Leukaemia exposure alters the transcriptional profile and function of BCR::ABL1 negative macrophages in the bone marrow niche

Macrophages are fundamental cells of the innate immune system that support normal haematopoiesis and play roles in both anti-cancer immunity and tumour progression. Here we use a chimeric mouse model of chronic myeloid leukaemia (CML) and human bone marrow (BM) derived macrophages to study the impact of the dysregulated BM microenvironment on bystander macrophages. Utilising single-cell RNA sequencing (scRNA-seq) of Philadelphia chromosome (Ph) negative macrophages we reveal unique subpopulations of immature macrophages residing in the CML BM microenvironment. CML exposed macrophages separate from their normal counterparts by reduced expression of the surface marker CD36, which significantly reduces clearance of apoptotic cells. We uncover aberrant production of CML-secreted factors, including the immune modulatory protein lactotransferrin (LTF), that suppresses efferocytosis, phagocytosis, and CD36 surface expression in BM macrophages, indicating that the elevated secretion of LTF is, at least partially responsible for the supressed clearance function of Ph- macrophages.

A single-cell atlas identifies pretreatment features of primary imatinib resistance in chronic myeloid leukemia

Primary resistance to tyrosine kinase inhibitors (TKIs) is a significant barrier to optimal outcomes in chronic myeloid leukemia (CML), but factors contributing to response heterogeneity remain unclear. Using single-cell RNA (scRNA) sequencing, we identified 8 statistically significant features in pretreatment bone marrow, which correlated with either sensitivity (major molecular response or MMR) or extreme resistance to imatinib (eventual blast crisis [BC] transformation). Employing machine-learning, we identified leukemic stem cell (LSC) and natural killer (NK) cell gene expression profiles predicting imatinib response with >80% accuracy, including no false positives for predicting BC. A canonical erythroid-specifying (TAL1/KLF1/GATA1) regulon was a hallmark of LSCs from patients with MMR and was associated with erythroid progenitor [ERP] expansion in vivo (P < .05), and a 2- to 10-fold (6.3-fold in group A vs 1.09-fold in group C) erythroid over myeloid bias in vitro. Notably, ERPs demonstrated exquisite TKI sensitivity compared with myeloid progenitors (P < .001). These LSC features were lost with progressive resistance, and MYC- and IRF1-driven inflammatory regulons were evident in patients who progressed to transformation. Patients with MMR also exhibited a 56-fold expansion (P < .01) of a normally rare subset of hyperfunctional adaptive-like NK cells, which diminished with progressive resistance, whereas patients destined for BC accumulated inhibitory NKG2A+ NK cells favoring NK cell tolerance. Finally, we developed antibody panels to validate our scRNA-seq findings. These panels may be useful for prospective studies of primary resistance, and in assessing the contribution of predetermined vs acquired factors in TKI response heterogeneity.

The RUNX Family of Proteins, DNA Repair, and Cancer

The RUNX family of transcription factors, including RUNX1, RUNX2, and RUNX3, are key regulators of development and can function as either tumor suppressors or oncogenes in cancer. Emerging evidence suggests that the dysregulation of RUNX genes can promote genomic instability in both leukemia and solid cancers by impairing DNA repair mechanisms. RUNX proteins control the cellular response to DNA damage by regulating the p53, Fanconi anemia, and oxidative stress repair pathways through transcriptional or non-transcriptional mechanisms. This review highlights the importance of RUNX-dependent DNA repair regulation in human cancers.

Transesophageal Echocardiography in Bentall Surgery: Hope or Hype?

A 57-year-old male patient who is a known case of hypertension well controlled on ramipril presented with a history of shortness of breath and palpitation of 3 months duration. The symptoms were insidious in onset; however, it progressed rapidly over the period of 3 months, wherein at present the patient feels breathless in performing normal daily activities of living making him New York Heart Association class III patient. Palpitations are regular in nature and present throughout the time and are exacerbated on performing even light activities within his house. There was associated swelling of bilateral lower limbs that usually improved after a night's rest; however, it was not completely resolved. The individual did not give any history of chest pain, presyncope, syncope, or any other symptoms that pointed toward a cardiac condition.

Integrating genetic and epigenetic factors in chronic myeloid leukemia risk assessment: toward gene expression-based biomarkers

Cancer treatment is constantly evolving from a one-size-fits-all towards bespoke approaches for each patient. In certain solid cancers, including breast and lung, tumor genome profiling has been incorporated into therapeutic decision-making. For chronic phase chronic myeloid leukemia (CML), while tyrosine kinase inhibitor therapy is the standard treatment, current clinical scoring systems cannot accurately predict the heterogeneous treatment outcomes observed in patients. Biomarkers capable of segregating patients according to outcome at diagnosis are needed to improve management, and facilitate enrollment in clinical trials seeking to prevent blast crisis transformation and improve the depth of molecular responses. To this end, gene expression (GE) profiling studies have evaluated whether GE signatures at diagnosis are clinically informative. Patient material from a variety of sources has been profiled using microarrays, RNA sequencing and, more recently, single-cell RNA sequencing. However, differences in the cell types profiled, the technologies used, and the inherent complexities associated with the interpretation of genomic data pose challenges in distilling GE datasets into biomarkers with clinical utility. The goal of this paper is to review previous studies evaluating GE profiling in CML, and explore their potential as risk assessment tools for individualized CML treatment. We also review the contribution that acquired mutations, including those seen in clonal hematopoiesis, make to GE profiles, and how a model integrating contributions of genetic and epigenetic factors in resistance to tyrosine kinase inhibitors and blast crisis transformation can define a route to GE-based biomarkers. Finally, we outline a four-stage approach for the development of GE-based biomarkers in CML.

