Breast cancer survival in India across 11 geographic areas under the National Cancer Registry Programme.

BACKGROUND: Population-based cancer survival is a key indicator for assessing the effectiveness of cancer control by a health care system in a specific geographic area. Breast cancer is the most common cancer among women in India, accounting for over one quarter of all female cancers. The objective of this study was to estimate the 5-year survival of female patients who were diagnosed with breast cancer between 2012 and 2015 from the existing Population-Based Cancer Registries (PBCRs) in India. METHODS: In total, 17,331 patients who had breast cancer diagnosed between 2012 and 2015 from 11 PBCRs were followed until June 30, 2021. Active methods were used to track the vital status of registered breast cancer cases. The study conducted survival analysis by calculating the difference between the date of first diagnosis and the date of death or censoring to estimate observed survival and relative survival using the actuarial survival approach and the Ederer-II approach, respectively. RESULTS: The 5-year age-standardized relative survival (95% confidence interval [CI]) of patients with breast cancer was 66.4% (95% CI, 65.5%-67.3%). Mizoram (74.9%; 95% CI, 68.1%-80.8%), Ahmedabad urban (72.7%; 95% CI, 70.3%-74.9%), Kollam (71.5%; 95% CI, 69.2%-73.6%), and Thiruvananthapuram (69.1%; 95% CI, 67.0%-71.2%) had higher survival rates than the national average. Conversely, Pasighat had the lowest survival rate (41.9%; 95% CI, 14.7%-68.6%). The 5-year observed survival rates for localized, regional, and distant metastasis in the pooled PBCRs were 81.0%, 65.5%, and 18.3%, respectively. CONCLUSIONS: The overall disparity in survival rates was observed across 11 PBCRs, with lower survival rates reported in Manipur, Tripura, and Pasighat. Therefore, it is imperative to implement comprehensive cancer control strategies widely throughout the country.

Modulating the acetylation of α-tubulin by LncRNAs and microRNAs helps in the progression of cancer.

Malignant tumor cells go through morphological and gene expression alterations, including rearrangement of cytoskeleton proteins that promote invasion and metastasis. Microtubules form a major cytoskeleton component that plays a significant role in regulating multiple cellular activities and function depending on the presence of posttranslational modification (PTM). Acetylation is a type of PTM that generally occurs in the lysine 40 region of α-tubulin and is known to be critically associated with cancer metastasis. Current evidence demonstrates that noncoding RNAs, such as long noncoding RNA (lncRNA) and microRNA (or miRNA), which are correlated with gene regulation modulate the expression of acetylated tubulin in the development and metastasis of cancer. This review provides an overview about the role of lncRNA and miRNA in regulation of tubulin acetylation in various types of cancer.

Enhanced olfactory memory detection in trap-design Y-mazes allows the study of imperceptible memory traces in Drosophila.

The neural basis of behavior is identified by systematically manipulating the activity of specific neurons and screening for loss or gain of phenotype. Therefore, robust, high-scoring behavioral assays are necessary for determining the neural circuits of novel behaviors. We report a simple Y-maze design for Drosophila olfactory learning and memory assay. Memory scores in our Y-mazes are considerably better and longer-lasting than scores obtained with commonly used T-mazes. Our results suggest that trapping flies to an odor choice in a Y-maze could improve scores. We postulated that the improved scores could reveal previously undetectable memory traces, enabling the study of underlying neural mechanisms. Indeed, we identified unreported protein synthesis-dependent long-term memories (LTMs), reinforced by ingestion of (1) an aversive compound and (2) a sweet but nonnutritious sugar, both 24 h after training. We also used Y-mazes to probe how using a greater reward may change memory dynamics. Our findings predict that a greater sugar reward may extend existing memory traces or reinforce additional novel ones.

Diagnostic accuracy of Liver Imaging Reporting and Data System locoregional treatment response criteria: a systematic review and meta-analysis.

