KMT2D acetylation by CREBBP reveals a cooperative functional interaction at enhancers in normal and malignant germinal center B cells.

Heterozygous inactivating mutations of the KMT2D methyltransferase and the CREBBP acetyltransferase are among the most common genetic alterations in B cell lymphoma and co-occur in 40 to 60% of follicular lymphoma (FL) and 30% of EZB/C3 diffuse large B cell lymphoma (DLBCL) cases, suggesting they may be coselected. Here, we show that combined germinal center (GC)-specific haploinsufficiency of Crebbp and Kmt2d synergizes in vivo to promote the expansion of abnormally polarized GCs, a common preneoplastic event. These enzymes form a biochemical complex on select enhancers/superenhancers that are critical for the delivery of immune signals in the GC light zone and are only corrupted upon dual Crebbp/Kmt2d loss, both in mouse GC B cells and in human DLBCL. Moreover, CREBBP directly acetylates KMT2D in GC-derived B cells, and, consistently, its inactivation by FL/DLBCL-associated mutations abrogates its ability to catalyze KMT2D acetylation. Genetic and pharmacologic loss of CREBBP and the consequent decrease in KMT2D acetylation lead to reduced levels of H3K4me1, supporting a role for this posttranslational modification in modulating KMT2D activity. Our data identify a direct biochemical and functional interaction between CREBBP and KMT2D in the GC, with implications for their role as tumor suppressors in FL/DLBCL and for the development of precision medicine approaches targeting enhancer defects induced by their combined loss.

Emerging therapeutic potential of graviola and its constituents in cancers.

Cancer remains a leading cause of death in the USA and around the world. Although the current synthetic inhibitors used in targeted therapies have improved patient prognosis, toxicity and development of resistance to these agents remain a challenge. Plant-derived natural products and their derivatives have historically been used to treat various diseases, including cancer. Several leading chemotherapeutic agents are directly or indirectly based on botanical natural products. Beyond these important drugs, however, a number of crude herbal or botanical preparations have also shown promising utility for cancer and other disorders. One such natural resource is derived from certain plants of the family Annonaceae, which are widely distributed in tropical and subtropical regions. Among the best known of these is Annona muricata, also known as soursop, graviola or guanabana. Extracts from the fruit, bark, seeds, roots and leaves of graviola, along with several other Annonaceous species, have been extensively investigated for anticancer, anti-inflammatory and antioxidant properties. Phytochemical studies have identified the acetogenins, a class of bioactive polyketide-derived constituents, from the extracts of Annonaceous species, and dozens of these compounds are present in different parts of graviola. This review summarizes current literature on the therapeutic potential and molecular mechanism of these constituents from A.muricata against cancer and many non-malignant diseases. Based on available data, there is good evidence that these long-used plants could have both chemopreventive and therapeutic potential. Appropriate attention to safety studies will be important to assess their effectiveness on various diseases caused or promoted by inflammation.

Axed MUC4 (MUC4/X) aggravates pancreatic malignant phenotype by activating integrin-ß1/FAK/ERK pathway.

Alternative splicing is evolving as an eminent player of oncogenic signaling for tumor development and progression. Mucin 4 (MUC4), a type I membrane-bound mucin, is differentially expressed in pancreatic cancer (PC) and plays a critical role in its progression and metastasis. However, the molecular implications of MUC4 splice variants during disease pathogenesis remain obscure. The present study delineates the pathological and molecular significance of a unique splice variant of MUC4, MUC4/X, which lacks the largest exon 2, along with exon 3. Exon 2 encodes for the highly glycosylated tandem repeat (TR) domain of MUC4 and its absence creates MUC4/X, which is devoid of TR. Expression analysis from PC clinical samples revealed significant upregulation of MUC4/X in PC tissues with most differential expression in poorly differentiated tumors. In vitro studies suggest that overexpression of MUC4/X in wild-type-MUC4 (WT-MUC4) null PC cell lines markedly enhanced PC cell proliferation, invasion, and adhesion to extracellular matrix (ECM) proteins. Furthermore, MUC4/X overexpression leads to an increase in the tumorigenic potential of PC cells in orthotopic transplantation studies. In line with these findings, doxycycline-induced expression of MUC4/X in an endogenous WT-MUC4 expressing PC cell line (Capan-1) also displayed enhanced cell proliferation, invasion, and adhesion to ECM, compared to WT-MUC4 alone, emphasizing its direct involvement in the aggressive behavior of PC cells. Investigation into the molecular mechanism suggested that MUC4/X facilitated PC tumorigenesis via integrin-ß1/FAK/ERK signaling pathway. Overall, these findings revealed the novel role of MUC4/X in promoting and sustaining the oncogenic features of PC.