RCA2: a scalable supervised clustering algorithm that reduces batch effects in scRNA-seq data

The transcriptomic diversity of cell types in the human body can be analysed in unprecedented detail using single cell (SC) technologies. Unsupervised clustering of SC transcriptomes, which is the default technique for defining cell types, is prone to group cells by technical, rather than biological, variation. Compared to de-novo (unsupervised) clustering, we demonstrate using multiple benchmarks that supervised clustering, which uses reference transcriptomes as a guide, is robust to batch effects and data quality artifacts. Here, we present RCA2, the first algorithm to combine reference projection (batch effect robustness) with graph-based clustering (scalability). In addition, RCA2 provides a user-friendly framework incorporating multiple commonly used downstream analysis modules. RCA2 also provides new reference panels for human and mouse and supports generation of custom panels. Furthermore, RCA2 facilitates cell type-specific QC, which is essential for accurate clustering of data from heterogeneous tissues. We demonstrate the advantages of RCA2 on SC data from human bone marrow, healthy PBMCs and PBMCs from COVID-19 patients. Scalable supervised clustering methods such as RCA2 will facilitate unified analysis of cohort-scale SC datasets.

POS0901 IXEKIZUMAB SHOWS A DISTINCT PATTERN OF PAIN IMPROVEMENT BEYOND INFLAMMATION IN RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS

Background:

The efficacy of ixekizumab (IXE) in biologic-naïve patients with radiographic axial spondyloarthritis (r-axSpA) has been previously presented using traditional axSpA outcome measures, such as BASDAI and ASAS.

Objectives:

In patients with active r-axSpA, to assess the analgesic efficacy of IXE as it relates to patient-reported and objective measures of inflammation.

Methods:

The Phase III COAST-V (NCT02696785) multi-center, randomized, double-blind, placebo (PBO)-controlled and active reference arm with adalimumab (ADA) trial investigated the efficacy of IXE in 341 patients (pts) with active r-axSpA for 52 weeks (W). Pts were initially randomized to IXEQ4W, IXEQ2W, PBO, and ADAQ2W. At W16, pts assigned to PBO and ADA were re-randomized to IXEQ2W or Q4W. Changes in spinal pain at night (SP-N) and spinal pain were measured at each study visit and analysed while controlling for CRP levels or mean of BASDAI questions 5 & 6 (Q5: Duration and Q6: Intensity of morning stiffness). Observed data analyses are presented for each group stratified by treatment arm and compared to PBO. In the initial analysis, pts were categorized into 2 sub-groups defined as “Sustained” and “Fluctuating” depending on: CRP <5 mg/L W4-16 vs. CRP ≥5 mg/L at any point beyond W4 between weeks 4-16 respectively. In a second analysis, pts were categorized based on BASDAI Q5/6 improvement: “Sustained” if ≥2-pt improvement W12-16 vs. “Fluctuating” if <2-pt improvement at any point beyond W12 between W12-16.

Results:

Between W0 and W16, pts treated (tx) with IXEQ4W experienced greater reduction in SP-N than pts tx with ADA, in both CRP sustained and fluctuating groups (Fig 1a). Pts in the IXEQ4W and ADA arms showed different trajectories of pain improvement in the CRP fluctuating groups. For the pts with a fluctuating CRP ≥5 mg/L, pts in IXEQ4W arm demonstrated a greater reduction in SP-N compared to pts in PBO arm (p < .001) at W16, whereas pts in ADA arm did not experience a reduction in SP-N compared to PBO (p = .416). For the pts with a sustained CRP <5mg/L, IXEQ4W and ADA treatments both significantly demonstrated reduction in SP-N compared to PBO at W16 (IXEQ4W: p = .002; ADA: p = .02), with IXEQ4W treatment showing a greater level of reduction (Fig 1a). The pts randomized to ADA and re-randomized to IXEQ2W or Q4W (ADA/IXE) experienced further improvement in SP-N. This effect was sustained over the 52-wk period (Fig 1b). The same pattern of improvement in SP-N was observed when controlling for the BASDAI Q5/6; the SP-N improvement was greater in pts with a sustained BASDAI Q5/6 compared to pts with a fluctuating BASDAI Q5/6, regardless of treatment (Table 1). In the fluctuating BASDAI Q5/6, for pts in ADA/IXE arm, further reduction of both spinal pain and SP-N were observed (Table 1).

Table 1.

Change in Pain Outcome at baseline, week 16 and week 52 by Inflammation Status as assessed by BASDAI or CRP levels for patients receiving placebo (PBO), adalimumab (ADA), and ixekizumab every 4 weeks (IXE Q4W)

Change from baselinePBOADAIXEQ4WbaselineWeek 16(as observed)Week 52PBO/IXE(as observed)baselineWeek 16(as observed)Week 52ADA/IXE(as observed)baselineWeek 16(as observed)Week 52(as observed)Spinal painBASDAI Q5/6 sustained7.54-3.33-4.657.21-4.07-4.57.4-4.52-4.94BASDAI Q5/6 fluctuating7.37-1.32-2.826.76-1.2-2.246.97-1.3-2.52CRP sustained7-1.53-1.936.83-2.9-3.67.23-3.57-4.21CRP fluctuating7.51-1.96-3.637.28-2-2.897.24-2.91-3.93Spinal pain at nightBASDAI Q5/6 sustained7.12-3.21-4.617.26-4.63-4.927.12-4.73-4.91BASDAI Q5/6 fluctuating7.05-1.15-2.886.6-1.2-2.497.03-2.17-2.92CRP sustained7.2-1.87-2.276.76-3.2-3.856.89-3.8-4.12CRP fluctuating7.04-1.69-3.67.24-2.21-3.397.35-3.68-4.38

Conclusion:

IXE reduced SP-N and spinal pain irrespective of CRP or morning stiffness. Additionally, pts treated with ADA re-randomized to IXE experienced a further reduction in SP-N and spinal pain. Collectively, these results support the additive benefits of IXE in reducing pain above measurable effects on inflammation.

