Impact of Remote Symptom Monitoring With Electronic Patient-Reported Outcomes on Hospitalization, Survival, and Cost in Community Oncology Practice: The Texas Two-Step Study.

PURPOSE: There is raising interest to implement electronic patient-reported outcomes (ePROs) for symptom monitoring to enhance the quality of cancer care. Step 1 of the Texas Two-Step Study demonstrated successful implementation of an ePRO system in >200 sites of service of a large community oncology practice. We now report step 2 of this study which evaluates the impact of ePROs on outcomes among patients enrolled in the Centers for Medicare & Medicaid Services' Oncology Care Model (OCM) program. METHODS: This observational study focused on patients with metastatic cancer enrolled in OCM at large community oncology practice located in Texas between July 2020 and December 2020. Patients who completed ≥1 survey via the ePRO tool were included in the study group and were propensity score matched with patients in a control group. Adverse events (AEs; hospitalizations, emergency department visits, deaths) and total cost of care were a priori study outcomes. Mann-Whitney U and chi-square tests compared continuous and categorical variables, respectively, with multivariable logistic regression for adjustment of covariates. RESULTS: Of 831 patients with metastatic cancer, 458 matched patients (229/group) were identified, with 52% male and a mean age of 74 years. Mean total AEs were lower in the study group compared with control (0.98 v 1.41; P = .007), with decreased hospitalizations (20% v 32.5%; P = .002), emergency visits (38.4% v 42.3%; P > .05), and deaths (11.8% v 16.6%; P > .05). Average number of hospitalizations was lower (0.28 v 0.52; P = .003) with reduced mean duration of hospitalizations (1.9 vs 3.2 d; P = .03). The total cost of care was reduced by an average of $1,146 per member per month. CONCLUSION: Symptom monitoring with ePROs improved quality and value of cancer care delivery by reducing hospitalizations, emergency visits, and deaths while lowering cost of care in a large oncology practice.

Differences in Receipt of Immunotherapy Treatment Among Patients With Head and Neck Cancer.

Importance: The US Food and Drug Administration approved immune checkpoint inhibitors (immunotherapy) for select cases of head and neck squamous cell carcinoma (HNSCC) in 2016. However, it is unclear whether there are clinical or sociodemographic differences among patients receiving immunotherapy as part of their care. Given the known disparities in head and neck cancer care, we hypothesized that there are differences in receipt of immunotherapy among patients with HNSCC based on clinical and nonclinical characteristics. Objective: To characterize clinical and nonclinical factors associated with receipt of immunotherapy among older patients with HNSCC. Design, Setting, and Participants: This retrospective cohort study included patients 65 years or older diagnosed with HNSCC (n = 4860) in a community oncology care setting. Electronic health records from Navigating Cancer were assessed from January 1, 2017, to April 30, 2022. Main Outcomes and Measures: Multivariable logistic regression was used to characterize clinical (tumor stage [localized vs advanced] and anatomical subsite [oropharyngeal vs nonoropharyngeal]) and nonclinical (age, smoking history, race and ethnicity, sex, and marital status) factors associated with receipt of immunotherapy. Results: In the study cohort of 4860 patients, 3593 (73.9%) were men; 4230 (87.0%) were White and 630 (13.0%) were of other races. A total of 552 patients (11.4%) had received immunotherapy. After adjusting for covariates, in the final model, White patients with HNSCC had 80% increased odds of receiving immunotherapy (adjusted odds ratio [AOR], 1.80 [95% CI, 1.30-2.48]) compared with patients of other races. There were no statistically significant differences in the odds of receiving immunotherapy based on age, sex, or smoking history. Patients with nonoropharyngeal disease were significantly more likely to receive immunotherapy than those with oropharyngeal cancer (AOR, 1.29 [95% CI, 1.05-1.59]), as were those with advanced compared with local disease (AOR, 2.39 [95% CI, 1.71-3.34]). Conclusions and Relevance: The findings of this cohort study suggest that among older patients with HNSCC, White patients may be more likely to receive immunotherapy as part of their care. Equitable access to immunotherapy and other treatment options will reduce cancer-related health disparities and improve survival of patients with HNSCC.

Sociodemographic Differences in Patient-Reported Pain and Pain Management of Patients With Head and Neck Cancer in a Community Oncology Setting.

