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Conformational switch of a peptide provides a novel strategy to design peptide loaded porous organic polymer for pyroptosis pathway mediated cancer therapy
No full textWhile peptide-based drug development is extensively explored, this strategy has limitations due to rapid excretion from the body (or shorter half-life in the body) and vulnerability to protease-mediated degradation. To overcome these limitations, a novel strategy for the development of a peptide-based anticancer agent is introduced, utilizing the conformation switch property of a chameleon sequence stretch (PEP1) derived from a mycobacterium secretory protein, MPT63. The selected peptide is then loaded into a new porous organic polymer (PG-DFC-POP) synthesized using phloroglucinol and a cresol derivative via a condensation reaction to deliver the peptide selectively to cancer cells. Utilizing ensemble and single-molecule approaches, this peptide undergoes a transition from a disordered to an alpha-helical conformation, triggered by the acidic environment within cancer cells that is demonstrated. This adopted alpha-helical conformation resulted in the formation of proteolysis-resistant oligomers, which showed efficient membrane pore-forming activity selectively for negatively charged phospholipids accumulated in cancer cell membranes. The experimental results demonstrated that the peptide-loaded PG-DFC-POP-PEP1 exhibited significant cytotoxicity in cancer cells, leading to cell death through the Pyroptosis pathway, which is established by monitoring numerous associated events starting from lysosome membrane damage to GSDMD-induced cell membrane demolition. This novel conformational switch-based drug design strategy is believed to have great potential in endogenous environment-responsive cancer therapy and the development of future drug candidates to mitigate cancers
Sex bias in treatment abandonment of childhood cancer in India
No full textObjectives
To explore the magnitude of sex bias and determinants of treatment abandonment (TA) in childhood cancer in India.
Methods
Individual data of children (0–19 y) registered between January 1, 2017 and July 31, 2022, was compiled. TA was defined as defaulting curative intent treatment ≥4 wk. Defaulting treatment irrespective of intent ≥4 wk was defined as Treatment Default (TD). The primary outcome was the proportion of male-to-female children with TA. Secondary outcomes included the proportion of male-to-female children with upfront TA, TA at relapse, TD, TD-p (TD only in the palliative setting). The impact of clinico-demographic factors on TA was analysed using multivariable regression and propensity score matching (PSM).
Results
Three thousand two hundred eighty four patients were analysed. The overall male-to-female ratio (MFR) was 2.08 (95% CI 1.94–2.24). Of 2906 patients treated with curative intent, 415 (14·3%) abandoned treatment. TA was higher in females than males (16·4% vs. 13·3%; p = 0·022) with adjusted MFR of 0·81 (0·66–0·98). The adjusted MFR of TA for treatment-naïve and relapsed patients and TD were 0·73 (0·59–0·91), 1·13 (0·65–1·96) and 0·84 (0·71–1·00) respectively. Sex independently predicted TA on multivariable analysis. However, on PSM analysis including socio-economic variables, lower maternal education predicted higher TA in children with cancer (10·1% vs. 6%, p = 0·015).
Conclusions
Child sex predicted TA in childhood cancer in India with more females abandoning treatment. Maternal education is a more crucial factor predicting TA over child sex, when socio-economic factors were considered. Hence, policies promoting female education and gender equality may mitigate sex-based gaps in childhood cancer care
Sequence effects on the thermal <i>cis</i>–<i>trans</i> isomerization of side‐chain stearate‐containing azobenzene polymers.
No full textPhotochromic azobenzenes undergo light-mediated trans–cis isomerization. The cis isomer reverts to the trans isomer thermally. To investigate the effect of different monomer sequences on the thermal stability of cis-azobenzene, a series of copolymers, namely, block, and random structures containing stearic acid and azobenzene moieties as their side chains have been synthesized through reversible addition–fragmentation chain transfer (RAFT) polymerization. In this study, we investigate the photoisomerization of the trans and cis forms of the polymers and also the thermal reversal of the cis-azobenzene photochromic systems. The isomerization data revealed significant differences in the isomerization timescales between the polymers and the corresponding monomer. It was observed that the local polarity around the azobenzene units within a polymer was significantly influenced by the chain segment depending on whether it was in the vicinity of the hydrophobic alkyl chains or other azobenzene units. This local environment of the azobenzene units regulates the stabilization of the transition states during the cis–trans thermal isomerization, consequently affecting the half-life of the cis isomer
A chemically engineered water-soluble block copolymer for redox responsive SO<sub>2</sub> release in antibacterial therapy.
