Fusobacterium nucleatum confers chemoresistance by modulating autophagy in oesophageal squamous cell carcinoma

Background Fusobacterium nucleatum (F. nucleatum) is a gut microbe implicated in gastrointestinal tumorigenesis. Predicting the chemotherapeutic response is critical to developing personalised therapeutic strategies for oesophageal cancer patients. The present study investigated the relationship between F. nucleatum and chemotherapeutic resistance in oesophageal squamous cell carcinoma (ESCC).Methods We examined the relationship between F. nucleatum and chemotherapy response in 120 ESCC resected specimens and 30 pre-treatment biopsy specimens. In vitro studies using ESCC cell lines and co-culture assays further uncovered the mechanism underlying chemotherapeutic resistance.Results ESCC patients with F. nucleatum infection displayed lesser chemotherapeutic response. The infiltration and subsistence of F. nucleatum in the ESCC cells were observed by transmission electron microscopy and laser scanning confocal microscopy. We also observed that F. nucleatum modulates the endogenous LC3 and ATG7 expression, as well as autophagosome formation to induce chemoresistance against 5-FU, CDDP, and Docetaxel. ATG7 knockdown resulted in reversal of F. nucleatum-induced chemoresistance. In addition, immunohistochemical studies confirmed the correlation between F. nucleatum infection and ATG7 expression in 284 ESCC specimens.Conclusions F. nucleatum confers chemoresistance to ESCC cells by modulating autophagy. These findings suggest that targeting F. nucleatum, during chemotherapy, could result in variable therapeutic outcomes for ESCC patients.Subject terms: Tumour biomarkers, Oesophageal cancer     

Evaluation of beam hardening and photon scatter by brass compensator for IMRT

When a brass compensator is set in a treatment beam, beam hardening may take place. This variation of the energy spectrum may affect the accuracy of dose calculation by a treatment planning system and the results of dose measurement of brass compensator intensity modulated radiation therapy (IMRT). In addition, when X-rays pass the compensator, scattered photons are generated within the compensator. Scattered photons may affect the monitor unit (MU) calculation. In this study, to evaluate the variation of dose distribution by the compensator, dose distribution was measured and energy spectrum was simulated using the Monte Carlo method. To investigate the influence of beam hardening for dose measurement using an ionization chamber, the beam quality correction factor was determined. Moreover, to clarify the effect of scattered photons generated within the compensator for the MU calculation, the head scatter factor was measured and energy spectrum analyses were performed. As a result, when X-rays passed the brass compensator, beam hardening occurred and dose distribution was varied. The variation of dose distribution and energy spectrum was larger with decreasing field size. This means that energy spectrum should be reproduced correctly to obtain high accuracy of dose calculation for the compensator IMRT. On the other hand, the influence of beam hardening on k_Q was insignificant. Furthermore, scattered photons were generated within the compensator, and scattered photons affect the head scatter factor. These results show that scattered photons must be taken into account for MU calculation for brass compensator IMRT.     

Sudden Onset of Platypnea-Orthodeoxia Syndrome Caused by Traumatic Tricuspid Regurgitation With Ruptured Chordae Tendineae After Blunt Chest Trauma

An 86-year-old man was admitted our hospital because of sudden onset of dyspnea after blunt chest trauma. Because his oxygen saturation deteriorated from 92% in the supine position to 86% in the sitting position, platypnea-orthodeoxia syndrome was suspected. Transesophageal echocardiography showed severe tricuspid regurgitation (TR) caused by anterior papillary muscle rupture. Furthermore, right-to-left shunt with TR through a patent foramen ovale (PFO) was observed. The diagnosis was therefore platypnea-orthodeoxia syndrome with right-to-left shunt through PFO with shunting exacerbated by acute severe TR after blunt chest trauma. The patient underwent urgent tricuspid valve repair and PFO closure and has remained asymptomatic postoperatively.     

Development of packaging cell lines for generation of adeno-associated virus vectors by lentiviral gene transfer of trans-complementary components

Adeno-associated virus (AAV) vector system has several useful advantages with regard to in vitro and in vivo gene transfer. However, their usages have been limited by cumbersome and labor-intensive vector production in the traditional method. To overcome limitations in AAV production, in this report, we explored the possibility of generating AAV packaging cell line, 293T R/C.VA.E2A.E4. cells, by using lentivirus-mediated transduction of Rep/Cap gene of AAV-2, VA RNA, E2A, and E4 genes of Ad5 into 293T cells. In packaging cell lines, it is important that supply of the AAV vector can be stably performed for long time. We showed that the 293T R/C.VA.E2A.E4. cells have stably maintained the transduced components after more than 10 passages and yielded high-titer AAV vectors, and the titer of AAV vectors did not decline even if culture of the packaging cells was continued for long time. The Rep/Cap and E4 gene products caused no remarkable cytotoxicity. The 293T R/C.VA.E2A.E4. cells might be able to tolerate the Rep/Cap and E4 gene products, or have less copy numbers of the Rep/Cap and E4 genes than the traditional method. Moreover, we showed that the AAV vectors derived from 293T R/C.VA.E2A.E4. cells infected the primary human CD34+ haematopoietic progenitor cells with high efficiency (50-70%). In the 293T R/C.VA.E2A.E4. cells, the AAV vectors can be generated by the transfection of one AAV vector plasmid, and large-scale AAV production can be easily achieved. It is important that cumbersome, variable, and costly transfection is avoided.     