Acknowledgements:

The authors would like to thank Eglantine Julle-Daniere for writing and editorial contributions

Disclosure of Interests:

Kurt de Vlam Speakers bureau: Eli Lilly, Novartis, Pfizer, Paid instructor for: Celgene, Amgen, Consultant of: Elil Lillyn Novartis, UCB, Galapagos, Sandoz, Pfizer, Grant/research support from: Celgene, Gaia Gallo Shareholder of: Eli Lilly, Employee of: Eli Lilly, Philip J Mease Speakers bureau: AbbVie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer, UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, GlaxoSmithKline, Janssen, Novartis, Pfizer, Sun, UCB, Grant/research support from: AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer, Sun, UCB, Proton Rahman Speakers bureau: AbbVie, Amgen, BMS, Celgene, Eli Lilly, Janssen, Merck, Novartis, Pfizer, UCB, Consultant of: AbbVie, Amgen, BMS, Celgene, Eli Lilly, Janssen, Merck, Novartis, Pfizer, UCB, Grant/research support from: Janssen, Novartis, Venkatesh Krishnan Shareholder of: Eli Lilly, Employee of: Eli Lilly, David Sandoval Shareholder of: Eli Lilly, Employee of: Eli Lilly, Chen-Yen Lin Shareholder of: Eli Lilly, Employee of: Eli Lilly, Rebecca Bolce Shareholder of: Eli Lilly, Employee of: Eli Lilly, Philip G Conaghan Consultant of: personal fees from: AbbVie, AstraZeneca, BMS, Eli Lilly, EMD Serono, Flexion Therapeutics, Galapagos, Gilead, Novartis, Pfizer

Evaluation of anti-histidine-rich protein 2 monoclonal antibodies, developed by using poly (N-isopropylacrylamide) as an adjuvant for malarial diagnostic application

OBJECTIVE

To evaluate the sensitivity and the stability of the monoclonal antibodies (Aa3c10, b10c1), against truncated Histidine-rich protein 2 (PfHRP2), developed using smart polymer, poly N-isopropylacrylamide, as adjuvant for malarial diagnostic applications in comparison with the available commercial antibodies.

METHODS

Two hybridoma clones (Aa3c10, b10c1) were used for the production of ascites in BALB/c mice. Purification of monoclonal antibodies from the ascites was carried out using affinity columns. The thermal stability study of monoclonal antibodies was done by storing it at 37°C and 45°C for thirty days. The stored antibodies were analyzed using SDS-PAGE and flow-through device where the antigenantibody interaction was visualized by Protein A colloidal gold solution. Sensitivity was determined by endpoint dilution ELISA and the dissociation constant by competitive ELISA. Sensitive pair optimization was done by sandwich ELISA using biotinylated antibodies. Prototype preparation for lateral flow assay had a colloidal gold-based detection system.

RESULTS

Thermal stability experiments showed that both mAbs (Aa3c10; b10c1) are stable up to thirty days at 45°C while the commercially available mAbs were stable up to fifteen days only. Compared to commercial antibodies, the mAb Aa3c10, showed the highest sensitivity in end-point titre. In sensitive pair optimization, it was observed that the mAb, b10c1, as a detector and the mAb, Aa3c10, as a capture antibody showed the highest absorbance to detect 50pg/ml PfHRP2 antigen. The prototype formulation of lateral flow assay using the mAbs (Aa3c10; b10c1) showed good reactivity with WHO panel and no false-positive results were observed with twenty clinically negative samples and five P. vivax positive samples.

CONCLUSIONS

The novel monoclonal antibodies (Aa3c10, b10c1) against truncated PfHRP2, could be a strong potential candidates that can be included in making RDTs with better sensitivity and stability.

Lysine acetyltransferase Tip60 is required for hematopoietic stem cell maintenance

Hematopoietic stem cells (HSCs) have the potential to replenish the blood system for the lifetime of the organism. Their 2 defining properties, self-renewal and differentiation, are tightly regulated by the epigenetic machineries. Using conditional gene-knockout models, we demonstrated a critical requirement of lysine acetyltransferase 5 (Kat5, also known as Tip60) for murine HSC maintenance in both the embryonic and adult stages, which depends on its acetyltransferase activity. Genome-wide chromatin and transcriptome profiling in murine hematopoietic stem and progenitor cells revealed that Tip60 colocalizes with c-Myc and that Tip60 deletion suppress the expression of Myc target genes, which are associated with critical biological processes for HSC maintenance, cell cycling, and DNA repair. Notably, acetylated H2A.Z (acH2A.Z) was enriched at the Tip60-bound active chromatin, and Tip60 deletion induced a robust reduction in the acH2A.Z/H2A.Z ratio. These results uncover a critical epigenetic regulatory layer for HSC maintenance, at least in part through Tip60-dependent H2A.Z acetylation to activate Myc target genes.

DNA damage signalling as an anti-cancer barrier in gastric intestinal metaplasia

OBJECTIVE

Intestinal metaplasia (IM) is a premalignant stage that poses a greater risk for subsequent gastric cancer (GC). However, factors regulating IM to GC progression remain unclear. Previously, activated DNA damage response (DDR) signalling factors were shown to engage tumour-suppressive networks in premalignant lesions. Here, we interrogate the relationship of DDR signalling to mutational accumulation in IM lesions.