No full textSulfur dioxide (SO2) has emerged as a promising gasotransmitter for various therapeutic applications, including antibacterial activities. However, the potential of polymeric SO2 donors for antimicrobial activities remains largely unexplored. Herein, we report a water-soluble, redox-responsive, SO2-releasing amphiphilic block copolymer poly(polyethylene glycol methyl ether methacrylate) (PPEGMA)-b-poly(2-((2,4-dinitrophenyl)sulfonamido)ethyl methacrylate (PM)) (BCPx) to investigate their antibacterial properties. BCPx contains hydrophilic polyethylene glycol (PEG) pendants and a hydrophobic SO2-releasing PM block, facilitating the formation of self-assembled nanoparticles (BCPxNp) in an aqueous medium, studied by critical aggregation concentration (CAC) measurements, dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). BCPxNp exhibits sustained SO2 release up to 12 h in the presence of glutathione (GSH), with a yield of 30–80% of theoretical SO2 release. In vitro antibacterial studies unveil the outstanding antibacterial activity of BCP3Np against Gram-positive bacteria Bacillus subtilis, as evidenced by FESEM and live/dead cell fluorescence assay. We further elucidate the antibacterial mechanism through reactive oxygen species (ROS) generation studies. Overall, the polymer exhibits excellent biocompatibility at effective antimicrobial concentrations and provides insights into the design of a new class of SO2-releasing polymeric antibacterial agents
Management of extraocular retinoblastoma: icmr consensus guidelines
No full textRetinoblastoma (RB) is the most common intraocular malignancy of childhood. Advanced stage presentation of RB is common in low middle-income countries (LMICs) due to lack of awareness, social taboos associated with enucleation, seeking alternative conservative treatment options, and poor accessibility to health care. Over the last few decades, there have been significant advancements in the management of extraocular RB (EORB) which have improved outcomes and helped in minimizing treatment-related toxicities. The incorporation of multimodality approaches including chemotherapy, surgery, and radiotherapy (RT) has shown promising results; however, prognosis remains poor especially in LMICs. In this article, authors have discussed the ICMR consensus guidelines on the management of EORB, including metastatic RB
Determinants of tumor necrosis and its impact on outcome in patients with Localized osteosarcoma uniformly treated with a response adapted regimen without high dose Methotrexate– A retrospective institutional analysis
No full textPurpose
Response to neoadjuvant chemotherapy in form of tumor necrosis predicts outcome in osteosarcoma; although response-adapted treatment escalation failed to improve outcome among patients treated with high-dose methotrexate-based (HDMTx) chemotherapy. This study aimed to identify factors predicting tumor necrosis and its impact on survival among patients with non-metastatic osteosarcoma treated with a response-adapted non-HDMTx regimen.
Methods
A retrospective single-institutional study was conducted among non-metastatic osteosarcoma patients treated with neoadjuvant therapy between 2004–2019. Patients were treated uniformly with three cycles of neoadjuvant cisplatin/doxorubicin. Post-operatively, patients with favourable necrosis (≥90 %) received 3 cycles of cisplatin/doxorubicin, while patients with poor necrosis (<90 %) received escalated treatment with alternating six cycles of cisplatin/doxorubicin and ifosfamide/etoposide. Propensity score matching (PSM) analyses were conducted to ascertain independent impact of necrosis on event-free survival (EFS) and overall survival (OS).
Results
Of 594 registered osteosarcoma patients, 280 patients (median age 17 years; male 67.1 %) were included for analysis. 73 patients (26.1 %) achieved favourable necrosis. Patients with smaller tumor size (≤10 cm) (aOR = 2.28; p = 0.030), lower serum alkaline phosphatase (≤450 IU/L) (aOR = 2.10; p = 0.035), and who had surgery earlier (<115 days) (aOR = 2.28; p = 0.016) were more likely to have favourable necrosis. On 1:2 PSM analysis, patients not achieving favourable necrosis demonstrated inferior EFS (HR = 2.68; p = 0.003) and OS (HR = 3.42; p = 0.003).
