Ablation of Wnt signaling in bone marrow stromal cells overcomes microenvironment-mediated drug resistance in acute myeloid leukemia

The survival of leukemic cells is significantly influenced by the bone marrow microenvironment, where stromal cells play a crucial role. While there has been substantial progress in understanding the mechanisms and pathways involved in this crosstalk, limited data exist regarding the impact of leukemic cells on bone marrow stromal cells and their potential role in drug resistance. In this study, we identify that leukemic cells prime bone marrow stromal cells towards osteoblast lineage and promote drug resistance. This biased differentiation of stroma is accompanied by dysregulation of the canonical Wnt signaling pathway. Inhibition of Wnt signaling in stroma reversed the drug resistance in leukemic cells, which was further validated in leukemic mice models. This study evaluates the critical role of leukemic cells in establishing a drug-resistant niche by influencing the bone marrow stromal cells. Additionally, it highlights the potential of targeting Wnt signaling in the stroma by repurposing an anthelmintic drug to overcome the microenvironment-mediated drug resistance.

Haploidentical Natural Killer Cell Therapy as an Adjunct to Stem Cell Transplantation for Treatment of Refractory Acute Myeloid Leukemia

Refractory acute myeloid leukemia (AML), defined as failure of two cycles of induction therapy at diagnosis or of one cycle at relapse, represents a subgroup with poor outcomes. Haploidentical natural killer cell (NK) therapy is a strategy that is being explored in refractory malignancies. Historically, at our center, patients with refractory AML have been treated with cytoreductive therapy (fludarabine + cytosine + granulocyte colony-stimulating factor ± idarubicin or mitoxantrone + etoposide) followed by 1-week rest and then reduced-intensity transplant with fludarabine + melphalan. We used the same backbone for this trial (CTRI/2019/02/017505) with the addition of CD56-positive cells from a family donor infused 1 day after the completion of chemotherapy. CD56-positive selection was done using a CliniMACS Prodigy system (Miltenyi Biotec, Bergisch Gladbach, Germany) followed by overnight incubation in autologous plasma with 2 micromolar arsenic trioxide and 500 U/mL of interleukin-2. From February 2019, 14 patients with a median age of 29 years (interquartile range [IQR]: 16.5-38.5) were enrolled in this trial. Six were females. Six had primary refractory AML while eight had relapsed refractory AML. The median CD56-cell dose infused was 46.16 × 106/kg (IQR: 25.06-70.36). One patient withdrew consent after NK cell infusion. Of the 13 patients who proceeded to transplant, five died of immediate post-transplant complications while two did not engraft but were in morphologic leukemia-free state (both subsequently died of infective complications after the second transplant). Of the remaining six patients who engrafted and survived beyond 1 month of the transplant, two developed disease relapse and died. The remaining four patients are alive and relapse free at the last follow-up (mean follow-up duration of surviving patients is 24 months). The 2-year estimated overall survival for the cohort was 28.6% ± 12.1% while the treatment-related mortality (TRM) with this approach was 38.5% ± 13.5%. Haploidentical NK cell therapy as an adjunct to transplant is safe and needs further exploration in patients with AML. For refractory AML, post-transplant NK infusion and strategies to reduce TRM while using pre-transplant NK infusion merit exploration.

Molecular characterization of triple-negative myeloproliferative neoplasms by next-generation sequencing

The role of next-generation sequencing (NGS) in identifying mutations in the driver, epigenetic regulator, RNA splicing, and signaling pathway genes in myeloproliferative neoplasms (MPNs) has contributed substantially to our understanding of the disease pathogenesis as well as disease evolution. NGS aids in determining the clonal nature of the disease in a subset of these disorders where mutations in the driver genes are not detected. There is a paucity of real-world data on the utility of this test in the characterization of triple-negative myeloproliferative neoplasms (TN-MPN). In this study, 46 samples of TN-MPN (essential thrombocythemia (ET) = 17; primary myelofibrosis (PMF) = 23; & myeloproliferative neoplasm unclassified (MPN-u) = 6) were screened for markers of clonality using targeted NGS. Among these, 25 (54.3%) patients had mutations that would help determine the clonal nature of the disease. Eight of the 17 TN-ET (47%) and 13 of the 23 TN-PMF (56.5%) patients had noncanonical mutations in the driver genes and mutations in the genes involved in epigenetic regulation. Identification of mutations categorized as high molecular markers (HMR) in 2 patients helped classify them as PMF with high risk according to the MIPSS 70 scoring system. A novel mutation in the MPIG6B (C6orf25) gene associated with childhood myelofibrosis was detected in a 14-year-old girl. The presence of clonal hematopoiesis could be confirmed in four of the six MPN-u patients in this cohort. This study demonstrates the utility of NGS in improving the characterization of TN-MPN by establishing clonality and detecting noncanonical mutations in driver genes, thereby aiding in clinical decision-making.