OBJECTIVE: There is increasing adoption of Liver Imaging Reporting and Data System (LI-RADS) treatment response (LR-TR) criteria. However, there is still a relative lack of evidence evaluating the performance of these criteria. We performed this study to assess the diagnostic accuracy of LI-RADS LR-TR criteria. METHODS: A thorough search of PubMed, Embase, Scopus, and Cochrane Central Register of Controlled Trials for studies reporting diagnostic accuracy of LI-RADS LR-TR criteria was conducted through 30 June 2020. The meta-analytic summary of sensitivity, specificity, and diagnostic odds ratio of LI-RADS LR-TR criteria was computed using explant histopathology as the reference standard. The quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. RESULTS: Four studies were found eligible for meta-analysis. The total number of LR-TR observations was 462 (240 patients, 82.5% males). Different locoregional therapies (LRTs), including bland embolization, chemoembolization, radiofrequency ablation, and microwave ablation, had been used. The mean time interval between LRT and liver transplantation ranged from 181 to 219 days. There was a moderate to good inter-reader agreement for LR-TR criteria. The pooled sensitivity and specificity of LR-TR criteria for viable disease were 62% (95% CI, 49-74%; I2 = 69%) and 87% (95% CI, 76-93%; I2 = 57%), respectively. The pooled diagnostic odds ratio and area under the curve were 9.83 (95% CI, 5.34-18.08; I2 = 19%) and 0.80. CONCLUSIONS: LI-RADS LR-TR criteria have acceptable diagnostic performance for the diagnosis of viable tumor after LRT. Well-designed prospective studies evaluating criteria of equivocal lesions and effect of different LRTs should be performed. KEY POINTS: • The pooled sensitivity and specificity of LI-RADS LR-TR criteria for the diagnosis of viable tumor were 62% and 87%, respectively. • The pooled diagnostic odds ratio and area under the curve were 9.83 and 0.80. • LR-TR criteria had a moderate to good inter-reader agreement.

Plasma Proteomic Profiling in Hypertrophic Cardiomyopathy Patients before and after Surgical Myectomy Reveals Post-Procedural Reduction in Systemic Inflammation.

Left Ventricular Outflow Tract (LVOT) obstruction occurs in approximately 70% of Hypertrophic Cardiomyopathy (HCM) patients and currently requires imaging or invasive testing for diagnosis, sometimes in conjunction with provocative physiological or pharmaceutical stimuli. To identify potential biomarkers of LVOT obstruction, we performed proteomics profiling of 1305 plasma proteins in 12 HCM patients with documented LVOT obstruction, referred for surgical myectomy. Plasma was collected at the surgical preoperative visit, approximately one month prior to surgery and then at the post-surgical visit, approximately 3 months later. Proteomic profiles were generated using the aptamer-based SOMAscan assay. Principal Component Analysis using the highest statistically significant proteins separated all preoperative samples from all postoperative samples. Further analysis revealed a set of 25 proteins that distinguished the preoperative and postoperative states with a paired t-test p-value of <0.01. Ingenuity Pathway analysis facilitated the generation of protein interaction networks and the elucidation of key upstream regulators of differentially expressed proteins, such as interferon-γ, TGF-ß1, and TNF. Biological pathways affected by surgery included organ inflammation, migration, and motility of leukocytes, fibrosis, vasculogenesis, angiogenesis, acute coronary events, endothelial proliferation, eicosanoid metabolism, calcium flux, apoptosis, and morphology of the cardiovascular system. Our results indicate that surgical relief of dynamic outflow tract obstruction in HCM patients is associated with unique alterations in plasma proteomic profiles that likely reflect improvement in organ inflammation and physiological function.

Dual-Arm Nanocapsule Targets Neuropilin-1 Receptor and Microtubule: A Potential Nanomedicine Platform.

A multiarm nanomedicine template has been designed following bottom-up approach, which target neuropilin-1 (Nrp-1) receptor of cancer cells. Through this venture, we discovered that cucurbit [6] uril (CB [6]) binds with tubulin close to binding pocket of vinblastine site and perturbs tubulin polymerization. To increase the specificity of gold nanoparticle (GNP) toward Nrp-1-rich cancer cells, we further modified this GNP with Nrp-1 receptor-specific short peptide (CGNKRTR). Remarkably, we found an interesting self-assembly process upon addition of curcumin into the CB [6] and peptide-functionalized GNP, leading to the formation of a spherical nanocapsule (CGNP·Cur). It can deliver and release significantly higher amounts of anticancer drug curcumin in Nrp-1-rich cancer cells. It causes microtubule depolymerization and significant tumor regression in Nrp-1 overexpressed mice melanoma model. These interesting findings show that nanocapsule has high potential to develop a powerful anticancer nanomedicine and help in its preclinical validation.