Genetic variants of mucins: unexplored conundrum.

Alternative gene splicing, occurring ubiquitously in multicellular organisms can produce several protein isoforms with putatively different functions. The enormously extended genomic structure of mucin genes characterized by the presence of multiple exons encoding various domains may result in functionally diverse repertoire of mucin proteins due to alternative splicing. Splice variants (Svs) and mutations in mucin genes have been observed in various cancers and shown to participate in cancer progression and metastasis. Although several mucin Svs have been identified, their potential functions remain largely unexplored with the exception of the Svs of MUC1 and MUC4. A few studies have examined the expression of MUC1 and MUC4 Svs in cancer and indicated their potential involvement in promoting cancer cell proliferation, invasion, migration, angiogenesis and inflammation. Herein we review the current understanding of mucin Svs in cancer and inflammation and discuss the potential impact of splicing in generating a functionally diverse repertoire of mucin gene products. We also performed mutational analysis of mucin genes across five major cancer types in International Cancer Genome Consortium database and found unequal mutational rates across the panel of cancer-associated mucins. Although the functional role of mucins in the pathobiology of various malignancies and their utility as diagnostic and therapeutic targets remain undisputed, these attributes need to be reevaluated in light of the potentially unique functions of disease-specific genetic variants of mucins. Thus, the expressional and functional characterization of the genetic variants of mucins may provide avenues to fully exploit their potential as novel biomarkers and therapeutic targets.

Secretory Trefoil Factor 1 (TFF1) promotes gemcitabine resistance through chemokine receptor CXCR4 in Pancreatic Ductal Adenocarcinoma.

Gemcitabine is the first-line treatment option for patients with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, the frequent adoption of resistance to gemcitabine by cancer cells poses a significant challenge in treating this aggressive disease. In this study, we focused on analyzing the role of trefoil factor 1 (TFF1) in gemcitabine resistance in PDAC. Analysis of PDAC TCGA and cell line datasets indicated an enrichment of TFF1 in the gemcitabine-resistant classical subtype and suggested an inverse correlation between TFF1 expression and sensitivity to gemcitabine treatment. The genetic ablation of TFF1 in PDAC cells enhanced their sensitivity to gemcitabine treatment in both in vitro and in vivo tumor xenografts. The biochemical studies revealed that TFF1 contributes to gemcitabine resistance through enhanced stemness, increasing migration ability of cancer cells, and induction of anti-apoptotic genes. We further pursued studies to predict possible receptors exerting TFF1-mediated gemcitabine resistance. Protein-protein docking investigations with BioLuminate software revealed that TFF1 binds to the chemokine receptor CXCR4, which was supported by real-time binding analysis of TFF1 and CXCR4 using SPR studies. The exogenous addition of TFF1 increased the proliferation and migration of PDAC cells through the pAkt/pERK axis, which was abrogated by treatment with a CXCR4-specific antagonist AMD3100. Overall, the present study demonstrates the contribution of the TFF1-CXCR4 axis in imparting gemcitabine resistance properties to PDAC cells.

Comparing the Psychological Problems Among the Health Care Workers Across Two Waves of SARS-CoV-2 (COVID-19) Pandemic: An Observational Study from India.