DESIGN

IM biopsies were procured from the gastric cancer epidemiology programme, an endoscopic surveillance programme where biopsies have been subjected to (epi)genomic characterisation. IM samples were classified as genome-stable or genome-unstable based on their mutational burden/somatic copy-number alteration (CNA) profiles. Samples were probed for DDR signalling and cell proliferation, using the markers γH2AX and MCM2, respectively. The expression of the gastric stem cell marker, CD44v9, was also assessed. Tissue microarrays representing the GC progression spectrum were included.

RESULTS

MCM2-positivity increased during GC progression, while γH2AX-positivity showed modest increase from normal to gastritis and IM stages, with further increase in GC. γH2AX levels correlated with the extent of chronic inflammation. Interestingly, genome-stable IM lesions had higher γH2AX levels underscoring a protective anti-cancer role for DDR signalling. In contrast, genome-unstable IM lesions with higher mutational burden/CNAs had lower γH2AX levels, elevated CD44v9 expression and modest promoter hypermethylation of DNA repair genes WRN, MLH1 and RAD52.

CONCLUSIONS

Our data suggest that IM lesions with active DDR will likely experience a longer latency at the premalignant state until additional hits that override DDR signalling clonally expand and promote progression. These observations provide insights on the factors governing IM progression.

Abstract 1570: Loss of mismatch repair protein MSH6 sensitizes diffuse-type gastric cancer cells to DNA-PKcs inhibitor KU60648

Diffuse-type gastric cancer (DGC) is a histologic subtype characterized by poor cellular cohesiveness, increased metastasis and poor prognosis. As preclinical models of DGC that reliably predict clinical activity of novel compounds are lacking, we generated patient-derived xenograft (PDX) models using malignant ascites from DGC patients that closely recapitulated the primary cancer. To uncover novel therapeutic targets, we applied the concept of synthetic lethality and asked if DGCs require DNA repair proteins for survival. Major DNA repair kinases ATM, ATR and DNA-PKcs in established DGC cell lines and ex vivo cell lines from PDXs (GAGA3, GAGA6 and GAS24) were inhibited using small-molecule inhibitors KU55933, VE-821 and KU60648, respectively. Interestingly, most diffuse-type gastric cells exhibited elevated lethality when DNA-PKcs, a central kinase that regulates the non-homologous end joining pathway (NHEJ), was inhibited by KU60648 as compared to the nontransformed gastric epithelial line, HFE-145. We confirmed that genetic depletion of DNA-PKcs by siRNA resulted in cell death in two PDX lines GAS24 and GAGA6 cells but not in HFE-145 cells, suggesting the dependence of these cells on DNA-PKcs for survival. Two mechanisms appear to sensitize DGC cells to DNA-PKcs inhibition; firstly, impaired homologous recombination repair in GAS24 and GAGA6 as shown by compromised ability to resolve radiation-induced γH2AX foci, and secondly, transcriptional downregulation of the mismatch repair protein, MSH6, in GAGA3 and GAGA6. Knockdown of MSH6 in GAS24 cells enhanced their sensitivity to KU60648, suggesting a functional link between MSH6 and DNA-PK function. Lastly, to develop MSH6 as a biomarker for predicting DNA-PKcs sensitivity, we analyzed MSH6 levels by immunohistochemical staining in formalin-fixed, paraffin-embedded (FFPE) tissue sample sections derived from PDXs. In these preliminary studies, MSH6 expression was lower with high heterogeneity in GAGA3 and GAGA6 compared to GAS24. In this study, we show for the first time the downregulation of DNA mismatch protein MSH6 in sporadic diffuse gastric cancer, and its potential as a therapeutic predictor for DNA-PKcs inhibition treatment.

Citation Format: Vaidehi Krishnan, Wen Min Lau, Eileen Teng, Jin Wei Tan, Haresh Sankar, Debbie Xiu En Lim, Crystal Kok Yan Pang, Ming Teh, Jimmy Bok Yan So, Patrick Tan, Yoshiaki Ito, Shing Leng Chan. Loss of mismatch repair protein MSH6 sensitizes diffuse-type gastric cancer cells to DNA-PKcs inhibitor KU60648 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1570.

Design and development of a smart knee pain relief pad based on vibration and alternate heating and cooling treatments

Knee pain is one of the main health issues faced by different people in different parts of the world. Over one fourth of the people above the age of fifty suffer from knee pain. Though there are several physiotherapy treatments for treating knee pain they are not self-applicable and those which are self-applicable by the patient are not highly efficient. This paper deals with an approach towards the use of combining two effective physiotherapy treatments which include vibrations at acupressure points on knee and alternate heating and cooling treatments. These treatments are controlled by a smart phone in which the user can choose their setting depending on intensity and places of pain. The knee pad controlled using the smart phone serves as a self-applicable and effective knee pain treatment especially for the elderly. Heating and cooling combination therapy will be a suitable alternative for treatment of musculoskeletal diseases, decreases muscle spasms, muscular pain/tension and also increases the speed of nerve conduction, thus improving range of motion. This methodology also helps to relieve the sinusitis pain, chronic low back pain and muscular sprain in athletes.