PURPOSE: While pain is prevalent among survivors of head and neck cancer (HNC), there is a lack of data on pain management in the community oncology setting. We described sociodemographic correlates and disparities associated with patient-reported pain among patients with HNC. METHODS: We used the 2017-2021 nationwide community oncology data set from Navigating Cancer, which included electronic patient-reported outcomes. We identified a retrospective cohort of patients diagnosed with HNC (N = 25,572), with ≥ 1 patient-reported pain event. We adjusted for demographic (sex, age, smoking history, marital status) and clinical (cancer site) factors associated with pain reporting and pain resolution by new pain prescription on the basis of race (White v non-White patients), using multivariate logistic regression models. RESULTS: Our analytic cohort included 2,331 patients, 90.58% White, 58.62% married, with an average age of 66.47 years. Of these, 857 patients (36.76%) reported ≥ 1 pain event during study period. Mean resolution time (in minutes) for pain incidents was significantly longer for White patients than non-White patients (99.6 ± 3.2 v 74.9 ± 7.2, P < .05). After adjusting for covariates, smoking was associated with a 25% increased odds of reporting pain incidents (adjusted odds ratio [aOR], 1.25; 95% CI, 1.03 to 1.52). There was no statistically significant difference in odds of pain reporting between White versus non-White patients (aOR, 0.97; 95% CI, 0.73 to 1.30). However, White patients were significantly more likely to receive new prescription for pain than non-White patients (aOR, 2.52; 95% CI, 1.09 to 5.86). CONCLUSION: We found racial differences in patient-reported pain management, with White patients significantly more likely to receive new pain prescriptions. As pain management is a mainstay in cancer care, equity in pain management is critical to optimize quality of life for patients with HNC.

Laparoscopic common bile duct exploration after failed endoscopic retrograde cholangio-pancreatography: Our patient series over a period of 10 years.

Aim: Laparoscopic CBD exploration (LCBDE) for Common bile duct (CBD) stones with laparoscopic cholecystectomy (LC) is an alternative to open CBD exploration, in patients with failed endoscopic retrograde cholangio-pancreatography (ERCP). It is being performed at few centres with adequate surgical expertise. Herein, we present our experience of LCBDE with LC over a period of 10 years. Patients and Methods: A retrospective analysis of prospectively recorded data of 121 consecutive patients was performed from February 2010 to November 2019, who underwent LC and LCBDE by choledochotomy in a single surgical unit. These included all patients with failed pre-operative ERCP. Results: Out of 121 patients, LCBDE successfully cleared the CBD in 118, and three patients were converted to open surgery. All these patients underwent choledochotomy for adequate exploration of CBD. T-tube closure of CBD was performed in 103 patients and removed after a mean of 14.6 ± 2.4 days. Primary closure was performed in 15 patients. The mean hospital stay post-procedure was 3.4 ± 0.7 days. Complete ductal clearance was achieved in 115 patients, and residual stone fragments reported in three patients were removed by ERCP. None of the patients experienced biliary peritonitis, biliary fistula, pancreatitis or cholangitis. There was no 30-day mortality and no recurrent stones reported with a mean follow-up of 12.4 ± 3.9 months. Conclusion: With adequate surgical expertise, LCBDE is a feasible alternative to open surgery for CBD stones after failed ERCP with early recovery and low morbidity.

Exosomal markers (CD63 and CD9) expression and their prognostic significance using immunohistochemistry in patients with pancreatic ductal adenocarcinoma.

