Multidrug resistance (MDR) in cancer arises from cross-resistance to structurally- and functionally-divergent chemotherapeutic drugs. In particular, MDR is characterized by increased expression and activity of ATP-binding cassette (ABC) superfamily transporters. Sphingolipids are substrates of ABC proteins in cell signaling, membrane biosynthesis, and inflammation, for example, and their products can favor cancer progression. Glucosylceramide (GlcCer) is a ubiquitous glycosphingolipid (GSL) generated by glucosylceramide synthase, a key regulatory enzyme encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. Stressed cells increase de novo biosynthesis of ceramides, which return to sub-toxic levels after UGCG mediates incorporation into GlcCer. Given that cancer cells seem to mobilize UGCG and have increased GSL content for ceramide clearance, which ultimately contributes to chemotherapy failure, here we investigated how inhibition of GSL biosynthesis affects the MDR phenotype of chronic myeloid leukemias. We found that MDR is associated with higher UGCG expression and with a complex GSL profile. UGCG inhibition with the ceramide analog d-threo-1-(3,4,-ethylenedioxy)phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (EtDO-P4) greatly reduced GSL and monosialotetrahexosylganglioside levels, and co-treatment with standard chemotherapeutics sensitized cells to mitochondrial membrane potential loss and apoptosis. ABC subfamily B member 1 (ABCB1) expression was reduced, and ABCC-mediated efflux activity was modulated by competition with nonglycosylated ceramides. Consistently, inhibition of ABCC-mediated transport reduced the efflux of exogenous C6-ceramide. Overall, UGCG inhibition impaired the malignant glycophenotype of MDR leukemias, which typically overcomes drug resistance through distinct mechanisms. This work sheds light on the involvement of GSL in chemotherapy failure, and its findings suggest that targeted GSL modulation could help manage MDR leukemias.

Previous studies indicated that circular RNAs (circRNA) played vital roles in the development of non–small cell lung cancer (NSCLC). Although hsa_circ_0014130 might be a potential NSCLC biomarker, its function in NSCLC remains unknown. Thus, this study aimed to investigate the role of hsa_circ_0014130 in the progression of NSCLC. The levels of hsa_circ_0014130 in NSCLC tissues and adjacent normal tissues were determined by qRT-PCR. In addition, the expressions of Bcl-2 and cleaved caspase-3 in A549 cells were detected with Western blot analysis. Meanwhile, the dual luciferase reporter system assay was used to determine the interaction of hsa_circ_0014130 and miR-136-5p or Bcl-2 and miR-136-5p in NSCLC, respectively. The level of hsa_circ_0014130 was significantly upregulated in NSCLC tissues. Downregulation of hsa_circ_0014130 markedly inhibited the proliferation and invasion of A549 cells via inducing apoptosis. In addition, downregulation of hsa_circ_0014130 inhibited the tumorigenesis of subcutaneous A549 xenograft in mice in vivo. Meanwhile, mechanistic analysis indicated that downregulation of hsa_circ_0014130 decreased the expression of miR-136-5p–targeted gene Bcl-2 via acting as a competitive "sponge" of miR-136-5p. In this study, we found that hsa_circ_0014130 was upregulated in NSCLC tissues. In addition, hsa_circ_0014130 functions as a tumor promoter in NSCLC to promote tumor growth through upregulating Bcl-2 partially via "sponging" miR-136-5p.

Autophagy is a genetically regulated process of adaptation to metabolic stress and was recently shown to be involved in the treatment response of chronic myeloid leukemia (CML). However, in vivo data are limited and the molecular mechanism of autophagy regulators in the process of leukemogenesis is not completely understood. Here we show that Beclin-1 knockdown, but not Atg5 deletion in a murine CML model leads to a reduced leukemic burden and results in a significantly prolonged median survival of targeted mice. Further analyses of murine cell lines and primary patient material indicate that active BCR-ABL directly interacts with BECLIN-1 and phosphorylates its tyrosine residues 233 and 352, resulting in autophagy suppression. By using phosphorylation-deficient and phosphorylation-mimic mutants, we identify BCR-ABL induced BECLIN-1 phosphorylation as a crucial mechanism for BECLIN-1 complex formation: interaction analyses exhibit diminished binding of the positive autophagy regulators UVRAG, VPS15, ATG14 and VPS34 and enhanced binding of the negative regulator Rubicon to BCR-ABL-phosphorylated BECLIN-1. Taken together, our findings show interaction of BCR-ABL and BECLIN-1 thereby highlighting the importance of BECLIN-1-mediated autophagy in BCR-ABL⁺ cells.