OBJECTIVE: Literature investigating the change in psychological problems of the health care workers (HCWs) throughout the coronavirus disease (COVID-19) pandemic is lacking. We aimed at comparing the psychological problems and attitudes toward work among HCWs over two waves of the COVID-19 pandemic in India. METHODS: A survey was conducted involving HCWs (n = 305, first wave, 2020; n = 325, second wave, 2021). Participants' demographic and professional and psychological characteristics (using attitude toward COVID-19 questionnaire [ATCQ]; Depression, Anxiety, and Stress Scale - 21 Items and impact of event scale - 22) were recorded. The unpaired t-test/chi-squared test was used for comparison. RESULTS: Significant improvements (χ2(1) = 7.3 to 45.6, P < 0.05) in level of depression (42.2% vs 9.6%), anxiety (41.3% vs 16.3%), stress (30.1% vs 6.7%), event-related stress symptoms (31.2% vs 27%), work-related stress (89.8% vs 76.8%), and stigma (25.9% vs 22.8, though marginally significant) were found among the participants of the second wave (vs first wave). However, on subgroup analysis, allied-HCWs (housekeeping staff and security personnel) reported lesser concerns over the domains of the ATCQ vis-a-viz frontline-HCWs (doctors and nurses). CONCLUSION: This improvement could be attributed to greater awareness about the illness, better coping skills, vaccination, and so forth; however, more research is warranted to investigate these determinants.

Feasibility and Effectiveness of Telecounseling on the Psychological Problems of Frontline Healthcare Workers Amidst COVID-19: A Randomized Controlled Trial from Central India.

BACKGROUND: Preliminary reports suggest that during the COVID-19 pandemic, telecounseling could be an effective model of psychological intervention for the frontline healthcare workers (fHCW) with psychological problems. Literature is sparse in this area, particularly from low- and middle-income countries, including India. We aimed to investigate the feasibility and the effectiveness of telecounseling (vs. general education) on the psychological problems of the fHCW over three time-points (baseline vs. end-of-session and at two and four weeks after the intervention). METHODS: The study followed a single-blind, active arm versus general education, parallel-group randomized control design, with participant allocation in 1:1. Active healthcare workers (HCWs) with mild- to-severe or clinically concerning scores on any of the sub-scales of Depression, Anxiety and Stress Scale (DASS-21) or Impact of Event Scale-Revised (IES-R; represented by higher scores) were included, while those with known psychiatric illness were excluded. Chi-square and Mann-Whitney U test and linear-mixed effect model (group-, time, and group by time-effect) were used for analysis. RESULTS: There were no baseline group differences (telecounseling group, active arm, n = 9; general education group, control arm, n = 10). A significant time-effect (P = 0.044 to <.001) was found on DASS-21 on intention-to-treat analysis. Per-protocol analysis, additionally, found a significant group effect on Impact of Event Scale-Revised (IES-R; P = 0.036). A significant random effect of the participants was also found (P <.001). CONCLUSION: Telecounseling could be a feasible and scalable model of psychological interventions for the fHCW with psychological problems, albeit with some feasibility challenges.

Study of respiratory viruses and their coinfection with bacterial and fungal pathogens in acute exacerbation of chronic obstructive pulmonary diseases.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) develop acute exacerbations (AE), with varying natural history. The exacerbation is triggered by infection, leading to increased morbidity and mortality. The study on infectious aetiology of AECOPD is largely restricted to only viral or only bacterial aetiology. There are no studies from India that have investigated multiple viral, bacterial, and fungal associations from the same group of patients. This prospective study was conducted over 2 years to estimate the incidence and profile of viral infections in AECOPD patients, their coinfection with other bacterial and fungal agents, and association of the type and pattern of infective agent with the clinical severity. MATERIALS AND METHODS: Seventy-four AECOPD cases were included in the study. Multiplex polymerase chain reaction was performed from nasopharyngeal swab using Fast Track Diagnostics Respiratory Pathogens 21 Plus Kit. Ziehl-Neelsen (ZN) stain, Modified ZN, and potassium hydroxide (KOH) mount were performed for Mycobacteria, Nocardia, and fungal elements. Bacterial cultures and fungal cultures were done as per the standard techniques. Serum samples were tested for Mycoplasma and Chlamydia pneumoniae immunoglobulin M enzyme-linked immunosorbent assay. RESULTS: The number of AECOPD events involving only viral infection, only bacterial infection, bacterial-viral coinfection, and no infection were 43 (58.1%), 32 (43.2%), 20 (27%), and 19 (25.7%), respectively. Influenza A virus was the most common virus (22/43, 51%) identified. In 26 patients, monoviral infections were found, and in 17 patients, polyviral infections were identified, the most common pattern being influenza A and B virus, followed by human rhinovirus and human parainfluenza. The most common bacteria isolated were Pseudomonas aeruginosa (9/32,28%) followed by Acinetobacter baumanii and Klebsiella pneumoniae (7/32, 21%). Among the viral-bacterial coinfection, human coronavirus NL63 infection was always associated with a bacterial infection. CONCLUSION: This information on the various viral and bacterial etiologies of respiratory infections in AECOPD in this part of India will improve the understanding of the management of AECOPD using a timely institution of antivirals and reduce the overuse of antibiotics and the implementation of routine influenza vaccination.