BACKGROUND: Exosomes are important mediators of intercellular communications and play pivotal roles in cancer progression, metastasis and chemoresistance. CD63 and CD9 are widely accepted exosomal markers. In patients with pancreatic ductal adenocarcinoma (PDAC), positive correlation between CD9 expression and overall survival (OS) was reported. CD63 expression was conserved in all patients with no reported prognostic significance. This study explored the prognostic significance of CD63 and CD9 expression using immunohistochemistry (IHC) in patients with PDAC of mixed racial background. METHODS: Between 2012 and 2016, 49 patients with PDAC had available tissues for CD63 and CD9 staining using IHC. Two pathologists independently scored the CD63 and CD9 expression. Staining intensity was graded from 1-3 and staining percentage was estimated in 10% increments. Mean Quick-score (Q-score) (Intensity X Percentage of staining) was calculated. RESULTS: The mean Q-score for CD63 and CD9 are higher in primary tumor from the pancreas compared to pancreatic tumor from metastatic sites (185 vs. 102, P=0.0002) and (48 vs. 20, P=0.0418) respectively. We fitted Cox proportion hazard regression models to investigate the impact of the covariates CD63 and CD9 on progression free survival (PFS) and OS. CD63 has significant impact on PFS (P=0.0135) and OS (P=0.003). The higher the CD63 Q-score, the longer the PFS and OS. CD9 doesn't have significant impact on PFS (P=0.5734) or OS (P=0.2682). The mean CD63 and CD9 Q-scores are slightly higher in African American (AA) compared to Caucasians (157 vs. 149, P=0.76) and (45 vs. 29, P=0.43) respectively. CONCLUSIONS: CD63 and CD9 expression is higher in primary tumor from the pancreas compared to pancreatic tumor from metastatic sites. There is correlation between CD63 expression (but not CD9 in this cohort) and PFS and OS. To our knowledge, this is the first study to show prognostic significance of CD63 expression in patients with PDAC using IHC. A trend of higher expression of CD63 and CD9 among AA compared to Caucasians was also noticed.

Hydroxytyrosol Induces Apoptosis and Cell Cycle Arrest and Suppresses Multiple Oncogenic Signaling Pathways in Prostate Cancer Cells.

SCOPE: Hydroxytyrosol (HT), a polyphenol from olives, is a potential anticancer agent. This study was designed to evaluate the anticancer activity of HT against prostate cancer cells, and the mechanism thereof. METHODS AND RESULTS: Treatment of LNCaP and C4-2 prostate cancer cells with HT resulted in a dose-dependent inhibition of proliferation. This was in contrast to HT's ineffectiveness against normal prostate epithelial cells RWPE1 and PWLE2, suggesting cancer-cell-specific effect. HT induced G1/S cell cycle arrest, with inhibition of cyclins D1/E and cdk2/4 and induction of inhibitory p21/p27. HT also induced apoptosis, as confirmed by flow cytometry, caspase activation, PARP cleavage, and BAX/Bcl-2 ratio. It inhibited the phosphorylation of Akt/STAT3, and induced cytoplasmic retention of NF-κB, which may explain its observed effects. Finally, HT inhibited androgen receptor (AR) expression and the secretion of AR-responsive prostate-specific antigen. CONCLUSION: Castration-resistant prostate cancers retain AR signaling and are often marked by activated Akt, NF-κB, and STAT3 signaling. Our results establish a pleiotropic activity of HT against these oncogenic signaling pathways. Combined with its nontoxic effects against normal cells, our results support further testing of HT for prostate cancer therapy.

Exosomal Markers (CD63 and CD9) Expression Pattern Using Immunohistochemistry in Resected Malignant and Nonmalignant Pancreatic Specimens.

OBJECTIVES: Exosomes are important mediators in intercellular communications and play a role in cancer progression and metastasis. Exosomal membranes are enriched in endosome-specific tetraspanins (CD9 and CD63). Here, we explored the expression of CD63 and CD9 utilizing immunohistochemistry in malignant and nonmalignant cells in 29 resected pancreatic specimens (RPSs) of mixed racial background. METHODS: The pathologic tissues (PTs) and adjacent normal tissues (ANTs) in each RPS were stained for CD63 and CD9. Two pathologists independently scored the expression of CD63 and CD9. Staining intensity was graded from 1 to 3. Staining percentage was estimated in 10% increments. An average Quick score (Q score) (intensity × percentage of staining) was calculated. Unpaired t test was used for statistical analysis. RESULTS: The mean multiplicative Q score for CD63 and CD9 expression is higher in PTs (209 and 72) compared with ANTs (154 and 24) (P = 0.0041, P = 0.0018), respectively. The Mean Q score for CD63 and CD9 expression is higher in the malignant PTs (231 and 85) compared with ANTs (129 and 25) (P < 0.0001 and P < 0.0124). CONCLUSIONS: Exosomal markers (CD63 and CD9) expression assessment using immunohistochemistry is feasible in RPS. The expression of CD63 and CD9 is higher in PTs and malignant PTs compared with their ANTs.

