Distribution and co-localization of diversified natriuretic peptides in the eel heart.

Atrial and B-type natriuretic peptides (ANP and BNP) are cardiac hormones important for cardiovascular and body fluid regulation. In some teleost species, an additional member of the natriuretic peptide family, ventricular NP (VNP), has been identified. In this study, we examine tissue distribution of these three NPs in the eel heart. Quantitative real-time PCR showed that anp is almost exclusively expressed in atria, bnp equally in atria and ventricles and vnp three-fold more in ventricles than in atria. The amount of bnp transcript overall in the heart was 1/10 those of anp and vnp. There was no difference in transcript levels between freshwater and seawater-acclimated fishes. Immunohistochemistry using specific antisera and in situ hybridization using gene-specific probes showed that NP signals were detected in most atrial and ventricular myocytes with some regional differences in density. Because of high sequence similarity of the three NPs, each of the three NP antisera individually was pre-incubated with 10-8 M of the other two non-targeted cardiac NPs to increase the specificity. A few atrial myocytes contained all three NPs in the same cell. Immuno-electron microscopy identified many dense-core vesicles containing ANP in atria and VNP in ventricles and some vesicles contained both ANP and VNP as demonstrated using pre-absorbed antisera. Based on these data and those of previous studies, we suggest that in eels ANP is secreted from atria in a regulatory pathway and VNP from ventricles in a constitutive pathway. In addition, VNP, not BNP, is the principal ventricular hormone in eels.

Extracorporeal shock wave treatment can selectively destroy end plates in neuromuscular junctions.

INTRODUCTION: This study assesses the effect of radial extracorporeal shock wave (rESW) exposure on neuromuscular transmission and neuromuscular junction (NMJ) morphology. METHODS: We applied 2,000 rESWs at 0.18 mJ/mm2 and a frequency of 15 Hz to the right calf of male rats, measured the compound muscle action potential (CMAP), and examined NMJ morphology using electron microscopy. Left calf muscles were used as controls. RESULTS: rESW exposure significantly reduced CMAP amplitude without delayed latency in exposed muscles compared with controls. All rESW-exposed muscles exhibited NMJs with irregular end plates. Mean interjunctional fold interval was significantly increased compared with controls. However, axon terminals and muscle fibers surrounding NMJs with irregular end plates were unchanged. DISCUSSION: This localized destruction of end plates may be caused by differences in acoustic impedance induced by the density of acetylcholine receptors. These results provide a possible mechanism for the effectiveness of rESW treatment for spasticity and dystonia. Muscle Nerve 57: 466-472, 2018.

Tumor-infiltrating CD8+ and FOXP3+ lymphocytes in triple-negative breast cancer: its correlation with pathological complete response to neoadjuvant chemotherapy.

The anti-tumor immune response was recently reported to play a critical role in the chemotherapeutic sensitivity of breast cancer. Therefore, we investigated the correlation between CD8+ and FOXP3+ tumor-infiltrating lymphocytes and the pathological complete response (pCR) following neoadjuvant chemotherapy (NAC) in triple-negative breast cancer (TNBC), in conjunction with neoangiogenesis, basal and proliferation markers. CD8+ and FOXP3+ lymphocytes were assessed in biopsy specimens by double-staining immunohistochemistry, in combination with immunostaining of vasohibin-1, CD31, EGFR, CK5/6, and Ki-67. Earlier age, pre-menopausal status, smaller tumor size, and high Ki-67 were significantly associated with pCR, as in high CD8+, high CD8+/FOXP3+ ratio, and low vasohibin-1 positive ratio. Multivariate analysis did reveal that a high CD8+/FOXP3+ ratio was a strong predictor of pCR with an odds ratio of 5.32 (P = 0.005). High Ki-67 was also significantly associated with pCR (P = 0.002). TNBCs with a high CD8+/FOXP3+ ratio and high Ki-67 had the highest pCR rate (70%) following NAC. However, the pCR rate of the patients with low CD8+/FOXP3+ ratio and low Ki-67 was only 5%. The pCR rates of a high CD8+/FOXP3+ ratio and low Ki-67 patients and those with a low CD8+/FOXP3+ ratio and high Ki-67 were 24 and 21%, respectively. TNBCs with a high CD8+/FOXP3+ ratio were more sensitive to anthracycline and taxane-based chemotherapeutic regimens, and the CD8+/FOXP3+ ratio in conjunction with Ki-67 could predict pCR following NAC in TNBC. This predictor may represent a new surrogate for testing the efficacy of investigational agents in the neoadjuvant setting.