Conclusions
Patients of osteosarcoma with smaller tumor, lower serum alkaline phosphatase and earlier surgery are more likely to achieve favourable necrosis. Tumor necrosis independently predicts outcome in osteosarcoma, and response-adapted treatment escalation fails to overcome the adverse impact of poor necrosis in non-HDMTx based regimen
Flow Cytometry-Based Detection of Minimal/Measurable Residual Disease Predicts Survival Outcomes in Pediatrics, Adolescents, and Young Adults With T-acute Lymphoblastic Leukemia
No full textBackground: Measurable/minimal residual disease (MRD) is considered the single most powerful high-risk factor in acute leukemia, including T-cell acute lymphoblastic leukemia (T-ALL). In this study, we evaluated the impact of flow cytometry (FC)-based detection of MRD on survival outcomes in pediatrics, adolescents, and young adults (AYA) with T-ALL.
Methods: We included 139 patients, 88 pediatric patients between the ages of one and 14 years, and 51 AYA patients between 15 and 39 years of age, over a period of three years and were treated with the Indian Collaborative Childhood Leukemia Group (ICiCLe) protocol. MRD assessment was performed on post-induction (PI) bone marrow aspirate samples using a 10-color 11-antibody MRD panel on a Gallios instrument (Beckman Coulter, Miami, FL, USA). MRD value > 0.01% was considered positive. PI-MRD status was available in 131 patients.
Results: The five-year event-free survival (5-year EFS) in PI-MRD positive patients was inferior to those of negative patients (13.56% vs 79.06%), which was statistically significant (P < 0.001). However, the five-year overall survival (5-year OS) did not show any statistically significant difference between PI-MRD positive and negative T-ALL patients (92.93% vs 94.28%). The hazard ratio (HR) for 5-year EFS and MRD positivity was 8.03 (p-value < 0.0001). HR for 5-year EFS and early T-cell precursor ALL (ETP-ALL) was 2.63 (p = -0.02).
Conclusions: PI-MRD detected using FC is a strong predictive factor of inferior survival outcomes in pediatrics, AYA patients with T-ALL. PI-MRD positivity can be used to modify the treatment of T-ALL patients, especially in resource-constrained developing countries where molecular tests are not widely available
Implementation of the recommended immunohistochemistry algorithm for classification of peripheral <scp>T</scp>‐cell lymphoma, not otherwise specified into the prognostically significant <scp>GATA3</scp> and <scp>TBX21</scp> subtypes
No full textIntroduction
Current molecular research has shown the several oncogenic pathways that give rise to the peripheral T-cell lymphoma, not otherwise defined (PTCL, NOS) subtypes, which alter prognosis and might have predictive value. This study was conducted to assess the immunohistochemistry (IHC) algorithm by Amador et al for the subtyping of PTCL, NOS and determine its applicability in relation to the clinicopathological profile.
Methods
This study included 43 patients with PTCL, NOS diagnosis. Following the use of IHC for the transcription factors GATA3, TBX21, CCR4, and CXCR3, two pathologists subtyped the samples. Comprehensive clinicopathological correlation was carried out.
Results
Applying the algorithm of Amador et al., cases were classified into GATA3 (20), TBX21 (15), and unclassified (8) subtypes. No significant association with clinical parameters of subtypes or CD4/ CD8 positivity was observed. Although a higher proportion of cases in the TBX21 subgroup showed a polymorphic population compared with the GATA3 subgroup, which had a monomorphic population, no significant p-value (0.111) was observed. Two Lennert lymphomas were classified into the GATA3 subgroup. Multivariate analysis showed no significant difference in overall survival (p-value = 0.105) and progression-free survival (p-value = 0.0509) between IHC-defined subtypes; trends indicate that overall survival and progression-free survival are worse in the GATA3 subgroup.
Conclusion
Although the algorithm is reproducible, a proportion of cases remains unclassifiable and may require additional investigation and gene expression profiling. The GATA3 subgroup was found to have a monomorphic population with a poor overall prognosis and thus requires a larger sample size for validation
Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) International Registry: Tagraxofusp Cohort Treatment Results
No full textBackground: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an orphan malignancy defined by the WHO as affection fewer than 65 per 100,000 people and by the U.S. FDA as affecting less than 200,000 people in the U.S.. The BPDCN international registry was launched in July 2022 with the aim to create a large database for this rare disease, to generate data-driven diagnostic and treatment recommendations, and provide real-world evidence.