3D printing of alginate dialdehyde-gelatin (ADA-GEL) hydrogels incorporating phytotherapeutic icariin loaded mesoporous SiO2-CaO nanoparticles for bone tissue engineering

3D printing enables a better control over the microstructure of bone restoring constructs, addresses the challenges seen in the preparation of patient-specific bone scaffolds, and overcomes the bottlenecks that can appear in delivering drugs/growth factors promoting bone regeneration. Here, 3D printing is employed for the fabrication of an osteogenic construct made of hydrogel nanocomposites. Alginate dialdehyde-gelatin (ADA-GEL) hydrogel is reinforced by the incorporation of bioactive glass nanoparticles, i.e. mesoporous silica-calcia nanoparticles (MSNs), in two types of drug (icariin) loading. The composites hydrogel is printed as superhydrated composite constructs in a grid structure. The MSNs not only improve the mechanical stiffness of the constructs but also induce formation of an apatite layer when the construct is immersed in simulated body fluid (SBF), thereby promoting cell adhesion and proliferation. The nanocomposite constructs can hold and deliver icariin efficiently, regardless of its incorporation mode, either as loaded into the MSNs or freely distributed within the hydrogel. Biocompatibility tests showed that the hydrogel nanocomposites assure enhanced osteoblast proliferation, adhesion, and differentiation. Such optimum biological properties stem from the superior biocompatibility of ADA-GEL, the bioactivity of the MSNs, and the supportive effect of icariin in relation to cell proliferation and differentiation. Taken together, given the achieved structural and biological properties and effective drug delivery capability, the hydrogel nanocomposites show promising potential for bone tissue engineering.

A phase II study evaluating the role of bortezomib in the management of relapsed acute promyelocytic leukemia treated upfront with arsenic trioxide

The standard‐of‐care for patients with acute promyelocytic leukemia (APL) relapsing after upfront arsenic trioxide (ATO) therapy is not defined. The present study was undertaken to evaluate the safety of addition of bortezomib to ATO in the treatment of relapsed APL based on our previously reported preclinical data demonstrating synergy between these agents. This was an open label, nonrandomized, phase II, single‐center study. We enrolled 22 consecutive patients with relapsed APL. The median age was 26.5 years (interquartile range 17.5 to 41.5). The median time from initial diagnosis to relapse was 23.1 months (interquartile range 15.6 to 43.8). All patients achieved hematological remission at a median time of 45 days (range 40‐63). Nineteen patients were in molecular remission at the end of induction. Grade 3 adverse events occurred in eight instances with one patient requiring discontinuation of therapy for grade 3 neuropathy. Twelve (54.5%) patients underwent autologous transplantation (auto‐SCT) in molecular remission while the rest opted for maintenance therapy. The median follow‐up was 48 months (range 28‐56.3). Of the patients undergoing auto‐SCT, all except one was alive and relapse free at last follow‐up. Of the patients who opted for maintenance therapy, three developed a second relapse. For treatment of APL relapsing after upfront ATO therapy, addition of bortezomib to a standard ATO‐based salvage regimen is safe and effective. This trial was registered at http://www.clinicaltrials.gov as NCT01950611.

Stromal cells downregulate miR-23a-5p to activate protective autophagy in acute myeloid leukemia

Complex molecular cross talk between stromal cells and the leukemic cells in bone marrow is known to contribute significantly towards drug-resistance. Here, we have identified the molecular events that lead to stromal cells mediated therapy-resistance in acute myeloid leukemia (AML). Our work demonstrates that stromal cells downregulate miR-23a-5p levels in leukemic cells to protect them from the chemotherapy induced apoptosis. Downregulation of miR-23a-5p in leukemic cells leads to upregulation of protective autophagy by targeting TLR2 expression. Further, autophagy inhibitors when used as adjuvants along with conventional drugs can improve drug sensitivity in vitro as well in vivo in a mouse model of leukemia. Our work also demonstrates that this mechanism of bone marrow stromal cell mediated regulation of miR-23a-5p levels and subsequent molecular events are relevant predominantly in myeloid leukemia. Our results illustrate the critical and dynamic role of the bone marrow microenvironment in modulating miRNA expression in leukemic cells which could contribute significantly to drug resistance and subsequent relapse, possibly through persistence of minimal residual disease in this environment.