Androgenic pathways in the progression of triple-negative breast carcinoma: a comparison between aggressive and non-aggressive subtypes.

One of the active intracellular pathways/networks in triple-negative breast carcinoma (TNBC) is that of the androgen receptor (AR). In this study, we examined AR and androgen-metabolising enzyme immunoreactivity in subcategories of TNBC to further elucidate the roles of androgenic pathways in TNBC. We utilised formalin-fixed paraffin-embedded breast cancer samples from ductal carcinoma in situ (DCIS) and invasive ductal carcinoma patient cohorts. We then used immunohistochemistry to classify these samples into basal-like and non-basal samples and to assess interactions between AR, androgen-metabolising enzymes and proliferation. To further substantiate our hypothesis and provide mechanistic insights, we also looked at the expression and regulation of these factors in publically available microarray data and in a panel of TNBC AR-positive cell lines. DCIS was associated with higher levels of AR and enzymes (p < 0.02), although a similar difference was not noticed in basal and non-basal samples. AR and enzymes were correlated in all states. In TNBC cell lines (MDA-MD-453, MFM-223 and SUM185-PE), we found that DHT treatment up-regulated 5αR1 and 17ßHSD5 suggesting a mechanistic explanation for the correlations observed in the histological samples. Publicly available microarray data in TNBC cases suggested similar patterns to those observed in histological samples. In the majority of settings, including publically available microarray data, an inverse association between AR and proliferation was detected. These findings suggest that decreases in AR and androgen-metabolising enzymes may be involved in the increased biological aggressiveness in TNBC development.

Androgenic pathway in triple negative invasive ductal tumors: its correlation with tumor cell proliferation.

Triple negative breast cancer (TNBC) is defined by estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 negativity. Patients with TNBC frequently undergo an aggressive clinical course due to the unavailability of specific targeted therapies. Androgen receptor (AR) was reported to be expressed in up to 60% of TNBC cases but there have been controversies as to the roles of androgen signaling through AR in TNBC. Therefore, in this study, we analyzed the status of AR in combination with androgen synthesizing enzymes (5α-reductase type 1 (5αR1) and 17ß-hydroxysteroid dehydrogenase type 5 (17ßHSD5)] in order to further understand androgenic actions in TNBC. Androgen receptor, 5αR1, and 17ßHSD5 were immunolocalized in a cohort of 203 TNBC patients from Thailand and Japan. We then correlated the findings with clinicopathological characteristics (age, stage, tumor diameter, lymph node invasion, metastatic spread, Ki-67 labeling index, disease-free survival, and overall survival) of the patients. Univariate analysis revealed that AR+/enzyme+ cases were associated with a significantly lower Ki-67 labeling index than AR-/enzyme- samples. Multivariate analysis indicated the presence of significant positive correlations between AR and enzyme status in tumor cells, and between tumor diameter, lymph node invasion, and distant metastasis. Significant negative correlations were also detected between Ki-67 labeling index and AR status (P = 0.04) or 5αR1 (P < 0.001). Cox proportional hazards analysis showed that Ki-67 labeling index and stage were the only factors predicting disease-free and overall survival of the patients, although univariate Kaplan-Meier analysis revealed AR/5αR1 negativity suggested a more adverse clinical course up to 80 months after surgery. These results suggest that the presence of androgen synthesizing pathways in addition to AR expression in tumor cells could confer a better clinical outcome through suppression of cell proliferation.

Hes1 is required for the development of pharyngeal organs and survival of neural crest-derived mesenchymal cells in pharyngeal arches.

Hes genes are required to maintain diverse progenitor cell populations during embryonic development. Loss of Hes1 results in a spectrum of malformations of pharyngeal endoderm-derived organs, including the ultimobranchial body (progenitor of C cells), parathyroid, thymus and thyroid glands, together with highly penetrant C-cell aplasia (81%) and parathyroid aplasia (28%). The hypoplastic parathyroid and thymus are mostly located around the pharyngeal cavity, even at embryonic day (E) 15.5 to E18.5, indicating the failure of migration of the organs. To clarify the relationship between these phenotypes and neural crest cells, we examine fate mapping of neural crest cells colonized in pharyngeal arches in Hes1 null mutants by using the Wnt1-Cre/R26R reporter system. In null mutants, the number of neural crest cells labeled by X-gal staining is markedly decreased in the pharyngeal mesenchyme at E12.5 when the primordia of the thymus, parathyroid and ultimobranchial body migrate toward their destinations. Furthermore, phospho-Histone-H3-positive proliferating cells are reduced in number in the pharyngeal mesenchyme at this stage. Our data indicate that the development of pharyngeal organs and survival of neural-crest-derived mesenchyme in pharyngeal arches are critically dependent on Hes1. We propose that the defective survival of neural-crest-derived mesenchymal cells in pharyngeal arches directly or indirectly leads to deficiencies of pharyngeal organs.