Although highly effective, BCR-ABL1 tyrosine kinase inhibitors do not target chronic myeloid leukemia (CML) stem cells. Most patients relapse upon tyrosine kinase inhibitor therapy cessation. We reported previously that combined BCR-ABL1 and BCL-2 inhibition synergistically targets CML stem/progenitor cells. p53 induces apoptosis mainly by modulating BCL-2 family proteins. Although infrequently mutated in CML, p53 is antagonized by MDM2, which is regulated by BCR-ABL1 signaling. We hypothesized that MDM2 inhibition could sensitize CML cells to tyrosine kinase inhibitors. Using an inducible transgenic Scl-tTa-BCR-ABL1 murine CML model, we found, by RT-PCR and CyTOF proteomics increased p53 signaling in CML bone marrow (BM) cells compared with controls in CD45⁺ and linage-SCA-1⁺C-KIT⁺ populations. CML BM cells were more sensitive to exogenous BH3 peptides than controls. Combined inhibition of BCR-ABL1 with imatinib and MDM2 with DS-5272 increased NOXA level, markedly reduced leukemic linage-SCA-1⁺C-KIT⁺ cells and hematopoiesis, decreased leukemia burden, significantly prolonged the survival of mice engrafted with BM cells from Scl-tTa-BCR-ABL1 mice, and significantly decreased CML stem cell frequency in secondary transplantations. Our results suggest that CML stem/progenitor cells have increased p53 signaling and a propensity for apoptosis. Combined MDM2 and BCR-ABL1 inhibition targets CML stem/progenitor cells and has the potential to improve cure rates for CML.

Mutation and translocation of fibroblast growth factor receptors often lead to aberrant signaling and cancer. This work focuses on the t(8;22)(p11;q11) chromosomal translocation which creates the breakpoint cluster region (BCR) fibroblast growth factor receptor1 (FGFR1) (BCR-FGFR1) fusion protein. This fusion occurs in stem cell leukemia/lymphoma, which can progress to atypical chronic myeloid leukemia, acute myeloid leukemia, or B-cell lymphoma. This work focuses on the biochemical characterization of BCR-FGFR1 and identification of novel therapeutic targets. The tyrosine kinase activity of FGFR1 is required for biological activity as shown using transformation assays, interleukin-3 independent cell proliferation, and liquid chromatography/mass spectroscopy analyses. Furthermore, BCR contributes a coiled-coil oligomerization domain, also essential for oncogenic transformation by BCR-FGFR1. The importance of salt bridge formation within the coiled-coil domain is demonstrated, as disruption of three salt bridges abrogates cellular transforming ability. Lastly, BCR-FGFR1 acts as a client of the chaperonin heat shock protein 90 (Hsp90), suggesting that BCR-FGFR1 relies on Hsp90 complex to evade proteasomal degradation. Transformed cells expressing BCR-FGFR1 are sensitive to the Hsp90 inhibitor Ganetespib, and also respond to combined treatment with Ganetespib plus the FGFR inhibitor BGJ398. Collectively, these data suggest novel therapeutic approaches for future stem cell leukemia/lymphoma treatment: inhibition of BCR oligomerization by disruption of required salt bridges; and inhibition of the chaperonin Hsp90 complex.

Purpose:

Multiple myeloma (MM) patients with disease refractory to all available drugs have a poor outcome, indicating the need for new agents with novel mechanisms of action.

Purpose:

Preclinical data demonstrating androgen receptor (AR)–positive (AR⁺) triple-negative breast cancer (TNBC) cells are sensitive to AR antagonists, and PI3K inhibition catalyzed an investigator-initiated, multi-institutional phase Ib/II study TBCRC032. The trial investigated the safety and efficacy of the AR-antagonist enzalutamide alone or in combination with the PI3K inhibitor taselisib in patients with metastatic AR⁺ (≥10%) breast cancer.