Galectin-3: an emerging biomarker in stroke and cerebrovascular diseases

The carbohydrate-binding molecule galectin-3 has garnered significant attention recently as a biomarker for various conditions ranging from cardiac disease to obesity. Although there have been several recent studies investigating its role in stroke and other cerebrovascular diseases, awareness of this emerging biomarker in the wider neurology community is limited. We performed a systematic search in PubMed, Embase, Scopus, CINAHL, Clinicaltrials.gov and the Cochrane library in November and December 2016 for articles related to galectin-3 and cerebrovascular disease. We included both human and pre-clinical studies in order to provide a comprehensive view of the state of the literature on this topic. The majority of the relevant literature focuses on stroke, cerebral ischemia and atherosclerosis, but some recent attention has also been devoted to intracranial and subarachnoid hemorrhage. Higher blood levels of galectin-3 correlate with worse outcomes in atherosclerotic disease as well as in intracranial and subarachnoid hemorrhage in human studies. However, experimental evidence supporting the role of galectin-3 in these phenotypes is not as robust. It is likely that the role of galectin-3 in the inflammatory cascade within the central nervous system following injury is responsible for many of its effects, but its varied physiological functions and multiple sites of expression mean that it may have different effects depending on the nature of the disease condition and the time since injury. In summary, experimental and human research raises the possibility that galectin-3, which is closely linked to the inflammatory cascade, could be of value as a prognostic marker and therapeutic target in cerebrovascular disease.

Galectin-3 and risk of ischaemic stroke: Reasons for Geographic and Racial Differences in Stroke cohort

BACKGROUND AND PURPOSE

Galectin-3 is a biomarker of atherosclerotic and cardiovascular disease, and may be a useful marker for ischaemic stroke risk.

METHODS

The Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort enrolled and examined 30 239 US participants between 2003 and 2007 (41% black, 59% white and 55% in the southeastern stroke belt). Baseline galectin-3 was measured in 526 subjects with incident ischaemic stroke over 5.4 years and in a cohort random sample (CRS) of 947 participants. Cox proportional hazards models were used to calculate hazard ratios (HRs) of ischaemic stroke by quartiles of galectin-3.

RESULTS

In the CRS, galectin-3 was significantly higher with older age, black race, female sex, body mass index, hypertension, diabetes mellitus and kidney disease, and also in those who developed incident stroke. Participants with galectin-3 levels in the fourth versus first quartile had a 2.3-fold increased stroke risk [95% confidence interval (CI) 1.6, 3.4] in an unadjusted model. An interaction with age was found (P = 0.06), and therefore age-stratified analyses were performed. Amongst those younger than age 64, baseline galectin-3 in the second-fourth quartiles was associated with increased stroke risk (HR 3.0, 95% CI 1.6, 5.5) compared to the first quartile in an age-, race- and sex-adjusted model. The HR was 2.0 (95% CI 1.0, 4.0) with multivariable adjustment. There was no association amongst older participants.

CONCLUSIONS

Galectin-3 was associated with incident ischaemic stroke in younger but not older individuals. Confirmation of this finding, and elucidation of its implications for stroke pathophysiology and prevention, is needed.

“The great divide”: skill gap between the employer’s expectations and skills possessed by employees

Purpose

The purpose of this paper is to emphasise on demand supply skill gap of human resources in India which would help generate reasons for the same and the necessary steps to be taken to improve the situation and bridge the skill gap helping maximum number of the students becoming employable. It will put an impact on various stakeholders about the steps to be taken in bridging the gap in India.

Design/methodology/approach

A review of available literature was done in order to understand the reasons behind the increasing skill gap despite a vibrant and abundance of young population.

Findings

The findings of the paper implicitly point out that a vast skill gap is prevailing in the Indian labour market and there is a dearth of human intellectual capital in India. Also it emphasises on the role of various stakeholders in bridging the skill gap by investing in workforce of today for a better tomorrow.

Originality/value

Based on literature review, the paper makes specific recommendations to various stakeholders (industry, academia, and government) in bridging the skill gap and would serve as a roadmap for companies guiding them to follow certain strategies to improve skills of future workers by investing in them and growing their own talent pool; and is an attempt to highlight the fact that India’s jobless growth is not going to reap the demographic dividend and certainly the increasing skill gap needs to be bridged ASAP.