Spatial Position Regulates Power of Tryptophan: Discovery of a Major-Groove-Specific Nuclear-Localizing, Cell-Penetrating Tetrapeptide.

Identification of key amino acids is required for development of efficient cell-penetrating peptides (CPPs) and has tremendous implications in medicine. Extensive research work has enlightened us about the importance of two amino acids, arginine and tryptophan, in cell penetration. Here, we present a top-down approach to show how spatial positions of two tryptophans regulate the cellular entry and nuclear localization. This enables us to develop short, non-toxic tetrapeptides with excellent potential for cell penetration and nuclear localization. Among them, Glu-Thr-Trp-Trp (ETWW) emerges as the most promising. Results suggest that it enters into cancer cells following an endocytic pathway and binds at the major groove of nuclear DNA, where successive tryptophan plays major role. We subsequently show that it is not a P-glycoprotein substrate and is non-toxic to PC12-derived neurons, suggesting its excellent potential as a CPP. Furthermore, its potential as a CPP is validated in multi-cellular 3D cell culture (spheroid) and in in vivo mice model. This study provides major fundamental insights about the positional importance of tryptophan and opens new avenues toward the development of next-generation CPPs and major-groove-specific anticancer drugs.

Designed Tetrapeptide Interacts with Tubulin and Microtubule.

Microtubules regulate eukaryotic cell functions, which have tremendous implication in tumor progression. Thus, the design of novel approaches for controlling microtubule function is extremely important. In this manuscript, a novel tetrapeptide Ser-Leu-Arg-Pro (SLRP) has been designed and synthesized from a small peptide library consisting of 14 tetrapeptides, which perturbs microtubule function through interaction in the "anchor region". We have studied the role of peptides on microtubule function on a chemically functionalized 2D platform. Interestingly, we have found that SLRP binds with tubulin and inhibits the kinesin-driven microtubule motility on a kinesin-immobilized chemically functionalized 2D platform. Further, this peptide modulator interacts with intracellular tubulin/microtubule and depolymerizes the microtubule networks. These interesting findings of perturbation of microtubule function both on engineered platforms and inside the cell by this small peptide modulator inspired us to study the effect of this tetrapeptide on cancer cell proliferation. We found that the novel tetrapeptide modulator causes moderate cytotoxicity to the human breast cancer cell (MCF-7 cell), induces the apoptotic death of MCF-7 cell, and activates the tumor suppressor proteins p53 and cyclin-dependent kinase inhibitor 1 (p21). To the best of our knowledge, this is the shortest peptide discovered, which perturbs microtubule function both on an engineered 2D platform and inside the cell.

Layered reward signalling through octopamine and dopamine in Drosophila.

Dopamine is synonymous with reward and motivation in mammals. However, only recently has dopamine been linked to motivated behaviour and rewarding reinforcement in fruitflies. Instead, octopamine has historically been considered to be the signal for reward in insects. Here we show, using temporal control of neural function in Drosophila, that only short-term appetitive memory is reinforced by octopamine. Moreover, octopamine-dependent memory formation requires signalling through dopamine neurons. Part of the octopamine signal requires the α-adrenergic-like OAMB receptor in an identified subset of mushroom-body-targeted dopamine neurons. Octopamine triggers an increase in intracellular calcium in these dopamine neurons, and their direct activation can substitute for sugar to form appetitive memory, even in flies lacking octopamine. Analysis of the ß-adrenergic-like OCTß2R receptor reveals that octopamine-dependent reinforcement also requires an interaction with dopamine neurons that control appetitive motivation. These data indicate that sweet taste engages a distributed octopamine signal that reinforces memory through discrete subsets of mushroom-body-targeted dopamine neurons. In addition, they reconcile previous findings with octopamine and dopamine and suggest that reinforcement systems in flies are more similar to mammals than previously thought.