Hes1 is required for the development of the superior cervical ganglion of sympathetic trunk and the carotid body.

Hes1 gene represses the expression of proneural basic helix-loop-helix (bHLH) factor Mash1, which is essential for the differentiation of the sympathetic ganglia and carotid body glomus cells. The sympathetic ganglia, carotid body, and common carotid artery in Wnt1-Cre/R26R double transgenic mice were intensely labeled by X-gal staining, i.e., the neural crest origin. The deficiency of Hes1 caused severe hypoplasia of the superior cervical ganglion (SCG). At embryonic day (E) 17.5-E18.5, the volume of the SCG in Hes1 null mutants was reduced to 26.4% of the value in wild-type mice. In 4 of 30 cases (13.3%), the common carotid artery derived from the third arch artery was absent in the null mutants, and the carotid body was not formed. When the common carotid artery was retained, the organ grew in the wall of the third arch artery and glomus cell precursors were provided from the SCG in the null mutants as well as in wild-types. However, the volume of carotid body in the null mutants was only 52.5% of the value in wild-types at E17.5-E18.5. These results suggest that Hes1 plays a critical role in regulating the development of neural crest derivatives in the mouse cervical region.

The atypical Guanine-nucleotide exchange factor, dock7, negatively regulates schwann cell differentiation and myelination.

In development of the peripheral nervous system, Schwann cells proliferate, migrate, and ultimately differentiate to form myelin sheath. In all of the myelination stages, Schwann cells continuously undergo morphological changes; however, little is known about their underlying molecular mechanisms. We previously cloned the dock7 gene encoding the atypical Rho family guanine-nucleotide exchange factor (GEF) and reported the positive role of Dock7, the target Rho GTPases Rac/Cdc42, and the downstream c-Jun N-terminal kinase in Schwann cell migration (Yamauchi et al., 2008). We investigated the role of Dock7 in Schwann cell differentiation and myelination. Knockdown of Dock7 by the specific small interfering (si)RNA in primary Schwann cells promotes dibutyryl cAMP-induced morphological differentiation, indicating the negative role of Dock7 in Schwann cell differentiation. It also results in a shorter duration of activation of Rac/Cdc42 and JNK, which is the negative regulator of myelination, and the earlier activation of Rho and Rho-kinase, which is the positive regulator of myelination. To obtain the in vivo evidence, we generated Dock7 short hairpin (sh)RNA transgenic mice. They exhibited a decreased expression of Dock7 in the sciatic nerves and enhanced myelin thickness, consistent with in vitro observation. The effects of the in vivo knockdown on the signals to Rho GTPases are similar to those of the in vitro knockdown. Collectively, the signaling through Dock7 negatively regulates Schwann cell differentiation and the onset of myelination, demonstrating the unexpected role of Dock7 in the interplay between Schwann cell migration and myelination.

Repeated freeze-thaw cycles reduce the survival rate of osteocytes in bone-tendon constructs without affecting the mechanical properties of tendons.

Frozen bone-patellar tendon bone allografts are useful in anterior cruciate ligament reconstruction as the freezing procedure kills tissue cells, thereby reducing immunogenicity of the grafts. However, a small portion of cells in human femoral heads treated by standard bone-bank freezing procedures survive, thus limiting the effectiveness of allografts. Here, we characterized the survival rates and mechanisms of cells isolated from rat bones and tendons that were subjected to freeze-thaw treatments, and evaluated the influence of these treatments on the mechanical properties of tendons. After a single freeze-thaw cycle, most cells isolated from frozen bone appeared morphologically as osteocytes and expressed both osteoblast- and osteocyte-related genes. Transmission electron microscopic observation of frozen cells using freeze-substitution revealed that a small number of osteocytes maintained large nuclei with intact double membranes, indicating that these osteocytes in bone matrix were resistant to ice crystal formation. We found that tendon cells were completely killed by a single freeze-thaw cycle, whereas bone cells exhibited a relatively high survival rate, although survival was significantly reduced after three freeze-thaw cycles. In patella tendons, the ultimate stress, Young's modulus, and strain at failure showed no significant differences between untreated tendons and those subjected to five freeze-thaw cycles. In conclusion, we identified that cells surviving after freeze-thaw treatment of rat bones were predominantly osteocytes. We propose that repeated freeze-thaw cycles could be applied for processing bone-tendon constructs prior to grafting as the treatment did not affect the mechanical property of tendons and drastically reduced surviving osteocytes, thereby potentially decreasing allograft immunogenecity.