Secretory Mucin 5AC Promotes Neoplastic Progression by Augmenting KLF4-Mediated Pancreatic Cancer Cell Stemness.

Secreted mucin 5AC (MUC5AC) is the most abundantly overexpressed member of the mucin family during early pancreatic intraepithelial neoplasia stage I (PanIN-I) of pancreatic cancer. To comprehend the contribution of Muc5ac in pancreatic cancer pathology, we genetically ablated it in an autochthonous murine model (KrasG12D; Pdx-1cre, KC), which mirrors the early stages of pancreatic cancer development. Neoplastic onset and the PanIN lesion progression were significantly delayed in Muc5ac knockout (KrasG12D; Pdx-1 cre; Muc5ac-/-, KCM) animals with a 50% reduction in PanIN-2 and 70% reduction in PanIN-3 lesions compared with KC at 50 weeks of age. High-throughput RNA-sequencing analysis from pancreatic tissues of KCM animals revealed a significant decrease in cancer stem cell (CSC) markers Aldh1a1, Klf4, EpCAM, and CD133. Furthermore, the silencing of MUC5AC in human pancreatic cancer cells reduced their tumorigenic propensity, as indicated by a significant decline in tumor formation frequency by limiting dilution assay upon subcutaneous administration. The contribution of MUC5AC in CSC maintenance was corroborated by a significant decrease in tumor burden upon orthotopic implantation of MUC5AC-depleted pancreatic cancer cells. Mechanistically, MUC5AC potentiated oncogenic signaling through integrin αvß5, pSrc (Y416), and pSTAT3 (Y705). Phosphorylated STAT3, in turn, upregulated Klf4 expression, thereby enriching the self-renewing CSC population. A strong positive correlation of Muc5ac with Klf4 and pSTAT3 in the PanIN lesions of KC mouse pancreas reinforces the crucial involvement of MUC5AC in bolstering the CSC-associated tumorigenic properties of Kras-induced metaplastic cells, which leads to pancreatic cancer onset and progression. SIGNIFICANCE: This study elucidates that de novo expression of MUC5AC promotes cancer cell stemness during Kras-driven pancreatic tumorigenesis and can be targeted for development of a novel therapeutic regimen.

ST6GalNAc-I promotes lung cancer metastasis by altering MUC5AC sialylation.

Lung cancer (LC) is the leading cause of cancer-related mortality. However, the molecular mechanisms associated with the development of metastasis are poorly understood. Understanding the biology of LC metastasis is critical to unveil the molecular mechanisms for designing targeted therapies. We developed two genetically engineered LC mouse models KrasG12D/+ ; Trp53R172H/+ ; Ad-Cre (KPA) and KrasG12D/+ ; Ad-Cre (KA). Survival analysis showed significantly (P = 0.0049) shorter survival in KPA tumor-bearing mice as compared to KA, suggesting the aggressiveness of the model. Our transcriptomic data showed high expression of N-acetylgalactosaminide alpha-2, 6-sialyltransferase 1 (St6galnac-I) in KPA compared to KA tumors. ST6GalNAc-I is an O-glycosyltransferase, which catalyzes the addition of sialic acid to the initiating GalNAc residues forming sialyl Tn (STn) on glycoproteins, such as mucins. Ectopic expression of species-specific p53 mutants in the syngeneic mouse and human LC cells led to increased cell migration and high expression of ST6GalNAc-I, STn, and MUC5AC. Immunoprecipitation of MUC5AC in the ectopically expressing p53R175H cells exhibited higher affinity toward STn. In addition, ST6GalNAc-I knockout (KO) cells also showed decreased migration, possibly due to reduced glycosylation of MUC5AC as observed by low STn on the glycoprotein. Interestingly, ST6GalNAc-I KO cells injected mice developed less liver metastasis (P = 0.01) compared to controls, while colocalization of MUC5AC and STn was observed in the liver metastatic tissues of control mice. Collectively, our findings support the hypothesis that mutant p53R175H mediates ST6GalNAc-I expression, leading to the sialyation of MUC5AC, and thus contribute to LC liver metastasis.