Probing the conformational dynamics of photosystem I in unconfined and confined spaces.

The fluorescence dynamics of Photosystem I (PSI) in bulk water and inside a confined environment like a liposome have been investigated using time resolved confocal microscopy. In bulk water, PSI exhibits a major emission peak at ∼680 nm, while in the liposome it exhibits a markedly blue shifted emission maximum at ∼485 nm. This is indicative of conformational changes due to entrapment and emergence of a stressed conformation of PSI inside the liposome. The observed time constants for the fluorescence lifetime of PSI inside the liposome are significantly high as opposed to PSI in bulk water. More interestingly, the fluorescence intensity of PSI in bulk water exhibits strong fluctuations with many high intensity jumps and these are anti-correlated with the fluorescence lifetime of PSI. In contrast, inside the liposome, no such anti-correlated behaviour is observed. We further demonstrated that PSI exhibits at least two conformational states in bulk water, whereas a single conformation is observed inside the liposome, indicating the conformational rigidity and locking of the PSI complex inside a liposome.

Regioselective synthesis of naphthoquinone/naphthoquinol-carbohydrate hybrids by [4 + 2] anionic annulations and studies on their cytotoxicity.

An efficient and regioselective synthetic route to naphthoquinone/naphthoquinol-carbohydrate hybrids has been developed. It is based upon anionic annulation of 3-nucleofugalphthalides with an acrylate appended sugar moiety. In each of the annulations studied, the arene-carbohydrate hybrids were obtained in good to excellent yields. The in vitro cytotoxic activity of the synthetic naphthoquinone/naphthonol-carbohydrate hybrids were evaluated against the human cervical cancer cell line (HeLa), and a few of them were found to exhibit potent anticancer activity against the cell line.

Spectral mapping of 3D multi-cellular tumor spheroids: time-resolved confocal microscopy.

A tumor-like multi-cellular spheroid (3D) differs from a 2D cell in a number of ways. This is demonstrated using time resolved confocal microscopy. Two different tumor spheroids - HeLa (cervical cancer) and A549 (lung cancer) - are studied using 3 different fluorescent dyes - C153 (non-covalent), CPM (covalent) and doxorubicin (non-covalent, anti-cancer drug). The pattern of localization of these three fluorescent probes in the 3D tumor cell exhibits significant differences from that in the conventional 2D cells. For both the cells (HeLa and A549), the total uptake of doxorubicin in the 3D cell is much lower than that in the 2D cell. The uptake of doxorubicin molecules in the A549 spheroid is significantly different compared to the HeLa spheroid. The local polarity (i.e. emission maxima) and solvation dynamics in the 3D tumor cell differ from those in 2D cells. The covalent probe CPM exhibits intermittent fluorescence oscillations in the 1-2 s time scale. This is attributed to redox processes. These results may provide new insights into 3D tumors.

Forequarter Amputation for Malignant Tumours: Tale of Sustained Relevance or Telltale Sign of Doom?

Forequarter amputation (interscapulothoracic amputation) includes surgical removal of an upper limb and the shoulder girdle, including the scapula and a portion of the clavicle. We aim to report about our recent experience of having to resort to this mutilating surgery and the clinicopathological variables in that context. The study was done at a cancer centre in Northeast India. It was an ambispective study design, where the patient cohort who underwent FQA was identified retrospectively from the operative register of major surgeries for the time period 1st June 2020 to 31st May 2022 (24 months), and these patients were followed up prospectively from 1st June 2022 to 31st May 2023 (1 year). The study variables were obtained from the electronic medical records (EMR), the physical case files and the hospital-based cancer registry (HBCR). There were 7 patients who underwent forequarter amputation (FQA) during the two years, and in the same period, 15 patients underwent limb salvage surgery for tumours around the shoulder girdle. This translates to a FQA rate of 31.8%. The male:female ratio of the patients was 3:4. The median age of the patients was 32 years (range 19 to 59 years). The histologies included osteosarcoma (2), chondrosarcoma (2), Ewing's sarcoma (2) and hidradenocarcinoma (1). None of these patients had any distant metastatic disease. Four patients had local disease progression on neoadjuvant chemotherapy. Three of the patients had emergency surgery as a life-saving procedure on account of bleeding from their ulcerated tumours. Two patients had disease which was recurrent and unsalvageable due to the encasement of the neurovascular bundle. The median follow-up was 8 months (range 4 to 18 months). Five patients had distant recurrence with pulmonary metastases (100%) and bone secondaries (14.3%) within a range of 3 to 8 months. None of the patients had any local recurrence. Two patients are on follow-up without any evidence of disease (17 and 18 months respectively). Forequarter amputation is the surgical option when tumours around the shoulder girdle are not amenable to limb-sparing procedures by virtue of their disease extent. These cancers are usually aggressive leading to early distant metastasis.