Molecular Drivers of Pancreatic Cancer Pathogenesis: Looking Inward to Move Forward.

Pancreatic cancer (PC) continues to rank among the most lethal cancers. The consistent increase in incidence and mortality has made it the seventh leading cause of cancer-associated deaths globally and the third in the United States. The biggest challenge in combating PC is our insufficient understanding of the molecular mechanism(s) underlying its complex biology. Studies during the last several years have helped identify several putative factors and events, both genetic and epigenetic, as well as some deregulated signaling pathways, with implications in PC onset and progression. In this review article, we make an effort to summarize our current understanding of molecular and cellular events involved in the pathogenesis of pancreatic malignancy. Specifically, we provide up-to-date information on the genetic and epigenetic changes that occur during the initiation and progression of PC and their functional involvement in the pathogenic processes. We also discuss the impact of the tumor microenvironment on the molecular landscape of PC and its role in aggressive disease progression. It is envisioned that a better understanding of these molecular factors and the mechanisms of their actions can help unravel novel diagnostic and prognostic biomarkers and can also be exploited for future targeted therapies.

Resistin potentiates chemoresistance and stemness of breast cancer cells: Implications for racially disparate therapeutic outcomes.

Breast cancer (BC) continues to be the most frequently diagnosed cancer in American women, which disproportionately affects women of African-American (AA) descent. Previously, we reported greater serum levels of resistin in AA BC patients relative to Caucasian-American (CA) patients, and established its role in growth and aggressiveness of breast tumor cells. Here we have investigated the role of resistin in BC-chemoresistance. MDA-MB-231 and MDA-MB-468 BC cells of CA and AA origin, respectively, were incubated with resistin prior to doxorubicin treatment. Our data suggest that resistin conferred chemoresistance to both BC cell lines; however, the effect on AA cells was more profound. Furthermore, the resistin-induced doxorubicin-resistance was shown to occur due to suppression of apoptosis. Resistin treatment also affected the stemness of BC cells, as suggested by reduced cell surface expression of CD24, induced expression of CD44 and ALDH1, and increased capability of cells to form mammospheres. Mechanistic studies revealed that resistin-induced chemoresistance, apoptosis and stemness of BC cells were mediated through STAT3 activation. Taken together, our findings provide novel insight into the role of resistin in BC biology, and strengthen its role in racially disparate clinical outcomes.

Exosomes confer chemoresistance to pancreatic cancer cells by promoting ROS detoxification and miR-155-mediated suppression of key gemcitabine-metabolising enzyme, DCK.

BACKGROUND: Chemoresistance is a significant clinical problem in pancreatic cancer (PC) and underlying molecular mechanisms still remain to be completely understood. Here we report a novel exosome-mediated mechanism of drug-induced acquired chemoresistance in PC cells. METHODS: Differential ultracentrifugation was performed to isolate extracellular vesicles (EVs) based on their size from vehicle- or gemcitabine-treated PC cells. Extracellular vesicles size and subtypes were determined by dynamic light scattering and marker profiling, respectively. Gene expression was examined by qRT-PCR and/or immunoblot analyses, and direct targeting of DCK by miR-155 was confirmed by dual-luciferase 3'-UTR reporter assay. Flow cytometry was performed to examine the apoptosis indices and reactive oxygen species (ROS) levels in PC cells using specific dyes. Cell viability was determined using the WST-1 assay. RESULTS: Conditioned media (CM) from gemcitabine-treated PC cells (Gem-CM) provided significant chemoprotection to subsequent gemcitabine toxicity and most of the chemoresistance conferred by Gem-CM resulted from its EVs fraction. Sub-fractionation grouped EVs into distinct subtypes based on size distribution and marker profiles, and exosome (Gem-Exo) was the only sub-fraction that imparted chemoresistance. Gene expression analyses demonstrated upregulation of SOD2 and CAT (ROS-detoxifying genes), and downregulation of DCK (gemcitabine-metabolising gene) in Gem-Exo-treated cells. SOD/CAT upregulation resulted, at least in part, from exosome-mediated transfer of their transcripts and they suppressed basal and gemcitabine-induced ROS production, and partly promoted chemoresistance. DCK downregulation occurred through exosome-delivered miR-155 and either the functional suppression of miR-155 or restoration of DCK led to marked abrogation of Gem-Exo-mediated chemoresistance. CONCLUSIONS: Together, these findings establish a novel role of exosomes in mediating the acquired chemoresistance of PC.

