gross morphological abnormalities observed in the transgenic lines.

The homeobox gene NTH23 of tobacco is expressed in the basal region of leaf primordia

We reported isolation and characterization of a homeobox gene from tobacco, NTH23. The homeodomain structure of NTH23 was highly homologous to the same regions of class 2 genes of the KN1-type homeobox (sharing more than 85% amino acid identity), but was less similar to class 1 genes of KN1-type. RNA gel blot analysis revealed that NTH23 was expressed in all organs we tested although the gene is primarily expressed in young leaves. To determine more precisely the spatial expression pattern of NTH23 in tobacco, a chimeric NTH23::GUS fusion gene was introduced into tobacco. The signal of GUS activity was observed at the basal part of leaf blade primordia in the NTH23::GUS transgenic tobacco plants. This observation suggests the possibility that NTH23 may be important for the lateral growth of leaf blades.

Micronucleus test with cyclophosphamide administered by intraperitoneal injection and oral gavage

The effect of route of administration on the micronucleus test was examined in 2 laboratories: cyclophosphamide (CYP) was administered by intraperitoneal injection (i.p.) or oral gavage (p.o.) to 2 strains of mice. MS/Ae and CD-1. On the basis of a small-scale acute toxicity study and a pilot micronucleus experiment, the final micronucleus test was performed with a 48-h sampling time at doses of 25-200 mg/kg i.p. and 50-400 mg/kg p.o. CYP via the i.p. route was more toxic and induced more micronucleated polychromatic erythrocytes (MNPCEs) in MS/Ae mice than in CD-1 mice. Administration-route-related differences were not distinctly shown in the MS/Ae strain. In CD-1, however, higher doses were required for the p.o. route than for the i.p. route to induce about equal amounts of clastogenic damage.

Two types of pea leghemoglobin genes showing different O2-binding affinities and distinct patterns of spatial expression in nodules

Five distinct cDNA clones for leghemoglobin (Lb) were isolated from pea (Pisum sativum) nodules. They were classified into two groups designated PsLbA and PsLbB according to sequence homology, O(2)-binding affinities of the recombinant proteins, and in situ localization of the mRNAs. The PsLbB group was comprised of four cDNA clones: PsLb120-1, -8, -29, and -34. They showed a high similarity of deduced amino acid sequences and O(2)-binding affinities of their recombinant proteins. Among them, the spatial expression pattern of PsLb120-1 was investigated in great detail, indicating that its transcripts were localized in the region from infection zone II to the distal part of nitrogen fixation zone III in effective nodules. PsLb5-10, which is the only cDNA clone of the PsLbA type, differed considerably from the PsLbB type in amino acid sequence, and the recombinant protein had a higher O(2)-binding affinity than those of the PsLbB type. The transcripts of PsLb5-10 were detected throughout the central tissue of effective nodules. However, in ineffective nodules on the pea mutant E135 (sym13), transcripts of PsLb5-10 were restricted to the distal portion of the central tissue as well as those of PsLb120-1. These findings indicate that the pea genome contains two types of Lb genes and suggest that they have different roles in the development of nitrogen-fixing symbiosis in pea nodules.

A rare case of non-invasive ductal carcinoma of the breast coexisting with follicular lymphoma: A case report with a review of the literature

The double presentation of breast cancer and follicular lymphoma is extremely rare, and only six cases have previously been reported in the literature. In the present study, a case of synchronous ductal carcinoma in situ (DCIS) of the breast and follicular lymphoma is reported. During an annual breast screening procedure, a 49-year-old female presented with a hard induration under the nipple of the right breast and swelling of a soft lymph node (LN) in the right axilla. Mammography and ultrasonography revealed two lesions in the right breast: One was a tumor with microcalcification, 1.0 cm in diameter, and the other was a large, crude calcification, 2.5 cm in diameter. In addition, computed tomography and positron emission tomography revealed swellings of the bilateral axillary (Ax) LN and intra-abdominal para-aortic LN. The patient underwent excisions of the large calcified mass, a micro-calcified tumor and the right AxLN. The pathological and immunohistochemical studies revealed fat necrosis and DCIS of the breast, which was positive for the estrogen receptor and the progesterone receptor, while human epidermal growth factor receptor II protein expression was evaluated as 2+ and stage was classified as pTis pN0 M0, stage 0. Furthermore, the Ax node was diagnosed as follicular lymphoma, which was positive for cluster of differentiation (CD)20, CD79a, CD10 and B-cell lymphoma (Bcl)-2 protein, but negative for Bcl-6 protein. The clinical stage was classified as stage III. The patient was administered chemotherapy followed by radiotherapy to the conserved breast. Two years have passed since the surgery, and the patient is disease-free.