Odyssey of trefoil factors in cancer: Diagnostic and therapeutic implications.

Trefoil factors 1, 2, and 3 (TFFs) are a family of small secretory molecules involved in the protection and repair of the gastrointestinal tract (GI). TFFs maintain and restore epithelial structural integrity via transducing key signaling pathways for epithelial cell migration, proliferation, and invasion. In recent years, TFFs have emerged as key players in the pathogenesis of multiple diseases, especially cancer. Initially recognized as tumor suppressors, emerging evidence demonstrates their key role in tumor progression and metastasis, extending their actions beyond protection. However, to date, a comprehensive understanding of TFFs' mechanism of action in tumor initiation, progression and metastasis remains obscure. The present review discusses the structural, functional and mechanistic implications of all three TFF family members in tumor progression and metastasis. Also, we have garnered information from studies on their structure and expression status in different organs, along with lessons from their specific knockout in mouse models. In addition, we highlight the emerging potential of using TFFs as a biomarker to stratify tumors for better therapeutic intervention.

A phase I study of weekly doxorubicin and oral topotecan for patients with relapsed or refractory small cell lung cancer (SCLC): A Fred and Pamela Buffet Cancer Center Clinical Trials Network study.

BACKGROUND: Relapsed/refractory small cell lung cancer (SCLC) has a poor prognosis, with no good options. We evaluated a novel combination of topotecan and doxorubicin, providing sequential topoisomerase I and II inhibition, in this setting. MATERIALS AND METHODS: Adult patients (>19 years) with relapsed/refractory SCLC, who had received at least one prior chemotherapy regimen were eligible. Patients received escalating doses of oral topotecan on days 1-5 of each three week cycle (maximum - 5 cycles). The dosing cohorts were: 0.85 mg/m2, 1.05 mg/m2, 1.35 mg/m2, 1.65 mg/m2 and 2.30 mg/m2. All patients received weekly doxorubicin 20 mg/m2 intravenously starting day 6 of the first cycle and continued weekly for a maximum of 15 weeks. In the absence of pre-specified dose limiting toxicities (DLT), patients were enrolled serially to escalated dose level cohorts. RESULTS: Twenty-two patients were enrolled, of which 20 were evaluable. Median age was 61 years; 74% were male and 95% were Caucasian. Hematologic side effects were the most common adverse events. There were no therapy-related Grade 5 toxicities. Incidence of DLT based on cohorts were: DL2: 1/6 (Grade 4 thrombocytopenia), DL3: 1/6 (AST elevation) and DL4: 2/4 (Grade 4 thrombocytopenia). Response rate was 20% (4/20) and disease control rate (SD + PR) was 36%. The median progression free and overall survival were 3.6 months and 6 months, respectively. CONCLUSIONS: The combination of topotecan and doxorubicin was safe and effective in relapsed/refractory SCLC. The maximum tolerated dose of oral topotecan was 1.35 mg/m2 when given concurrently with weekly doxorubicin.

Trefoil factor(s) and CA19.9: A promising panel for early detection of pancreatic cancer.