Spontaneous resolution of double anterior chamber with perforation of Descemet's membrane in deep anterior lamellar keratoplasty

Deep anterior lamellar keratoplasty (DALK) using Dr. Anwar's big bubble technique was performed for a patient with granular dystrophy. Intraoperatively, a perforation of the Descemet's membrane (DM) was noted inferonasally. Though the surgery was completed, the donor graft appeared to have an intact endothelium, which was inadvertently left behind by the surgeon. Intraoperatively, there was a perforation of inferonasal DM and surgery was completed by inadvertently placing a donor with an intact endothelium. Postoperatively the patient presented with a complete DM detachment and a resultant double anterior chamber (DAC). In spite of two attempts at an air tamponade on the first and fifth post operative days, the DAC still persisted. Surprisingly, during the 6^th week follow up visit, there was a complete resolution of the DAC as well as total recovery of vision. This interesting case clearly exemplifies that, in spite of failed attempts at air tamponade, a DM detachment and a DAC due to DM perforation following a DALK procedure can resolve spontaneously with good visual outcome.

Neoadjuvant platinum-based chemotherapy (CT) for triple-negative locally advanced breast cancer (LABC): Retrospective analysis of 125 patients

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Background: Triple-negative breast cancer (TNBC), defined by lack of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, accounts for 15–20% of all breast cancers and is associated with poor prognosis. There is no consensus regarding optimal CT for treatment of such patients. Preclinical data suggests TNBC may be sensitive to platinums because of deficiencies in BRCA-associated DNA repair. The aim of this study was to evaluate pathologic complete response (pCR) and overall survival (OS) in patients with TNBC treated with neoadjuvant platinum-based CT. Methods: We identified 674 patients with LABC who received neoadjuvant CT between January 1999 and June 2008 at University of Miami. Of these, 125 (18.5%) had histopathologic confirmation of TNBC. All patients received neoadjuvant platinum salts + docetaxel. 76 (61%) also received neoadjuvant AC, while 42 (34%) received adjuvant AC. pCR was defined as no residual invasive disease in breast and axilla. OS was calculated according to Kaplan-Meier. Results: Demographics: median age 50 (28–86 years). 60% premenopausal. TNM stage distribution: T1 0.9%, T2 5.2%, T3 53.4%, T4 40.5%, N0 25.0%, N1 36.2%, N2 35.4%, N3 3.4%, M0 100%, inflammatory 11%, median tumor size = 9.5 cm. Follow up duration ranged from 0.3 to 8.9 years. pCR was observed in 42 of 125 patients (34%; 95% CI 26–43%). Among patients receiving neoadjuvant AC, 30 of 76 (40%; 95% CI 28–51%) had pCR, while amongst those receiving adjuvant AC, 12 of 42 (29%, 95% CI 16–45%) had pCR at the time of definitive surgery. Patients achieving pCR had significantly higher OS (5-yr rate = 73% in pCR, vs. 49% in non-pCR; p < 0.001). OS in TNBC patients receiving cisplatin/docetaxel was significantly superior to those receiving carboplatin/docetaxel (11 mortality events out of 78 patients receiving cisplatin based CT vs 24 out of 47 receiving carboplatin based CT logrank p = 0.001). Conclusions: To date, this is the largest single institution cohort of locally advanced TNBC uniformly treated with platinum+docetaxel-based CT regimens. Platinum/docetaxel-based neoadjuvant CT provided high rates of pCR and excellent OS for women with locally advanced TNBC.

No significant financial relationships to disclose.

Surgical management and genetic analysis of a Chinese family with the S171P mutation in the UBIAD1 gene, the gene for Schnyder corneal dystrophy

BACKGROUND

To describe the underlying molecular genetic basis, surgical management and phenotypic variation of Schnyder corneal dystrophy (SCD) identified in a four-generation Chinese family.

METHODS

This is an interventional case series of 13 members from a non-consanguineous Chinese family. All patients underwent complete ophthalmological examination and slit-lamp photography. Subsequent corneal transplantations were performed (n = 3). Blood samples were taken for DNA extraction and subsequent genetic analysis.

RESULTS

Genotyping indicated linkage to the locus at chromosome 1p36. Screening of the UBIAD1 gene identified a highly conserved mutation, Ser171Pro. Phenotypic variation in this large pedigree is similar to that seen in Caucasian patients. Surgical management of patients with anterior lamellar keratoplasty and deep anterior lamellar keratoplasty showed good visual outcomes.