Biological basis of cancer health disparities: resources and challenges for research.

Last few decades have witnessed remarkable progress in our understanding of cancer initiation and progression leading to refinement of prevention and treatment approaches. Although these advances have improved the survival of cancer patients in general, certain racial/ethnic groups have benefited only partially. Footprints of cancer-associated racial disparities are very much evident in cancers of the prostate, breast, cervical, colorectal, endometrium, liver and lung. These health inequalities are mostly attributed to socioeconomic differences among races, but there is a growing realization that these may actually be due to inherent biological differences as well. Indeed, significant data now exist to support the biological basis of racial disparities in cancer, warranting basic research investigations, using appropriate tools and model systems. In this article, we have aimed to succinctly review the literature supporting the biological bases of racial disparities in cancer, along with available resources, databases and model systems that will be of interest to researchers. Moreover, we have highlighted the specific areas that need attention in terms of development of resources and/or tools, and discuss the opportunities and challenges in basic biological research in cancer health disparities.

Racial disparities in prostate cancer: a molecular perspective.

Prostate cancer incidence and mortality rates are remarkably higher in African-American men as compared to their European-Americans counterparts. Despite these recognitions, precise causes underlying such prevalent racial disparities remain poorly understood. Although socioeconomic factors could account for such differences up to a certain extent, it is now being increasingly realized that such disparity has a molecular basis. Indeed, several differences, including genetic polymorphism, gene mutations, epigenetic modifications, miRNAs alterations, etc., have been reported in malignant prostate tissues from patients of diverse racial backgrounds. Here, we attempt to provide a molecular perspective on prostate cancer racial disparities by gathering available information on these associated factors and discussing their potential significance in disproportionate incidence and clinical outcomes.

Glucose Metabolism Reprogrammed by Overexpression of IKKε Promotes Pancreatic Tumor Growth.

Aberrant expression of the kinase IKKε in pancreatic ductal adenocarcinoma (PDAC) has been associated with poor prognosis. In this study, we define a pathobiologic function for IKKε in reprogramming glucose metabolism and driving progression in PDAC. Silencing IKKε in PDAC cells, which overexpressed it endogenously, was sufficient to reduce malignant cell growth, clonogenic potential, glucose consumption, lactate secretion, and expression of genes involved in glucose metabolism, without impacting the basal oxygen consumption rate. IKKε silencing also attenuated c-Myc in a manner associated with diminished signaling through an AKT/GSK3ß/c-MYC phosphorylation cascade that promoted MYC nuclear accumulation. In an orthotopic mouse model, IKKε-silenced PDAC exhibited a relative reduction in glucose uptake, tumorigenicity, and metastasis. Overall, our findings offer a preclinical mechanistic rationale to target IKKε to improve the therapeutic management of PDAC in patients. Cancer Res; 76(24); 7254-64. ©2016 AACR.

Honokiol suppresses pancreatic tumor growth, metastasis and desmoplasia by interfering with tumor-stromal cross-talk.