BACKGROUND: Trefoil factors (TFF1, TFF2, and TFF3) are small secretory molecules that recently have gained significant attention in multiple studies as an integral component of pancreatic cancer (PC) subtype-specific gene signature. Here, we comprehensively investigated the diagnostic potential of all the member of trefoil family, i.e., TFF1, TFF2, and TFF3 in combination with CA19.9 for detection of PC. METHODS: Trefoil factors (TFFs) gene expression was analyzed in publicly available cancer genome datasets, followed by assessment of their expression in genetically engineered spontaneous mouse model (GEM) of PC (KrasG12D; Pdx1-Cre (KC)) and in human tissue microarray consisting of normal pancreas adjacent to tumor (NAT), precursor lesions (PanIN), and various pathological grades of PC by immunohistochemistry (IHC). Serum TFFs and CA19.9 levels were evaluated via ELISA in comprehensive sample set (n = 362) comprised of independent training and validation sets each containing benign controls (BC), chronic pancreatitis (CP), and various stages of PC. Univariate and multivariate logistic regression and receiver operating characteristic curves (ROC) were used to examine their diagnostic potential both alone and in combination with CA19.9. FINDINGS: The publicly available datasets and expression analysis revealed significant increased expression of TFF1, TFF2, and TFF3 in human PanINs and PC tissues. Assessment of KC mouse model also suggested upregulated expression of TFFs in PanIN lesions and early stage of PC. In serum analyses studies, TFF1 and TFF2 were significantly elevated in early stages of PC in comparison to benign and CP control group while significant elevation in TFF3 levels were observed in CP group with no further elevation in its level in early stage PC group. In receiver operating curve (ROC) analyses, combination of TFFs with CA19.9 emerged as promising panel for discriminating early stage of PC (EPC) from BC (AUCTFF1+TFF2+TFF3+CA19.9 = 0.93) as well as CP (AUCTFF1+TFF2+TFF3+CA19.9 = 0.93). Notably, at 90% specificity (desired for blood-based biomarker panel), TFFs combination improved CA19.9 sensitivity by 10% and 25% to differentiate EPC from BC and CP respectively. In an independent blinded validation set, the combination of TFFs and CA19.9 (AUCTFF1+TFF2+TFF3+CA19.9 = 0.82) also improved the overall efficacy of CA19.9 (AUCCA19.9 = 0.66) to differentiate EPC from CP proving unique biomarker capabilities of TFFs to distinguish early stage of this deadly lethal disease. INTERPRETATION: In silico, tissue and serum analyses validated significantly increased level of all TFFs in precursor lesions and early stages of PC. The combination of TFFs enhanced sensitivity and specificity of CA19.9 to discriminate early stage of PC from benign control and chronic pancreatitis groups.

Development and characterization of carboxy-terminus specific monoclonal antibodies for understanding MUC16 cleavage in human ovarian cancer.

MUC16 is overexpressed in ovarian cancer and plays important roles in invasion and metastasis. Previously described monoclonal antibodies against cell surface expressed MUC16 recognize the N-terminal tandemly repeated epitopes present in cancer antigen 125 (CA125). MUC16 is cleaved at a specific location, thus, releasing CA125 into the extracellular space. Recent reports have indicated that the retained carboxy-terminal (CT) fragment of MUC16 might play an important role in tumorigenicity in diverse types of cancers. However, limited data is available on the fate and existence of CT fragment on the surface of the cancer cell. Herein, we characterize two monoclonal antibodies (mAbs) showing specificity to the retained juxtamembrane region of MUC16. For the first time, we demonstrate that MUC16 is cleaved in ovarian cancer cells (NIH:OVCAR-3 [OVCAR-3]) and that the cleaved MUC16 subunits remain associated with each other. Immunohistochemical analyses on different grades of ovarian tumor tissues indicated differential reactivity of CA125 and MUC16 CT mAbs. The CA125 (M11) mAb detected 32/40 (80%), while the CT mAb (5E6) detected 33/40 (82.5%) of total ovarian cancer cases. For serous and serous papillary cases, the CA125 (M11) mAb stained 27/31 cases (87%), while CT mAb (5E6) stained 29/31 cases (93.5%). The CT mAb(s) accurately predict expression of MUC16 since their epitopes are not tandemly repeated and their reactivity may not be dependent on O-linked glycosylation. These antibodies can serve as valuable reagents for understanding MUC16 cleavage and may also serve as potential therapeutic agents for treatment of ovarian cancer.

Afatinib radiosensitizes head and neck squamous cell carcinoma cells by targeting cancer stem cells.