Real-World Experience of Patient's Compliance and Clinical Outcomes for Trimodality Treatment for Esophageal Cancer: a Study from a Cancer Center in North-East India.

Preoperative chemoradiotherapy is a standard treatment for patients with locally advanced, resectable esophageal cancer. The treatment completion rates impact the survival outcomes (Eyck et al J Clin Oncol 39(18):1995-2004, 2021). Thus, we aimed to estimate the effect of neoadjuvant chemoradiotherapy (NACRT) in terms of treatment completion rates and survival in this subset of patients and bring out the clinical outcomes in that context. This was a retrospective study done at a tertiary cancer center in North-East India. The study period was from 1 January 2018 to 31 December 2021. We included patients diagnosed with locally advanced and resectable esophageal cancer (cT2-3NanyM0) involving the middle and/or lower thoracic esophagus and who were planned for trimodality treatment in the Joint Tumor Board. Out of the 82 patients who were planned for trimodality treatment, all were squamous cell carcinomas. We found that 54.9% of patients completed the entire trimodality treatment. The median age was 56 years (range 34 to 73 years). The male to female ratio was 59:23. Adverse events, of any grade, were seen in 76% of patients who received NACRT. Fatigue (66%) was the most common toxicity. The common hematologic toxicities were neutropenia and anemia (7.3% each). A total of 45 patients (54.9%) were able to complete all the three modalities of treatment. Transthoracic esophagectomy was the preferred approach (84.4%). The site of anastomosis was in the neck of all the patients. Anastomotic leak was seen in 17.7% of patients. Postoperative pulmonary and cardiac complications occurred in 31.1% and 8.9% of patients respectively. The 30-day mortality was 6.7% (three deaths). A pathological complete response was seen in 35.6% among patients who underwent an esophagectomy. R0 resection was achieved in 93.3% of patients. The median overall survival and disease-free survival were 19 months and 17 months respectively. The completion rate of trimodality treatment in the real-world scenario was found to be low in our study, the reasons for which need to be identified and effectively resolved. Oncological outcomes were similar to the published literature.

Crude extract of Ruellia tuberosa L. flower induces intracellular ROS, promotes DNA damage and apoptosis in triple negative breast cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Ruellia tuberosa L. (Acanthaceae) is a weed plant traditionally used in folklore medicine as a diuretic, anti-hypertensive, anti-pyretic, anti-cancerous, anti-diabetic, analgesic, and gastroprotective agent. It has been previously reported that R. tuberosa L. is enriched with various flavonoids, exhibiting significant cytotoxic potential in various cancer models but a detailed study concerning its molecular mechanism is yet to be explored. AIM OF THE STUDY: Exploring and validating R. tuberosa L. flower methanolic extract (RTME) as an anti-cancerous agent as per traditional usage with special emphasis on multi-drug resistant human triple-negative breast cancer (TNBC) and investigating the possible signaling networks and regulatory pathways involved in it. MATERIALS AND METHODS: In this study, RTME was prepared using methanol, and phytochemical analysis was performed through GC-MS. Then, the extract was tested for its anti-cancer potential through in-vitro cytotoxicity assay, clonogenic assay, wound healing assay, ROS generation assay, cell cycle arrest, apoptotic nuclear morphology study, cellular apoptosis study, mitochondrial membrane potential (MMP) alteration study, protein, and gene expressions alteration study. In addition, toxicological status was evaluated in female Balb/C mice, and to check the receptor-ligand interactions, in-silico molecular docking was also conducted. RESULTS: Several phytochemicals were found within RTME through GC-MS, which have been already reported to act as ROS inductive, DNA damaging, cell cycle arresting, and apoptotic agents against cancer cells. Moreover, RTME was found to exhibit significant in-vitro cytotoxicity along with a reduction in colony formation, and inhibition of cell migratory potential. It also induced intracellular ROS, promoted G0/G1 cell cycle arrest, caused mitochondrial membrane potential (MMP) alteration, and promoted cell death. The Western blot and qRT-PCR data revealed that RTME promoted the intrinsic pathway of apoptosis. Furthermore, blood parameters and organ histology on female Balb/C mice disclosed the non-toxic nature of RTME. Finally, an in-silico molecular docking study displayed that the three identified lead phytochemicals in RTME show strong receptor-ligand interactions with the anti-apoptotic Bcl-2 and give a clue to the possible molecular mechanism of the RTME extract. CONCLUSIONS: RTME is a potential source of several phytochemicals that have promising therapeutic potential against TNBC cells, and thus could further be utilized for anti-cancer drug development.