The poor clinical outcome of pancreatic cancer (PC) is largely attributed to its aggressive nature and refractoriness to currently available therapeutic modalities. We previously reported antitumor efficacy of honokiol (HNK), a phytochemical isolated from various parts of Magnolia plant, against PC cells in short-term in vitro growth assays. Here, we report that HNK reduces plating efficiency and anchorage-independent growth of PC cells and suppresses their migration and invasiveness. Furthermore, significant inhibition of pancreatic tumor growth by HNK is observed in orthotopic mouse model along with complete-blockage of distant metastases. Histological examination suggests reduced desmoplasia in tumors from HNK-treated mice, later confirmed by immunohistochemical analyses of myofibroblast and extracellular matrix marker proteins (α-SMA and collagen I, respectively). At the molecular level, HNK treatment leads to decreased expression of sonic hedgehog (SHH) and CXCR4, two established mediators of bidirectional tumor-stromal cross-talk, both in vitro and in vivo . We also show that the conditioned media (CM) from HNK-treated PC cells have little growth-inducing effect on pancreatic stellate cells (PSCs) that could be regained by the addition of exogenous recombinant SHH. Moreover, pretreatment of CM of vehicle-treated PC cells with SHH-neutralizing antibody abolishes their growth-inducing potential on PSCs. Likewise, HNK-treated PC cells respond poorly to CM from PSCs due to decreased CXCR4 expression. Lastly, we show that the transfection of PC cells with constitutively active IKKß mutant reverses the suppressive effect of HNK on nuclear factor-kappaB activation and partially restores CXCR4 and SHH expression. Taken together, these findings suggest that HNK interferes with tumor-stromal cross-talk via downregulation of CXCR4 and SHH and decreases pancreatic tumor growth and metastasis.

Deep sequencing and in silico analyses identify MYB-regulated gene networks and signaling pathways in pancreatic cancer.

We have recently demonstrated that the transcription factor MYB can modulate several cancer-associated phenotypes in pancreatic cancer. In order to understand the molecular basis of these MYB-associated changes, we conducted deep-sequencing of transcriptome of MYB-overexpressing and -silenced pancreatic cancer cells, followed by in silico pathway analysis. We identified significant modulation of 774 genes upon MYB-silencing (p < 0.05) that were assigned to 25 gene networks by in silico analysis. Further analyses placed genes in our RNA sequencing-generated dataset to several canonical signalling pathways, such as cell-cycle control, DNA-damage and -repair responses, p53 and HIF1α. Importantly, we observed downregulation of the pancreatic adenocarcinoma signaling pathway in MYB-silenced pancreatic cancer cells exhibiting suppression of EGFR and NF-κB. Decreased expression of EGFR and RELA was validated by both qPCR and immunoblotting and they were both shown to be under direct transcriptional control of MYB. These observations were further confirmed in a converse approach wherein MYB was overexpressed ectopically in a MYB-null pancreatic cancer cell line. Our findings thus suggest that MYB potentially regulates growth and genomic stability of pancreatic cancer cells via targeting complex gene networks and signaling pathways. Further in-depth functional studies are warranted to fully understand MYB signaling in pancreatic cancer.

MYB Promotes Desmoplasia in Pancreatic Cancer through Direct Transcriptional Up-regulation and Cooperative Action of Sonic Hedgehog and Adrenomedullin.

Extensive desmoplasia is a prominent pathological characteristic of pancreatic cancer (PC) that not only impacts tumor development, but therapeutic outcome as well. Recently, we demonstrated a novel role of MYB, an oncogenic transcription factor, in PC growth and metastasis. Here we studied its effect on pancreatic tumor histopathology and associated molecular and biological mechanisms. Tumor-xenografts derived from orthotopic-inoculation of MYB-overexpressing PC cells exhibited far-greater desmoplasia in histological analyses compared with those derived from MYB-silenced PC cells. These findings were further confirmed by immunostaining of tumor-xenograft sections with collagen-I, fibronectin (major extracellular-matrix proteins), and α-SMA (well-characterized marker of myofibroblasts or activated pancreatic stellate cells (PSCs)). Likewise, MYB-overexpressing PC cells provided significantly greater growth benefit to PSCs in a co-culture system as compared with the MYB-silenced cells. Interrogation of deep-sequencing data from MYB-overexpressing versus -silenced PC cells identified Sonic-hedgehog (SHH) and Adrenomedullin (ADM) as two differentially-expressed genes among others, which encode for secretory ligands involved in tumor-stromal cross-talk. In-silico analyses predicted putative MYB-binding sites in SHH and ADM promoters, which was later confirmed by chromatin-immunoprecipitation. A cooperative role of SHH and ADM in growth promotion of PSCs was confirmed in co-culture by using their specific-inhibitors and exogenous recombinant-proteins. Importantly, while SHH acted exclusively in a paracrine fashion on PSCs and influenced the growth of PC cells only indirectly, ADM could directly impact the growth of both PC cells and PSCs. In summary, we identified MYB as novel regulator of pancreatic tumor desmoplasia, which is suggestive of its diverse roles in PC pathobiology.

p-21 activated kinase 4 (PAK4) maintains stem cell-like phenotypes in pancreatic cancer cells through activation of STAT3 signaling.