8p11 myeloproliferative syndrome (EMS) represents a unique World Health Organization (WHO)-classified hematologic malignancy defined by translocations of the FGFR1 receptor. The syndrome is a myeloproliferative neoplasm characterized by eosinophilia and lymphadenopathy, with risk of progression to either acute myeloid leukemia (AML) or T- or B-lymphoblastic lymphoma/leukemia. Within the EMS subtype, translocations between breakpoint cluster region (BCR) and fibroblast growth factor receptor 1 (FGFR1) have been shown to produce a dominant fusion protein that is notoriously resistant to tyrosine kinase inhibitors (TKIs). Here, we report two cases of BCR–FGFR1⁺ EMS identified via RNA sequencing (RNA-seq) and confirmed by fluorescence in situ hybridization (FISH). Sanger sequencing revealed that both cases harbored the exact same breakpoint. In the first case, the patient presented with AML-like disease, and in the second, the patient progressed to B-cell acute lymphoblastic leukemia (B-ALL). Additionally, we observed that that primary leukemia cells from Case 1 demonstrated sensitivity to the tyrosine kinase inhibitors ponatinib and dovitinib that can target FGFR1 kinase activity, whereas primary cells from Case 2 were resistant to both drugs. Taken together, these results suggest that some but not all BCR–FGFR1 fusion positive leukemias may respond to TKIs that target FGFR1 kinase activity.

Don't analyse them too closely, they didn't have HD in the 1970s.

A long-standing hypothesis suggests the BCG vaccine also serves to generally enhance the immune system, meaning it could protect against covid-19, and trials are under way to find out

The BCG tuberculosis vaccine boosts the production of immune cells and this may explain how it protects newborns from dying of sepsis

BRITONS flocked outside to celebrate the 75th anniversary of VE Day yesterday, which caused major backlash online, especially against the BBC.

Siemens is preparing for a prolonged economic trough triggered by the COVID-19 pandemic, Chief Executive Joe Kaeser told CNBC on Friday after releasing fiscal second-quarter results.

WBC world heavyweight champion Vitali Klitschko will defend his title against Poland's Albert Sosnowski in Schalke's soccer stadium on May 29, the Ukrainian said on Tuesday.

Follow the latest coronavirus sports news HERE Follow our live Covid-19 updates HERE

Read our live coronavirus updates HERE Coronavirus: The symptoms

Follow our live coronavirus updates HERE Coronavirus: The symptoms

Some of Britain's most famous faces united to entertain the nation as part of BBC One's Big Night In , which raised more than £27 million to help support vulnerable people during the coronavirus pandemic.

Not for one Spanish TV anchor, whose video-chat blunder might have cost him his relationship.

Phases beginning mid-May see businesses restart, parks open, kids return to schools and childcare. 

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Some 30,000 patients added to waitlist as hospital beds held open for possible pandemic surge. 

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SXScreeners: Shorts and soundtracks rule this Amazon-hosted digital film fest

Time to catch up on some of the greatest movies ever made.

Those that leapfrogged the value of Canada's largest bank in the past have faltered — think Valeant, BlackBerry and Nortel

Follow our live coronavirus updates HERE Coronavirus: The symptoms

Actor returns with his beloved dog for kids channel's 'Tom Hardy week'

New clip gives viewers a sense of what the much-anticipated series will be like

'It's very weird without an audience,' one fan wrote

Beloved sitcom was last revived for a Comic Relief sketch in 2015

'The Real Michael Jackson' aired on BBC2 in March

Comedian is asking for nurses, retail workers and other key workers to record themselves marching to Tony Christie's cheesy hit

Former soap star was forced to defend his recent ITV programme On The NHS Frontline this month

Brooker's wry look at the world's events last aired in December 2016

At least eight different Doctors will feature in the clip

The BBC's charity event will star Lenny Henry, Catherine Tate and many more famous faces

Charity event sketch also saw Reverend Geraldine make a 'chocolate bra' and speak of her friends on the Dibley Parish Council

Comedy sketch also saw Stephen Fry reprise one of his most famous Blackadder characters

Stand-up comic and actor recreated his 2005 sketch to raise money for Comic Relief and Children in Need

Joke saw wheelchair-bound character Andy telling his carer, Lou, that he wished to have a bat for dinner

Government has pledged to match the total raised from the three-hour telethon

From Vicar of Dibley to Catherine Tate via The Trip, there was a lot packed into tonight's three-hour charity marathon, writes Alexandra Pollard

Lenny Henry, Catherine Tate and many more famous faces starred in the fundraiser