Cyclin D1 inactivation extends proliferation and alters histogenesis in the postnatal mouse retina.

BACKGROUND: The cell-cycle regulator Cyclin D1 is expressed in embryonic retinal progenitor cells (RPCs) and regulates their cell-cycle rate and neurogenic output. We report here that Cyclin D1 also has important functions in postnatal retinal histogenesis. RESULTS: The initial production of Müller glia and bipolar cells was enhanced in Cyclin D1 knockout (Ccnd1(-/-) ) retinas. Despite a steeper than normal rate of depletion of the RPC population at embryonic ages, postnatal Ccnd1(-/-) retinas exhibited an extended window of proliferation, neurogenesis, and gliogenesis. Cyclin D3, normally confined to Müller glia, was prematurely expressed in Ccnd1(-/-) RPCs. However, Cyclin D3 did not compensate for Cyclin D1 in regulating cell-cycle kinetics or neurogenic output. CONCLUSIONS: The data presented in this study along with our previous finding that Cyclin D2 was unable to completely compensate for the absence of Cyclin D1 indicate that Cyclin D1 regulates retinal histogenesis in ways not shared by the other D-cyclins.

Early-Onset Gastric Cancer from a Geographic Area of High Gastric Cancer Incidence in North-East India: a Retrospective Study.

We aim to report about the clinico-pathological characteristics of early-age gastric cancer in North-East India. It is a retrospective and observational study conducted in a tertiary care cancer centre in North-East India. We reviewed physical case records and the hospital electronic medical record system. The study population included all patients of age 40 years or less, with a confirmed diagnosis of gastric adenocarcinoma, who received treatment in the institute. The duration of the study was from 2016 to 2020. Data was collected using a pre-designed proforma, and the results were presented as percentages, ratios, median values and range. A total of 79 patients with early-age gastric cancer were found during the study period. There was female preponderance (45:34). Out of the total, 43% presented in stage IV. Most of them had good performance status (87.3% had ECOG 0-2), and none of them had documented co-morbid illness. Poorly differentiated adenocarcinoma and signet ring cell carcinoma were seen in 36.7% and 25.3% patients, respectively. Only 25 patients (31.6%) underwent definitive surgery, and they had a high nodal burden with a median metastatic lymph nodal ratio of 0.35 (range 0 to 0.91). Out of them, 40% developed systemic recurrence within a short span of time (median time to recurrence being 9.5 months). Peritoneal recurrence was the most common site of failure (80%). Early-age gastric cancer has been associated with aggressive pathological features and poor clinical outcomes in North-East India.

Outcomes of Patients Undergoing Major Surgery for Cancer with COVID-19 in the Postoperative Period.