Development of a selective androgen receptor modulator for transdermal use in hypogonadal patients

We have identified a non-steroidal selective androgen receptor modulator (SARM), termed LY305, that is bioavailable through a transdermal route of administration while highly cleared via hepatic metabolism to limit parent compound exposure in the liver. Selection of this compound and its transdermal formulation was based on the optimization of skin absorption properties using both in vitro and in vivo skin models that supported PBPK modeling for human PK predictions. This molecule is an agonist in perineal muscle while being a weak partial agonist in the androgenic tissues such as prostate. When LY305 was tested in animal models of skeletal atrophy it restored the skeletal muscle mass through accelerated repair. In a bone fracture model, LY305 remained osteoprotective in the regenerating tissue and void of deleterious effects. Finally, in a small cohort of healthy volunteers, we assessed the safety and tolerability of LY305 when administered transdermally. LY305 showed a dose-dependent increase in serum exposure and was well tolerated with minimal adverse effects. Notably, there were no statistically significant changes to hematocrit or HDL after 4-week treatment period. Collectively, LY305 represents a first of its kind de novo development of a non-steroidal transdermal SARM with unique properties which could find clinical utility in hypogonadal men.

Safety and efficacy of self-expandable metal stents for obstructive proximal and distal large bowel cancer

Self-expandable metal stents are often used to treat obstructive large bowel cancers. This study assessed the safety and efficacy of colonic stent insertion carried out in a district general hospital. Methods A retrospective review was carried out between 1 January 2007 and 28 February 2014 to identify patients who underwent stent insertion for malignant colorectal obstruction. Results Seventy-five patients (median age 75.2 years, 70.6% male) with primary colorectal cancer underwent stent insertion - 53 underwent semi-elective self-expanded metal stent insertion (for subacute bowel obstruction) and 22 had emergency stent inserted (for acute bowel obstruction). The majority (88%) had self-expanded metal stents inserted for palliation. Technical and clinical success rates were 98.7% and 91.2%, respectively. One patient had stent-related perforation; there was no procedure-related mortality. Conclusion This study shows that self-expanded metal stent insertion in malignant colorectal obstruction is safe and effective and can be successfully delivered in a district general hospital with high technical and clinical success rates.

Sustained p16INK4a expression is required to prevent IR-induced tumorigenesis in mice

Exposure of murine and human tissues to ionizing radiation (IR) induces the expression of p16^INK4a, a tumor suppressor gene and senescence/aging biomarker. Increased p16^INK4a expression is often delayed several weeks post exposure to IR. In this context, it remains unclear if it occurs to suppress aberrant cellular growth of potentially transformed cells or is simply a result of IR-induced loss of tissue homeostasis. To address this question, we used a conditional p16^INK4a null mouse model and determined the impact of p16^INK4a inactivation long-term post exposure to IR. We found that, in vitro, bone marrow stromal cells exposed to IR enter DNA replication following p16^INK4a inactivation. However, these cells did not resume growth; instead, they mostly underwent cell cycle arrest in G2. Similarly, delayed inactivation of p16^INK4a in mice several weeks post exposure to IR resulted in increased BrdU incorporation and cancer incidence. In fact, we found that the onset of tumorigenesis was similar whether p16^INK4a was inactivated before or after exposure to IR. Overall, our results suggest that IR-induced p16^INK4a dependent growth arrest is reversible in mice and that sustained p16^INK4a expression is necessary to protect against tumorigenesis.

Assessment of Knowledge of Self Blood Glucose Monitoring and Extent of Self Titration of Anti-Diabetic Drugs among Diabetes Mellitus Patients - A Cross Sectional, Community Based Study

INTRODUCTION

Self blood glucose monitoring is an important context of self care in the management of diabetes mellitus. All the guidelines must be followed while performing self blood glucose monitoring and tracking of values is essential to facilitate the physician while titrating the drugs and /or doses of anti diabetes medication. Self titration by patients following self monitoring must be discouraged.

AIM

To assess the knowledge and practice of self blood glucose monitoring among diabetes patients and extent of self titration of anti diabetes medicines among diabetes patients based on self blood glucose monitoring.

MATERIALS AND METHODS

This pilot, cross-sectional, observational study was conducted using a validated questionnaire among adult male and female diabetes patients performing self blood glucose monitoring at home. Diabetes patients with complications and juvenile diabetes patients were excluded.

RESULTS

Out of 153 patients surveyed, only 37 (24.1%) (20 males, 17 females) patients were aware and have been following self blood glucose monitoring appropriately. About 116 (75.8%) (64 males, 52 females) of patients were devoid of adequate knowledge and did not practice self blood glucose monitoring in a proper way. Ninety eight (64.05%) accepted that they self titrate their anti diabetic medicines based on self monitoring.

CONCLUSION

Self monitoring of blood glucose should be encouraged and patients should be taught importance of following correct steps and tracking of self monitoring by physician or diabetes educator.

Controlled synthesis, bioimaging and toxicity assessments in strong red emitting Mn2+ doped NaYF4:Yb3+/Ho3+ nanophosphors

Rare earth, Yb³⁺/Ho³⁺ doped NaYF₄ nanophosphors co-doped with Mn²⁺ showed enhanced red emission under NIR irradiation and were successfully used for cancer cell imaging.

Estimation of Specific Salivary Enzymatic Biomarkers in Individuals with Gingivitis and Chronic Periodontitis: A Clinical and Biochemical Study

BACKGROUND

Host response to periodontal disease includes the release of different enzymes from stromal, epithelial or inflammatory cells. The enzymes which are produced from these cells are associated with cell injury and cell death like: Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Alkaline phosphatase (ALP) and Blood urea nitrogen (BUN). Normal enzymatic activity of these enzymes is necessary for healthy functioning of gingiva and periodontium. The aim of the study is to estimate the levels of enzymes AST, ALT, ALP and BUN and to correlate the level of estimated enzymes with that of clinical parameters in the saliva of Healthy subjects, Gingivitis patients and patients with chronic periodontitis.