A case of strongly suspected Lynch syndrome with colorectal neuroendocrine carcinoma.

BACKGROUND: Neuroendocrine cell carcinomas (NEC) of the colon and rectum are uncommon, representing ~ 0.1% of all colorectal carcinomas. They are associated with a much worse prognosis compared to adenocarcinoma of the colon and rectum, as death occurs in approximately half of all patients within 1 year. Lynch syndrome (LS) is the most common cause of inherited colorectal cancer, accounting for 2-4% of newly diagnosed colorectal cancer cases. This case is extremely rare which was strongly suspected LS as the background, and NEC as the histological type of colorectal cancer. CASE PRESENTATION: The patient was a 44-year-old man presenting with vomiting as the main complaint. He had undergone ileocecal resection for cecal cancer at age 29. The diagnosis was obstructive descending colorectal cancer, and colonoscopy revealed tumors in the rectum and sigmoid colon in addition. Due to multiple occurrences of colorectal cancer and its prevalence in the patient's family, LS was suspected. The operation which was a subtotal proctocolectomy was performed. Pathological analysis revealed complete curative resection and the descending colon cancer of the obstructed portion was at the most advanced pathological Stage IIIC in UICC TNM classification, and the tissue type was a NEC. The Ki-67 index was 70%. The results of the microsatellite instability (MSI) test showed high-frequency MSI. The BRAF V600E variant was negative. The immunoexpression of MLH1 was positive, MSH2 was negative, PMS2 was positive, and MSH6 was negative. CONCLUSIONS: Extended surgery is recommended for incipient colorectal cancer in LS cases in order to reliably reduce the risk of developing metachronous colorectal cancer. The survival outcome of surgery alone on digestive tract NECs, even locoregional lesions that are completely resection, is extremely poor. It is currently unclear if digestive tract NECs develop more readily in patients with LS. The accumulation of additional cases is necessary.

SEM observation of wet biological specimens pretreated with room-temperature ionic liquid.

A facile pretreatment process for SEM: The use of room temperature ionic liquids (RTILs) provides an interesting method for SEM of biological specimens. We used a novel and concise method of pretreatment, excluding fixation or Au sputtering steps. Fine and smooth-textured SEM images of a wide variety of biological specimens treated in this way were observed without artefacts.

Natural Killer Cell Group 7 Sequence in Cytotoxic Cells Optimizes Exocytosis of Lytic Granules Essential for the Perforin-Dependent, but Not Fas Ligand-Dependent, Cytolytic Pathway.

Cytotoxic cells, such as CD8+ T cells or NK cells, have been shown to eliminate virus-infected cells or transformed cells primarily via two pathways: the perforin/granzyme-dependent pathway and the Fas ligand-Fas pathway; however, the precise cytolytic mechanisms have not been clarified thoroughly. In our previous study, we demonstrated that a T-box transcription factor, Eomesodermin (Eomes), may play important roles in activating the perforin pathway besides inducing perforin and granzyme B mRNA expression. In this study, we identified natural killer cell group 7 sequence (Nkg7), a molecule induced by Eomes, to be found critical for perforin-dependent cytolysis. Nkg7 mRNA expression in leukocytes from normal mice was mainly restricted to cells with cytotoxicity such as NK cells, NKT cells, and activated CD8+ T cells. The cytolytic activity of NK cells or CD8+ CTLs from Nkg7-deficient mice against Fas-negative target cells was reduced significantly, whereas Fas ligand-mediated cytolysis by Nkg7-deficient CTLs was not impaired. Further, translocation of granule membrane protein CD107a to the cell surface upon CD3 stimulation was defective in CD8+ CTLs from Nkg7 knockout, whereas surface induction of another granule membrane protein, CD63, was almost normal. In addition, analyses of lytic granules in CTLs by electron microscopy revealed that the number of lytic granules with dense cores was significantly reduced in Nkg7-knockout CTLs. These results indicate that Nkg7 may specifically contribute to efficient cytolysis via the perforin/granzyme pathway by enhancing the exocytosis of a particular type of lytic granules.