The aim of our study was to report about the clinical outcomes of patients who underwent major surgery for cancer and developed COVID-19 in the postoperative period. A retrospective and observational study was done in the Surgical Oncology Division of a tertiary care cancer hospital in North-East India. The study period was from 1st April 2020 to 31st December 2021. Patients with a confirmed diagnosis of cancer who underwent a major surgery and developed COVID-19 in the postoperative period, within the same hospital stay were included in the study. Data was obtained from a prospectively maintained database and case records. Descriptive statistics were used to state the results in median values, range and percentages. A total of 22 patients developed COVID-19 in the postoperative period during the study period out of a total of 1402 patients operated during that time period (1.57%). The have been followed up for a median period of 16 months (range 2 to 18 months). The median age at presentation was 50 years (range 25 to 74 years). The incidence of co-morbidities was 27.3%. The median duration of ICU stay was 3 days (range 0 to 9 days) and median duration of hospital stay was 22 days (range 9 to 55 days).. The postoperative mortality rate was 18.2%. COVID-19 in the postoperative period in patients undergoing major abdominal and thoracic surgeries for cancer caused high postoperative mortality and prolonged hospital stay.

The Role of Protein-L-isoaspartyl Methyltransferase (PIMT) in the Suppression of Toxicity of the Oligomeric Form of Aß42, in Addition to the Inhibition of Its Fibrillization.

The oligomeric form of amyloid-ß peptide (Aß42) plays a crucial role in the pathogenesis of Alzheimer's disease (AD) and is responsible for cognitive deficits. The soluble oligomers are believed to be more toxic compared to the fibril form. Protein-L-isoaspartyl methyltransferase (PIMT) is a repair enzyme that converts aberrant isoAsp residues, formed spontaneously on isomerization of normal Asp and Asn residues, back to typical Asp. It was shown to inhibit the fibrillization of Aß42 (containing three Asp residues), and here, we investigate its effect on the size, conformation, and toxicity of Aß42 oligomers (AßO). Far-UV CD indicated a shift in the conformational feature of AßOs from the random coil to ß-sheet in the presence of PIMT. Binding of bis-ANS to different AßOs (obtained using different concentrations of Aß42 monomer) indicated the correlation of size of oligomers to hydrophobicity: the smallest AßO having the highest hydrophobicity is the most toxic. Dynamic light scattering showed an increase in size of AßO with the addition of PIMT, a contrasting role to that on Aß fibril. Assays using PC12-derived neurons showed the neuroprotective role of PIMT against AßO-induced toxicity. Furthermore, we have elaborated on the molecular mechanism of the antifibrillar action of PIMT and how this function is correlated with its enzymatic activity. PIMT has a more pronounced effect on AßO as compared to a small heat shock protein, pointing to its importance for the amelioration of the adverse effect of both Aß42 oligomers and fibrils.

Liposomes Containing Zinc-Based Chemotherapeutic Drug Block Proliferation and Trigger Apoptosis in Breast Cancer Cells.

Platinum-based chemotherapeutic drugs are effective in killing malignant cells but often trigger drug resistance or off-target side effects. Unlike platinum, zinc is used as an endogenous cofactor for several cellular enzymes and may, thus, display increased biocompatibility. In this present study, we have rationally designed and synthesized two substituted phenanthro[9,10-d]imidazole-based ligands L1 and L2 with pyridine and quinoline substitution at the 2 position and their corresponding Zn(II) complexes; (L1)2Zn and (L2)2Zn, which are characterized by standard analytical and spectroscopic methods. (L2)2Zn, but not (L1)2Zn has intrinsic fluorescence, indicating its potential utility in imaging applications. To facilitate cellular uptake, we generated liposomal formations with a phospholipid DMPC (1,2-Dimyristoyl-sn-glycero-3-phosphocholine) through molecular self-assembly. These liposomal formulations Lip-(L1)2Zn and Lip-(L2)2Zn were able to enter breast cancer cells, induce DNA fragmentation, arrest the cell cycle at the G0/G1 phase, decrease proliferation, and promote apoptosis by activating the DNA damage response. Importantly, both Lip-(L1)2Zn and Lip-(L2)2Zn decreased the size of breast cancer cell-based spheroids, indicating they may be capable of suppressing tumor growth. Our work represents an important proof-of-concept exercise demonstrating that successful liposomal formation of phenanthro[9,10-d]imidazole-based Zn(II) complexes with inherent optical properties have great promise for the development of imaging probes and efficient anticancer drugs.