METHODS

The study included a total of 40 male subjects within the age group of 21 to 50 years, and examined the activity of enzymes AST, ALT, ALP and BUN in saliva spectrophotometrically and compared their values between healthy subjects, gingivitis and chronic periodontitis patients. Clinical parameters like OHI - S (Oral hygiene index - Simplified, SBI (Sulcus Bleeding Index), PPD (Probing Pocket Depth), CAL (Clinical Attachment Level), and PI (Periodontal Index) were recorded.

RESULTS

Obtained results showed statistically significant increases of activity of AST, ALT, ALP, and BUN in saliva from patients with periodontal disease (p<0.001) in relation to gingivitis and control groups. There was also an increase in periodontal parameters with an increase in salivary enzymes.

CONCLUSION

The present study shows that the salivary enzyme activity can be used as biomarkers to determine periodontal tissue damage, which may be useful in diagnosis, prognosis and evaluation of post therapy effects in periodontal disease.

Physiologically Based Pharmacokinetic Modeling of Fluorescently Labeled Block Copolymer Nanoparticles for Controlled Drug Delivery in Leukemia Therapy

A physiologically based pharmacokinetic (PBPK) model was developed that describes the concentration and biodistribution of fluorescently labeled nanoparticles in mice used for the controlled delivery of dexamethasone in acute lymphoblastic leukemia (ALL) therapy. The simulated data showed initial spikes in nanoparticle concentration in the liver, spleen, and kidneys, whereas concentration in plasma decreased rapidly. These simulation results were consistent with previously published in vivo data. At shorter time scales, the simulated data predicted decrease of nanoparticles from plasma with concomitant increase in the liver, spleen, and kidneys before decaying at longer timepoints. Interestingly, the simulated data predicted an unaccounted accumulation of about 50% of the injected dose of nanoparticles. Incorporation of an additional compartment into the model justified the presence of unaccounted nanoparticles in this compartment. Our results suggest that the proposed PBPK model can be an excellent tool for prediction of optimal dose of nanoparticle-encapsulated drugs for cancer treatment.

Hematogenous macrophage depletion reduces the fibrotic scar and increases axonal growth after spinal cord injury

Spinal cord injury (SCI) leads to formation of a fibrotic scar that is inhibitory to axon regeneration. Recent evidence indicates that the fibrotic scar is formed by perivascular fibroblasts, but the mechanism by which they are recruited to the injury site is unknown. Using bone marrow transplantation in mouse model of spinal cord injury, we show that fibroblasts in the fibrotic scar are associated with hematogenous macrophages rather than microglia, which are limited to the surrounding astroglial scar. Depletion of hematogenous macrophages results in reduced fibroblast density and basal lamina formation that is associated with increased axonal growth in the fibrotic scar. Cytokine gene expression analysis after macrophage depletion indicates that decreased Tnfsf8, Tnfsf13 (tumor necrosis factor superfamily members) and increased BMP1-7 (bone morphogenetic proteins) expression may serve as anti-fibrotic mechanisms. Our study demonstrates that hematogenous macrophages are necessary for fibrotic scar formation and macrophage depletion results in changes in multiple cytokines that make the injury site less fibrotic and more conducive to axonal growth.

Disruption of Runx1 and Runx3 leads to bone marrow failure and leukemia predisposition due to transcriptional and DNA repair defects

The RUNX genes encode transcription factors involved in development and human disease. RUNX1 and RUNX3 are frequently associated with leukemias, yet the basis for their involvement in leukemogenesis is not fully understood. Here, we show that Runx1;Runx3 double-knockout (DKO) mice exhibited lethal phenotypes due to bone marrow failure and myeloproliferative disorder. These contradictory clinical manifestations are reminiscent of human inherited bone marrow failure syndromes such as Fanconi anemia (FA), caused by defective DNA repair. Indeed, Runx1;Runx3 DKO cells showed mitomycin C hypersensitivity, due to impairment of monoubiquitinated-FANCD2 recruitment to DNA damage foci, although FANCD2 monoubiquitination in the FA pathway was unaffected. RUNX1 and RUNX3 interact with FANCD2 independently of CBFβ, suggesting a nontranscriptional role for RUNX in DNA repair. These findings suggest that RUNX dysfunction causes DNA repair defect, besides transcriptional misregulation, and promotes the development of leukemias and other cancers.

Pressure Dependence of Chlorine NQR in Strontium Chlorate and Barium Chlorate Monohydrate

The pressure dependence of the 35Cl-NQR frequencies in barium chlorate monohydrate and strontium chlorate, has been investigated up to 7000 kg cm-2. Ba(ClO3)2 · H2O shows a single 35Cl-NQR line at 29.337 MHz (T = 297 K, p = 1 bar). ν(35Cl) increases linearly with pressure in the range studied, with (1/ν )(∂ν/∂p)T = + 0.409 x 10-6 kg-1 cm2 which is much smaller than observed in NaClO3 and KCIO3. Sr(ClO3)2 also gave a single 35Cl-NQR frequency at 20.105 MHz (T = 297 K, p = 1 bar). The pressure dependence is very small and negative in this case. The data in both cases have been analysed to obtain the volume dependence of the torsional frequency. It is pointed out that explicit pressure effects on the electric field gradient have to be taken into account to provide an explanation for the observed pressure dependence of ν (35Cl).

Molecular Complexes of Macrocyclic Polyethers with Fluoranil

Fluoranil forms weak 1:1 molecular complexes with both benzene substituted and nonbenzenoid macrocyclic ethers. 19FMR shifts have been used for the evaluation of association constants. The infrared and 1HMR data of the complexes reveal relative orientations of the molecules in the complexes.