CONCLUSIONS

The S171P mutation is described for the first time in a Chinese family. This is the largest non-Caucasian pedigree described with SCD. Visual rehabilitation may be performed successfully with lamellar surgical procedures as opposed to full-thickness corneal grafts.

Increased permeability in dextran sulphate colitis in rats: time course of development and effect of butyrate

BACKGROUND

Increased mucosal permeability is an important factor in the genesis of mucosal inflammation in inflammatory bowel disease. This study examined the time course of increased permeability and the effect of butyrate on permeability in experimental colitis in rats.

METHODS

Colitis was induced in albino rats by administration of 4% dextran sulphate sodium (DSS) orally for up to 7 days. Rats were killed sequentially after 1-7 days of DSS feeding and compared with control animals. Distal colon sheets, from normal and DSS rats, were mounted in Ussing chambers. Electric resistance and passive permeation of 14C-mannitol were measured over 90 min. In control and 5-day DSS rats additional permeability measurements were made in the presence of butyrate (25 mmol/l) in the bathing solutions. The permeability of the normal distal colon was measured after addition of DSS in vitro. Sections of colon were examined by light microscopy. The viability of colonocytes, from normal and DSS rat colon, was measured by release of lactate dehydrogenase immediately and during a 60-min incubation after isolation.

RESULTS

Focal mild inflammation and shedding of epithelium were noted after 2 days of DSS administration; crypt loss with flattened epithelium in adjacent areas after 5 days; and fibrosis after 7 days. Decreased epithelial cell survival after 60 min of incubation was noted after 1 day of DSS administration, whereas decreased viability at the time of isolation was noted after 2 days of DSS administration (viability, 72.7% +/- 1.4%; mean +/- standard error) compared with control (89.3% +/- 0.8%) (P < 0.01). Increased permeability was noted after 1 day of DSS administration. Electric resistance (mu omega/cm2/h) was significantly reduced after 1 day of DSS administration to 85.9 +/- 4.6 (mean +/- standard error) compared with control animals (117.2 +/- 2.2; P < 0.001). Serosa-mucosa flux of mannitol (micromol/cm2/h) was also significantly increased after 1 day of DSS feeding (0.169 +/- 0.01) compared with control (0.061 +/- 0.08) (P < 0.01). Electric resistance and mannitol permeability were significantly returned towards normal by the presence of butyrate. DSS added directly to the bathing solution did not significantly alter the colon permeability in vitro.

CONCLUSIONS

Increased mucosal permeability is a very early change in colitis induced by DSS, is accompanied by decreased cell survival, and precedes detectable changes in histology. Reversal of increased mucosal permeability by butyrate may explain its utility in the therapy of inflammatory disease of the colon.

Butyrate hastens restoration of barrier function after thermal and detergent injury to rat distal colon in vitro

BACKGROUND

Epithelial migration restores barrier function after superficial injury to any mucosa. The present study aimed to determine whether butyrate, important to colonic epithelial physiology in diverse ways, influences restoration of barrier function in the injured rat colon.

METHODS

Rat distal colon was transiently exposed in vitro to heat (55 degrees C for 10 sec) or to detergent (deoxycholic acid, 7.5 mM, for 15 min), and tissue damage was verified histologically. Epithelial barrier function was assessed, in colon tissue mounted in Ussing chambers, by measuring electric resistance and passive serosa-to-mucosa fluxes of 22Na and of 14C PEG 4000 under voltage clamp conditions. Studies were done in the absence and presence of 25 mM butyrate in the bathing solutions.

RESULTS

Heat exposure induced superficial epithelial damage, and the electric resistance decreased significantly. This was accompanied by increase in flux of 14C PEG and increased passive flux of 22Na. Electric resistance was significantly higher, and PEG flux significantly lower, in tissues bathed with butyrate. Exposure to deoxycholic acid also induced superficial epithelial damage, reduced tissue electric resistance, and increased passive flux of Na and PEG. Electric resistance was significantly higher, and PEG flux significantly lower, in injured tissues bathed in butyrate, than in injured tissues bathed in butyrate-free solution. The effect of butyrate on restoration of electric resistance towards normal was seen in colon both from adult rats and from younger rats that were 2 or 6 weeks old.

CONCLUSIONS

Butyrate enhanced restoration of mucosal barrier function in rat distal colon in response to heat and detergent injury.