The dismal prognosis of locally advanced and metastatic squamous cell carcinoma of the head and neck (HNSCC) is primarily due to the development of resistance to chemoradiation therapy (CRT). Deregulation of Epidermal Growth Factor Receptor (EGFR) signaling is involved in HNSCC pathogenesis by regulating cell survival, cancer stem cells (CSCs), and resistance to CRT. Here we investigated the radiosensitizing activity of the pan-EGFR inhibitor afatinib in HNSCC in vitro and in vivo. Our results showed strong antiproliferative effects of afatinib in HNSCC SCC1 and SCC10B cells, compared to immortalized normal oral epithelial cells MOE1a and MOE1b. Comparative analysis revealed stronger antitumor effects with afatinib than observed with erlotinib. Furthermore, afatinib enhanced in vitro radiosensitivity of SCC1 and SCC10B cells by inducing mesenchymal to epithelial transition, G1 cell cycle arrest, and the attenuating ionizing radiation (IR)-induced activation of DNA double strand break repair (DSB) ATM/ATR/CHK2/BRCA1 pathway. Our studies also revealed the effect of afatinib on tumor sphere- and colony-forming capabilities of cancer stem cells (CSCs), and decreased IR-induced CSC population in SCC1 and SCC10B cells. Furthermore, we observed that a combination of afatinib with IR significantly reduced SCC1 xenograft tumors (median weight of 168.25 ± 20.85 mg; p = 0.05) compared to afatinib (280.07 ± 20.54 mg) or IR alone (324.91 ± 28.08 mg). Immunohistochemical analysis of SCC1 tumor xenografts demonstrated downregulation of the expression of IR-induced pEGFR1, ALDH1 and upregulation of phosphorylated γH2AX by afatinib. Overall, afatinib reduces tumorigenicity and radiosensitizes HNSCC cells. It holds promise for future clinical development as a novel radiosensitizer by improving CSC eradication.

Emerging potential of natural products for targeting mucins for therapy against inflammation and cancer.

Deregulated mucin expression is a hallmark of several inflammatory and malignant pathologies. Emerging evidence suggests that, apart from biomarkers, these deregulated mucins are functional contributors to the pathogenesis in inflammation and cancer. Both overexpression and downregulation of mucins in various organ systems is associated with pathobiology of inflammation and cancer. Restoration of mucin homeostasis has become an important goal for therapy and management of such disorders has fueled the quest for selective mucomodulators. With improved understanding of mucin regulation and mechanistic insights into their pathobiological roles, there is optimism to find selective non-toxic agents capable of modulating mucin expression and function. Recently, natural compounds derived from dietary sources have drawn attention due to their anti-inflammatory and anti-oxidant properties and low toxicity. Considerable efforts have been directed towards evaluating dietary natural products as chemopreventive and therapeutic agents; identification, characterization and synthesis of their active compounds; and improving their delivery and bioavailability. We describe the current understanding of mucin regulation, rationale for targeting mucins with natural products and discuss some natural products that modulate mucin expression and functions. We further discuss the approaches and parameters that should guide future research to identify and evaluate selective natural mucomodulators for therapy.

In vitro dissolution study of atorvastatin binary solid dispersion.

The aim of the present study was to improve the solubility and dissolution rate of atorvastatin (ATV), a slight water-soluble drug, by solid dispersion (SD) technique using a hydrophilic carrier Poloxamer 188 (POL188). Physical mixing (PM) and solvent evaporation (SE) method were used to prepare ATV-SD where different drug-carrier ratios were used. Prepared formulations were characterized in their solid state by solubility study; differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy which demonstrated changes in the formulations supporting the improved solubility. Percent content of POL188 in the SD matrix was found to play the pivotal role in the improvement of dissolution property of ATV. In case of PM, highest enhancement in drug release was found for 1:3 ratio (P < 0.05, ANOVA Single factor) whereas in case of SE, 3:0.5 ratio of ATV-POL188 resulted the maximum enhancement in ATV release (P < 0.05, ANOVA Single factor). Analysis of dissolution data of optimized formula indicated the best fitting with Peppas-Korsmeyer model and the drug release kinetics was fickian diffusion. In conclusion, binary SD prepared by both PM and SE technique using POL188 could be considered as a simple, efficient method to prepare ATV solid dispersions with significant improvement in the dissolution rate.