Expression of rice OSH1 gene is localized in developing vascular strands and its ectopic expression in transgenic rice causes altered morphology of leaf

Transgenic rice plants (Oryza sativa cv. Nipponbare) carrying 1 or 2 copies of a rice homeobox gene, OSH1, under the control of the CaMV 35S promoter were generated. The transgene caused altered morphology of leaf, such as ligule-replacement and abnormal division of sclerenchyma cells. The phenotype of these leaves resembles that of maize leaf morphological mutant, Knotted 1, which is caused by duplication of the KN1 gene (Veit et al., 1990). The in situ hybridization analysis has revealed that the expression of endogenous OSH1 is mainly localized in developing vascular strands of stem. We have discussed the biological roles of OSH1 in rice based on these results.

Transgenic tobacco over-expressing a homeobox gene shows a developmental interaction between leaf morphogenesis and phyllotaxy

The tobacco gene, NTH1, encodes a polypeptide of 326 amino acids and is a member of the class1 KN1-type family of homeobox genes. Expression of NTH1 has mainly been observed in vegetative and reproductive shoot apices, not observed in roots or expanded leaves. Over-expression of NTH1 in transgenic plants caused abnormal leaf morphology, consisting of wrinkling and curvature. Interestingly, the direction of leaf curvature tended to be conserved among almost all of the leaves in any given transformant. In transgenic plants exhibiting clockwise or anticlockwise phyllotaxy, leaves curved to the right or left, respectively, when looking from the shoot apex toward the base. Micro-surgical experiments demonstrated that the presence of the shoot apex is necessary for the development of leaf curvature, indicating that the order of formation of leaves on the stem (the generative spiral) affects leaf development. We found a correlation between the severity of leaf curvature and the value of the plastochron ratio, a parameter of phyllotaxy. Transformants with more severe phenotypes had larger plastochron ratios. From these findings, we discuss the possibility that an increase in the plastochron ratio, caused by over-expression of NTH1 in the shoot apex, may be involved in leaf curvature.

Expression of nodulin genes in plant-determined ineffective nodules of pea

The mutant E135 (sym 13) of pea (Pisum sativum L.) forms a normal number of small white nodules that contain bacteroids, but these bacteroids lack nitrogenase activity. To evaluate the effects of the sym 13 gene on the expression of nodulin genes, cDNA clones for nodulins were isolated from pea nodules and the expression of nodulin genes in ineffective E135 nodules was compared with that in nitrogen-fixing nodules on the wild-type parent, cv. Sparkle. Nineteen cDNA clones for nodulins, including ENOD2 and cDNAs for two distinct leghemoglobins (Lbs), were isolated from Sparkle nodules by a subtractive hybridization procedure. All the nodulin genes examined were expressed in nodules on both E135 and Sparkle plants. However, the level of expression of seven genes, one of which was an Lb gene that corresponded to PsN5, was significantly lower in E135 nodules. The levels of Lb apo-proteins, with the exception of Lb-III and Lb-IV, in E135 nodules resembled those in Sparkle nodules, but the level of heme in E135 nodules was lower than that in Sparkle nodules. Although the expression of the two Lb genes that corresponded to PsN5 and PsN120 in E135 nodules was slightly depressed by exogenous ammonia, the level of the PsN5 transcript was still lower than the control level in Sparkle nodules. Our results indicate that the plant gene sym 13 does not influence the induction of nodulin genes but does influence the level of the expression of some genes, one of which is a gene for Lb, as well as the level of heme.

Technical considerations for analyzing EMT-MET data from surgical samples

With an increase of neoadjuvant therapy, biopsy samples have become imperative for cancer research; however, what kind of difference between surgical and endoscopic biopsy samples in gene expression profiles was still unclear. Recently, we reported artificially induced epithelial-mesenchymal transition (aiEMT) in the surgical samples by comparison between gene expression profiles of both samples of the esophagus. This was also found in mouse epithelium under an ischemic condition for 4h. This study will evoke underestimation of the prognostic evaluation power of EMT related markers in past cancer research and prevalence of biopsy samples for in vivo expression profiling with low biases.