Deleted HTLV provirus in peripheral blood cells of a patient with T-cell prolymphocytic leukaemia

We describe the first case of T-cell prolymphocytic leukaemia (T-PLL) in which the peripheral blood cells contained a human T-lymphotropic virus (HTLV) related tax sequence. Serum screening tests for anti-HTLV-I/II antibodies were negative. Polymerase chain reaction disclosed the presence of an HTLV-I tax sequence in the peripheral blood. Other sets of oligonucleotide primers for HTLV-I gag , pol , env and the long terminal repeat regions and for the HTLV-II pol region were negative in the DNA of the cells. Although patients with T-PLL have been reported to be seronegative for HTLV-I, our findings point to the possibility that HTLV-I infection might be involved in the aetiology of at least some cases of T-PLL and that there may be alternative mechanisms involved in HTLV-associated leukaemogenesis.     

Mycobacteria in the Intestine of Japanese Patients with Inflammatory Bowel Disease

Objectives : It is still controversial whether or not a mycobacterial infection may be a cause of Crohn's disease. Mycobaclerium paratuberculosis may be very difficult to detect using routine culture techniques. To clarify this, we delected mycobacterial DNA in patients with inflammatory bowel disease. Methods : IS900 sequences highly specific to M. paratuberculosis and groEL gene encoding a conserved mycobacterial antigen were studied in colonic mucosa using polymerase chain reaction (PCR). PCR products were analyzed by Southern blot hybridization. Results : IS900 sequences were detected in all (100%)of 10 patients with Crohan's disease, in 11 (61.1%) of 18 patients with ulcerative colitis, and in 14 (87.5%) of 16 control patients with noninflammatory bowel disease. All IS900 positive samples had groEL PCR products. Conclusions : Our results, on the basis of the prevalence, do not support the hypothesis that M. paratuberculosis is involved in the pathogenesis of Crohn's disease.     

Difference in the Burst Patterns of Digastric and Mylohyoid Activities during Feeding in the Freely Behaving Rabbit

Burst patterns in the digastric, mylohyoid, and masseter muscles and the resultant jaw movement orbits during chewing and swallowing were investigated in the freely behaving rabbit. Activities in the posterior mylohyoid fibers consisted of two continuous bursts. Peaks in the first burst of the posterior fibers occurred in the middle part of opening and preceded the digastric burst. Peaks in the second burst occurred in the final part of opening and coincided with those in the working side of the digastric burst. After removal of the bilateral digastric muscles, the gape size during chewing was largely reduced in the final part of opening and in the early part of closing. The results suggest that (a) the digastric may have a role in opening the mandible widely beyond the rest position but may not have a major role in the control of the horizontal (mediolateral) jaw movement, (b) the posterior mylohyoid fibers may have a function as an elevator of the tongue in the early part of opening, and (c) the posterior mylohyoid fibers may have a function as a depressor of the jaw in the late part of opening. Electromyographic burst in the mylohyoid muscle began with marked activity in the mid-closing phase. The results support a role for the mylohyoid muscle as a leading muscle of swallowing. Swallowing events in the rabbit are easily distinguished from the activities of the mylohyoid muscle and the thyrohyoid muscle.     

Can t(8;21) oligoblastic leukemia be called a myelodysplastic syndrome?

The new World Health Organization (WHO) classification of hematologic malignancies has incorporated t(8;21) myelodysplastic syndromes (MDS) according to the French-American-British classification into the category of acute myeloid leukemia (AML) with t(8;21)(q22;q22), while our knowledge about clinicopathological features of t(8;21) oligoblastic leukemia is still limited. We present our experience with 12 patients meeting the FAB diagnostic criteria of MDS and having t(8;21), who were compared to 43 t(8;21) AML patients. The MDS and AML patients shared most hematomorphologic, immunophenotypic, and clinical features, whereas the differences lay along myeloid maturation. The MDS patients had higher percentages of circulating neutrophils and marrow myeloid cells beyond promyelocytes than the AML patients. The incidence of Auer rods in mature neutrophils in MDS was significantly higher than that in AML, and furthermore, the neutrophils in MDS more commonly contain t(8;21) than in AML. Our findings support the rationale for the WHO classification, and future studies on large patient populations should help clarify whether the spontaneous differentiation potential could be actively associated with a hematological manifestation of t(8;21) leukemias.     

Second allogeneic transplantation using umbilical cord blood for a patient with relapsed ALK+ anaplastic large cell lymphoma after allogeneic bone marrow transplantation in the era of ALK inhibitors: A case report

Rationale:Anaplastic lymphoma kinase (ALK) + anaplastic large cell lymphoma (ALCL) is considered as a good prognosis lymphoma. However, in an extremely rare subset of patients, ALK+ ALCL with leukemic presentations is known to be chemotherapy-resistant. Although several novel therapies have been tested, the standard therapy for relapsed/refractory ALK+ ALCL has not been established yet.Patient concerns:An 18-year-old female patient who had conventional chemotherapy- and Brentuximab Vedotin (BV)-resistant ALK+ ALCL with leukemic presentation. She was successfully treated with an ALK inhibitor, crizotinib. Crizotinib induced complete remission (CR) and bridged to allogeneic bone marrow transplantation (BMT).Diagnosis:However, her ALCL relapsed on day 60 after BMT and she developed high grade fever and lymphadenopathy.Intervention:Although crizotinib was given to the patient immediately after relapse, she developed grade 3 nausea and could not continue to take it. Then, we gave alectinib to the patient, which promptly induced sustained CR without any further chemotherapy. The patient received second stem cell transplantation using umbilical cord blood with myeloablative regimen in 2^nd CR.Outcomes:The patient has been in CR under maintenance therapy of alectinib for more than 16 months.Lessons:Both ALK inhibitors demonstrated drastic efficacy for our patient who had chemotherapy- and BV-resistant ALK+ ALCL with leukemic presentation. Alectinib showed less gastro-intestinal toxicity than crizotinib and the patient was able to take it even at the relatively early phase of stem cell transplantation.