A randomized, double-blind, phase II study of oral histone deacetylase inhibitor resminostat plus S-1 versus placebo plus S-1 in biliary tract cancers previously treated with gemcitabine plus platinum-based chemotherapy.

PURPOSE: Effective second-line chemotherapy options are limited in treating advanced biliary tract cancers (BTCs). Resminostat is an oral histone deacetylase inhibitor. Such inhibitors increase sensitivity to fluorouracil, the active form of S-1. In the phase I study, addition of resminostat to S-1 was suggested to have promising efficacy for pre-treated BTCs. This study investigated the efficacy and safety of resminostat plus S-1 in second-line therapy for BTCs. METHODS: Patients were randomly assigned to receive resminostat or placebo (200 mg orally per day; days 1-5 and 8-12) and S-1 group (80-120 mg orally per day by body surface area; days 1-14) over a 21-day cycle. The primary endpoint was progression-free survival (PFS). Secondary endpoints comprised overall survival (OS), response rate (RR), disease control rate (DCR), and safety. RESULTS: Among 101 patients enrolled, 50 received resminostat+S-1 and 51 received placebo+S-1. Median PFS was 2.9 months for resminostat+S-1 vs. 3.0 months for placebo+S-1 (HR: 1.154, 95% CI: 0.759-1.757, p = 0.502); median OS was 7.8 months vs. 7.5 months, respectively (HR: 1.049, 95% CI: 0.653-1.684, p = 0.834); the RR and DCR were 6.0% vs. 9.8% and 70.0% vs. 78.4%, respectively. Treatment-related adverse events (TrAEs) of grade ≥ 3 occurring more frequently (≥10% difference) in the resminostat+S-1 than in the placebo+S-1 comprised platelet count decreased (18.0% vs. 2.0%) and decreased appetite (16.0% vs. 2.0%). CONCLUSIONS: Resminostat plus S-1 therapy improved neither PFS nor OS for patients with pre-treated BTCs. Addition of resminostat to S-1 was associated with higher incidence of TrAEs, but these were manageable (JapicCTI-183883).

Polyglycolic acid-collagen tube combined with collagen-binding basic fibroblast growth factor accelerates gait recovery in a rat sciatic nerve critical-size defect model.

Several nerve conduits have been investigated for their potential as alternative sources of autografts for bridging neural gaps. However, autologous nerve transplants remain the most effective for nerve repair. We examined clinically approved nerve conduits containing collagen and polyglycolic acid (PGA-c) combined with collagen-binding basic fibroblast growth factor (bFGF) containing a polycystic kidney disease (PKD) domain and collagen binding domain (CBD) (bFGF-PKD-CBD) in a rat 15-mm sciatic nerve critical-size defect model. The treatment groups were: PGA-c immersed in phosphate-buffered saline (PBS) (PGA-c/PBS group), bFGF (PGA-c/bFGF group), or bFGF-PKD-CBD (PGA-c/bFGF-PKD-CBD group), and no treatment (Defect group). Gait and histological analyses were performed. Four weeks after treatment, the recovery rate of the paw print area was significantly greater in the PGA-c/bFGFPKD-CBD group than the PGA-c/PBS and PGA-c/bFGF groups. Mean intensity of paw prints was significantly greater in the PGA-c/bFGF-PKD-CBD group than the PGA-c/PBS and Defect groups. Swing time was significantly greater in the PGA-c/PBS, PGA-c/bFGF, and PGA-c/bFGF-PKD-CBD groups than the Defect group. At 8 weeks, all three parameters were significantly greater in the PGA-c/PBS, PGA-c/bFGF, and PGA-c/bFGF-PKD-CBD groups than the Defect group. Regenerated myelinated fibers were observed in 7/8 (87.5%) rats in the PGA-c/bFGF-PKD-CBD group after 8 weeks, and in 1/8 (12.5%) and 3/8 (37.5%) rats in the PGA-c/PBS and PGA-c/bFGF groups, respectively. PGA-c/bFGF-PKD-CBD composites may be promising biomaterials for promoting functional recovery of long-distance peripheral nerve defects in clinical practice.

The effect of cryopreservation or heating on the mechanical properties and histomorphology of rat bone-patellar tendon-bone.