HP1α mediates defective heterochromatin repair and accelerates senescence in Zmpste24-deficient cells

Heterochromatin protein 1 (HP1) interacts with various proteins, including lamins, to play versatile functions within nuclei, such as chromatin remodeling and DNA repair. Accumulation of prelamin A leads to misshapen nuclei, heterochromatin disorganization, genomic instability, and premature aging in Zmpste24-null mice. Here, we investigated the effects of prelamin A on HP1α homeostasis, subcellular distribution, phosphorylation, and their contribution to accelerated senescence in mouse embryonic fibroblasts (MEFs) derived from Zmpste24(-/-) mice. The results showed that the level of HP1α was significantly increased in Zmpste24(-/-) cells. Although prelamin A interacted with HP1α in a manner similar to lamin A, HP1α associated with the nuclease-resistant nuclear matrix fraction was remarkably increased in Zmpste24(-/-) MEFs compared with that in wild-type littermate controls. In wild-type cells, HP1α was phosphorylated at Thr50, and the phosphorylation was maximized around 30 min, gradually dispersed 2 h after DNA damage induced by camptothecin. However, the peak of HP1α phosphorylation was significantly compromised and appeared until 2 h, which is correlated with the delayed maximal formation of γ-H2AX foci in Zmpste24(-/-) MEFs. Furthermore, knocking down HP1α by siRNA alleviated the delayed DNA damage response and accelerated senescence in Zmpste24(-/-) MEFs, evidenced by the rescue of the delayed γ-H2AX foci formation, downregulation of p16, and reduction of senescence-associated β-galactosidase activity. Taken together, these findings establish a functional link between prelamin A, HP1α, chromatin remodeling, DNA repair, and early senescence in Zmpste24-deficient mice, suggesting a potential therapeutic strategy for laminopathy-based premature aging via the intervention of HP1α.

Clinical nanomedicine: a solution to the chemotherapy conundrum in pediatric leukemia therapy

Although chemotherapy-based treatment of leukemia has tremendously improved survival rates in children, induction of treatment-related side effects is a major concern in clinical oncology. The development of nanotechnology-based drug delivery techniques to target clinically approved anticancer agents specifically to leukemic cells should diminish toxic side effects. This review aims to address the rational design of nanotherapeutics in treating hematologic malignancies with a focus on acute lymphoblastic leukemia (ALL)--the most prominent form of pediatric cancer.

Prevalence of dental fluorosis among primary school children in rural areas of chidambaram taluk, cuddalore district, Tamil Nadu, India

Background:

Fluorosis is one of the common but major emerging areas of research in the tropics. It is considered endemic in 17 states of India. However, the Cuddalore district of Tamil Nadu is categorised as a fluorosis non-endemic area. But clinical cases of dental fluorosis were reported in the field practice area of Department of Community Medicine, Rajah Muthiah Medical College, Annamalai University, Chidambaram. Since dental fluorosis has been described as a biomarker of exposure to fluoride, we assessed the prevalence and severity of dental fluorosis among primary school children in the service area.

Materials and Methods:

Children studying in six primary schools of six villages in the field practice area of Rural Health Centre of Faculty of Medicine, Annamalai University, Chidambaram, were surveyed. Every child was clinically examined at the school by calibrated examiners with Dean's fluorosis index recommended by WHO (1997). Chi-square test, Chi-square trend test and Spearman's rank correlation coefficient test were used for statistical analysis.

Results:

Five hundred and twenty-five 5- to 12-year-old school children (255 boys and 270 girls) were surveyed. The overall dental fluorosis prevalence was found to be 31.4% in our study sample. Dental fluorosis increased with age P < 0.001, whereas gender difference was not statistically significant. Aesthetically objectionable dental fluorosis was found in 2.1% of the sample. Villages Senjicherry, Keezhaperambai and Kanagarapattu revealed a community fluorosis index (CFI) score of 0.43, 0.54 and 0.54 with 5.6%, 4.8% and 1.4% of objectionable dental fluorosis, respectively. Correlation between water fluoride content and CFI values in four villages was noted to be positively significant.

Conclusion:

Three out of six villages studied were in ‘borderline’ public health significance (CFI score 0.4-0.6). A well-designed epidemiological investigation can be undertaken to evaluate the risk factors associated with the condition in the study region.

Comparison of the salivary and the serum nitric oxide levels in chronic and aggressive periodontitis: a biochemical study

BACKGROUND AND OBJECTIVES

Nitric oxide (NO) is a ubiquitous intercellular messenger molecule with important cardiovascular, neurological, and immune functions. In addition, it has been postulated that the pharmacological inhibition of NO or its actions may be therapeutically valuable in the disease management. The levels of nitric oxide may provide clues about the severity and the state of the underlying disease process. It could be an inflammatory biomarker that may enable clinicians to direct the environmentally based prevention or treatment programmes and to establish whether NO plays a role in the pathogenesis of periodontitis or not. Hence, the aim of the present study was to evaluate the salivary and the serum levels of NO in generalized chronic and aggressive periodontitis. The Study Design: Unstimulated whole saliva and serum samples were collected from a total of 60 subjects who were in the age group of 18-45 years, who participated in this study. They were divided into three equal groups with 20 subjects in each group; group A (healthy controls), group B (chronic periodontitis) and group C (aggressive periodontitis). The clinical parameters were assessed, based on the oral hygiene index simplified (OHI-S), the gingival index (GI), the probing pocket depth and the clinical attachment loss (CAL). A biochemical analysis was performed to evaluate and compare the salivary and the serum nitric oxide levels of the above groups. Statistical Analysis and Results: The statistical comparisons were done under the Griess Reaction. There were statistically significant salivary and serum levels of NO in the groups of periodontitis (group B and C) as compared to those in the healthy controls (group A). A significant positive correlation was found between the values of the salivary and the serum NO levels in chronic and aggressive periodontitis.