Aim:The aim of this abstract is to evaluate the outcomes of BPDCN patients treated with tagraxofusp, an immunotoxin targeting CD123 that was approved by the U.S. FDA in December 2018 and the European EMA in January 2021 for the treatment of BPDCN.
Methods: The registry collects retrospective and prospective data of patients diagnosed with BPDCN after January 1st, 2010. We assessed baseline characteristics, response to treatment and outcomes of BPDCN patients who received tagraxofusp.
Results: As of June 2024, 70 patients from 13 countries (USA, Egypt, Canada, Italy, Georgia, Turkey, UK, India, Armenia, Iraq, Kuwait, Cyprus and Romania) were included in the registry. Among those, 22 patients (from USA, UK and Italy) have received treatment with tagraxofusp. Seventeen patients were treated with tagraxofusp as a first line therapy and 5 patients as a second line. The median age was 76years (range 40-87) with only one female patient. Fifteen patients had received tagraxofusp before the U.S. FDA approval in the setting of clinical trials. In the first line therapy setting, the overall response rate was 82% (14/17 patients) where 9 patients had a complete response (CR), 5 pts partial response (PR), 2 stable disease (SD), and one patient was not evaluable(no information was available). Of the 9 CR patients, 2 passed away from other reasons besides BPDCN, one was lost to follow up, the other 6 relapsed. Median time to relapse was 3 months. Among the relapsed patients, 4 experienced progressive or stable disease on subsequent chemotherapy regimens, 2 were treated with HyperCVAD followed allogeneic stem cell transplantation (allo-SCT) and were alive at last follow-up. Of the 7 patients with PR and SD as first line therapy, 6 experienced progressive disease, 1 patient who was treated with HyperCVAD followed by allo-SCT was alive at last follow-up. None of 5 patients treated with tagraxofusp as a second line therapy experienced CR, two patients experienced short SD, the other three progressive disease. At the last follow-up information was available for 19 of 22 patients of which 4 were alive.
Conclusion: Tagraxofusp yields high response rates with more than 50% CR in the upfront setting; however, the relapse rates without allo-SCT remains high. This therapy is currently only available in selected countries and only 3 out of the 13 countries participating in this registry reported its use. The treatment strategy of BPDCN should be a total therapy approach incorporating novel agents like tagraxofusp with intrathecal chemotherapy and allo-SCT to prevent the relapse
Endoprosthesis vs. Nail-cement spacer application for reconstruction after oncologic proximal humeral resection: is there a difference in functional outcome?
No full textBackground
The proximal humerus is a common site for primary malignant and benign aggressive bone tumors, necessitating wide resection and subsequent skeletal defect reconstruction. Various reconstruction options include osteoarticular allografts, autografts, endoprosthesis, nail-cement spacer, reverse shoulder arthroplasty, and allograft-prosthesis composites. However, there is no consensus on the optimal reconstruction method. This study aims to compare functional outcomes and complications between these two methods.
Methods
A total of 40 patients with proximal humerus tumors who underwent endoprosthesis or nail-cement spacer reconstruction between March 2012 and December 2020 were included. The mean follow-up in the study was 31.37 +/− 12 months. Demographic and clinical data were collected, and functional outcomes were assessed using the Musculoskeletal Tumor Society 93 scoring system and the Disabilities of the Arm, Shoulder, and Hand questionnaire. Complications and oncological outcomes were recorded.
Results
Both groups were similar in terms of demographic and clinical variables. Endoprosthesis reconstruction demonstrated significantly better active shoulder forward flexion compared to nail-cement spacer (45.8 vs. 25.2 degrees) (P = .015). Endoprosthesis group also exhibited greater active shoulder internal rotation (68.25 vs. 63.25 degrees) (P = .004). No statistically significant differences were observed in overall functional outcomes. Complications, including radial nerve palsy and infection, were comparable between groups, with one case of spacer loosening.
Conclusion
Both endoprosthesis and nail-cement spacer reconstruction provide comparable functional outcomes and complication rates following proximal humerus tumor resection. Nail-cement spacer offers a cost-effective alternative for patients in resource-constrained settings