The effects of cryopreservation on tendon allograft have been reported, but remain unclear, particularly the potential effects on mechanical properties and histological changes by ice crystal formation. There are also few studies about effects of heating for sterilization of tendon. We evaluated the effect of cryopreservation or heating on the mechanical properties and histomorphology of rat bone-patellar tendon-bones (BTBs). BTBs were processed by cryopreservation at -80 degrees C for 3 weeks, or heating at 80 degrees C for 10 min. Tensile testing and histomorphological examination were performed. The cryopreservation of tendons showed less influences on their mechanical properties. When cryopreserved BTBs in frozen state were fixed by freeze-substitution method, many spaces were observed in interfibrillar substances. These results suggest that the collagen fibers of cryopreserved tendons were histomorphologically affected by ice crystals. The heating of tendons completely destroyed the collagen fibers of the tendons and is therefore thought to be inappropriate for the sterilization of BTBs.

Oriented collagen tubes combined with basic fibroblast growth factor promote peripheral nerve regeneration in a 15 mm sciatic nerve defect rat model.

We developed a new scaffold material-oriented collagen tubes (OCT)-and evaluated the potential of OCTs combined with basic fibroblast growth factor (bFGF) to repair of a 15 mm sciatic nerve defect in rats. The treatment groups consisted of OCT with adsorbed bFGF (OCT/bFGF group), OCT in phosphate-buffered saline (PBS) (OCT/PBS group), and a no-treatment group (Defect group). Functional evaluation of nerve regeneration was performed using the CatWalk system, and histological analyses of the defect sites were also performed. In rats treated with either OCT/bFGF or OCT/PBS, the walking function parameter of max contact area returned to normal levels by 4 weeks after grafting, and the regeneration of myelinated fibers was detected after 8 weeks. However, more regenerated myelinated fibers were observed in the OCT/bFGF group compared with the OCT/PBS group at 4 weeks. In addition, the max contact area and swing speed in the OCT/bFGF group were significantly recovered compared to the OCT/PBS and Defect groups at 8 weeks. Although the combination of bFGF and OCT was superior to OCT alone for nerve regeneration and functional recovery, the present findings demonstrate that OCT alone or in combination with bFGF accelerates nerve repair in a large peripheral nerve defect in rats. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 8-14, 2017.

Vitamin A Inhibits Development of Dextran Sulfate Sodium-Induced Colitis and Colon Cancer in a Mouse Model.

Vitamin A is essential to mucosal immunity and cell differentiation. The fact that lack of it might involve chronic inflammation and increased risk of cancer has been reported. Little is known about the mechanism of vitamin A deficiency in the development of colitis and its influence on development of colorectal cancer. To determine the influence of vitamin A deficiency on colitis and colorectal cancer development, an experimental study using a colitis mouse model was performed. Dextran sulfate sodium (DSS) colitis was induced in vitamin A-deficient and vitamin A-supplemented mice. Further, colorectal carcinoma was induced by a combination of azoxymethane preinjection and DSS colitis. Results were compared between the two groups mainly by immunohistochemical analysis. Colitis was more severe and recovery from colitis was slower in vitamin A-deficient mice than in vitamin A-supplemented mice. Compared with vitamin A-supplemented mice, vitamin A-deficient mice had decreases in colonic subepithelial myofibroblasts and the ratio of mucosal IgA(+)/IgG(+) cells, increases in CD11c(+) dendritic cells, and a higher rate of development of colorectal carcinoma with colitis following azoxymethane. Vitamin A lipid droplets in subepithelial myofibroblasts were decreased in vitamin A-deficient mice, suggesting alterations in colonic crypt niche function. Thus, vitamin A inhibited colitis and the development of colorectal cancer.

Identification of a chromosomal breakpoint and detection of a novel form of an MLL-AF17 fusion transcript in acute monocytic leukemia with t(11;17)(q23;q21).

More than 40 genes have been reported as translocation partners of the mixed lineage leukemia gene (MLL) in hematologic malignancies. AF17 was identified earlier than most other MLL translocation partners. On the other hand, there is only 1 report of an MLL-AF17 fusion transcript in acute myeloid leukemia (AML). Here we describe a 40-year-old man with a diagnosis of AML involving t(11;17)(q23;q21). We identified a chromosomal breakpoint for t(11;17)(q23;q21) at MLL intron 6 and AF17 intron 8. Although the previously reported form of the MLL-AF17 fusion transcript was not detected by reverse transcriptase-polymerase chain reaction (PCR) analysis, a novel form of an MLL-AF17 fusion transcript joining MLL exon 6 to AF17 exon 9 was detected by complementary DNA panhandle PCR. The fact that 2 forms of MLL-AF17 retain the leucine zipper domain of AF17 suggests that the dimerization domain of AF17 is critical for leukemogenesis by the MLL-AF17 fusion gene.