CONCLUSION

Nitric oxide is a potent modulator of the inflammatory disease processes and under pathological conditions, NO has damaging effects. As there is a paucity in the studies which have compared chronic and aggressive periodontitis, this study paved an interest for combining the serum and the salivary analysis in comparing the levels of nitric oxide in chronic and aggressive periodontitis.

Involvement of estrogen receptor β in maintenance of serotonergic neurons of the dorsal raphe

The serotonergic neurons of the dorsal raphe (DR) nucleus in the CNS are involved in fear, anxiety and depression. Depression and anxiety occur quite frequently in postmenopausal women, but estrogen replacement to correct these CNS disorders is at present not favored because estrogen carries with it an increased risk for breast cancer. Serotonin synthesis, release and reuptake in the DR are targets of pharmaceuticals in the treatment of depression. In the present study we have examined by immunohistochemistry, the expression of two nuclear receptors, that is, the estrogen receptors ERα and ERβ. We found that ERβ but not ERα is strongly expressed in the DR and there is no sex difference and no change with ageing in the number of tryptophan hydroxylase (TPH)-positive neurons in the DR of wild-type (WT) mice. However, in ovariectomized (OVX) WT and in ERβ(-/-) mice, there was a marked reduction in the number of TPH-positive normal-looking neurons and a marked increase in TPH-positive spindle-shaped cells. These neuronal changes were prevented in mice 1-3 weeks (but not 10 weeks) after OVX by the selective ERβ agonist, LY3201, given as continuous release pellets for 3 days. The ERβ agonist had no effects on glucose homeostasis. Thus, the onset of action of the ERβ agonist is rapid but there is a limited window in time after estrogen loss when the drug is useful. We conclude that, rather than estradiol, ERβ agonists could be useful pharmaceuticals in maintaining functional DR neurons to treat postmenopausal depression.

Femoroacetabular impingement and comparison of radiological indexes: a study on 50 cases

To study the asphericity of femoral head in femoroacetabular impingement using radiological indices such as alpha angle and triangular index, and to compare the alpha angle and triangular index measured in the radiograph and MRI. The study was conducted prospectively from January 2008 to June 2009 on 50 consecutive patients of suspected cam-type FAI hip, reporting to orthopedics outpatients department of Postgraduate Institute of Medical Education and Research. Radiograph of the affected hip was taken, and then alpha angle and triangular index are measured and compared. The mean alpha angle in anteroposterior view was measured as 75° ± 10°, and the mean in lateral view was 740 ± 80. In MRI the mean alpha angle was 79° ± 9°. The mean triangular index in radiograph was 2.9 ± 1.2. In MRI the mean triangular index was 2.6 ± 0.8. Frog-leg lateral view is sufficient for the diagnosis of the cam-type femoroacetabular impingement. But MRI is required in cases, where surgical intervention is planned to rule out other pathological condition and for decision making.

'Relax and Repair' to restrain aging

The maintenance of genomic integrity requires the precise identification and repair of DNA damage. Since DNA is packaged and condensed into higher order chromatin, the events associated with DNA damage recognition and repair are orchestrated within the layers of chromatin. Very similar to transcription, during DNA repair, chromatin remodelling events and histone modifications act in concert to 'open' and relax chromatin structure so that repair proteins can gain access to DNA damage sites. One such histone mark critical for maintaining chromatin structure is acetylated lysine 16 of histone H4 (AcH4K16), a modification that can disrupt higher order chromatin organization and convert it into a more 'relaxed' configuration. We have recently shown that impaired H4K16 acetylation delays the accumulation of repair proteins to double strand break (DSB) sites which results in defective genome maintenance and accelerated aging in a laminopathy-based premature aging mouse model. These results support the idea that epigenetic factors may directly contribute to genomic instability and aging by regulating the efficiency of DSB repair. In this article, the interplay between epigenetic misregulation, defective DNA repair and aging is discussed.

Modified step-cut osteotomy for post-traumatic cubitus varus: our experience with 14 children

BACKGROUND

Lateral closing wedge osteotomy is a commonly described procedure for correcting cosmetically unacceptable post-traumatic cubitus varus deformity in children. However, complications like residual deformity, lateral prominence, loss of fixation and ulnar nerve palsies commonly contribute to poor outcomes with such an osteotomy.

PATIENTS AND METHODS

Fourteen children (11 boys and three girls) presenting a mal-united extension type supracondylar fracture of the humerus with an average age of 9.07 years (6-14 years) were operated around 3.6 years (1.5-7 years) after the injury using a modified step-cut osteotomy. The average follow-up period was 2.1 years (1-4 years). Objective assessment included measurement of preoperative and postoperative lateral prominence index, carrying angle and range of elbow motion. Results were graded excellent, good or poor as per the Oppenheim criteria.

RESULTS

There were eight excellent, five good and one poor result. A residual varus of more than 10° was seen in the single patient with poor result. None of the patients showed a prominent lateral humeral condyle or formation of hypertrophic scar. Our results were comparable to the published results of the classical lateral closing wedge osteotomy in terms of elbow motion and correction of deformity.

CONCLUSION

A modified step-cut osteotomy is a safe and simple procedure which prevents lateral prominence and leads to good or excellent outcomes in most of the patients. The step-cut osteotomy procedure, mentioned here, might be beneficial over the conventional lateral closing wedge osteotomy in certain aspects like the lateral humeral condyle prominence, scar acceptibility and cosmesis. However, the apparent aforementioned advantages of this osteotomy over the conventional lateral closing wedge osteotomy needs to be further evaluated and confirmed on the basis of large, prospective randomised controlled trials.