Pancreatic cancer (PC) remains a highly lethal malignancy due to its unusual chemoresistance and high aggressiveness. A subpopulation of pancreatic tumor cells, known as cancer stem cells (CSCs), is considered responsible not only for tumor-maintenance, but also for its widespread metastasis and therapeutic failure. Here we investigated the role of p-21 activated kinase 4 (PAK4) in driving PC stemness properties. Our data demonstrate that triple-positive (CD24(+)/CD44(+)/EpCAM(+)) subpopulation of pancreatic CSCs exhibits greater level of PAK4 as compared to triple-negative (CD24(-)/CD44(-)/EpCAM(-)) cells. Moreover, PAK4 silencing in PC cells leads to diminished fraction of CD24, CD44, and EpCAM positive cells. Furthermore, we show that PAK4-silenced PC cells exhibit decreased sphere-forming ability and increased chemosensitivity to gemcitabine toxicity. PAK4 expression is also associated with enhanced levels of stemness-associated transcription factors (Oct4/Nanog/Sox2 and KLF4). Furthermore, our data show decreased nuclear accumulation and transcriptional activity of STAT3 in PAK4-silenced PC cells and restitution of its activity leads to restoration of stem cell phenotypes. Together, our findings deliver first experimental evidence for the involvement of PAK4 in PC stemness and support its clinical utility as a novel therapeutic target in PC.

MYB is a novel regulator of pancreatic tumour growth and metastasis.

BACKGROUND: MYB encodes for a transcription factor regulating the expression of a wide array of genes involved in cellular functions. It is reported to be amplified in a sub-set of pancreatic cancer (PC) cases; however, its pathobiological association has remained unclear thus far. METHODS: Expression of MYB and other cellular proteins was analysed by immunoblot or qRT-PCR analyses. MYB was stably overexpressed in non-expressing (BxPC3) and silenced in highly expressing (MiaPaCa and Panc1) PC cells. Effect on growth was analysed by automated cell counting at 24-h interval. Cell-cycle progression and apoptotic indices of PC cells with altered MYB expression were measured through flow cytometry upon staining with respective biomarkers. Cell motility/invasion was examined in a Boyden's chamber assay using non-coated or Matrigel-coated membranes. Effect on tumorigenicity and metastatic potential was examined by non-invasive imaging and through end-point measurements of luciferase-tagged MYB-altered PC implanted in the pancreas of nude mice. RESULTS: MYB was aberrantly expressed in all malignant cases of pancreas, whereas remained undetectable in normal pancreas. All the tested established PC cell lines except BxPC3 also exhibited MYB expression. Forced expression of MYB in BxPC3 cells promoted their growth, cell-cycle progression, survival and malignant behaviour, whereas its silencing in MiaPaCa and Panc1 cells produced converse effects. More importantly, ectopic MYB expression was sufficient to confer tumorigenic and metastatic capabilities to non-tumorigenic BxPC3 cells, while its silencing resulted in significant loss of the same in MYB-overexpressing cells as demonstrated in orthotopic mouse model. We also identified several MYB-regulated genes in PC cells that might potentially mediate its effect on tumour growth and metastasis. CONCLUSIONS: MYB is aberrantly overexpressed in PC cells and acts as a key determinant of pancreatic tumour growth and metastasis.

In vivo efficacy and toxicity evaluation of polycaprolactone nanoparticles and aluminum based admixture formulation as vaccine delivery system.

Delivery of antigen through admixture formulation containing poly caprolactone (PCL) and aluminum phosphate was studied as a promising strategy to generate antigen specific immune response. The present study demonstrates the synergistic effect of admixture formulation of PCL with reduced aluminum (PCL-Al 0.2 mg-TT and PCL-PEG-Al 0.2 mg-TT) as a potential adjuvant system using tetanus toxoid (TT) as a model antigen. On evaluation of the magnitude of efficacy for the proposed formulation by ELISA as well as challenge method, persistent and strong antibody response was obtained throughout the 180 day study period on storage at 5 ± 3 °C. In comparison to the aluminum phosphate based conventional tetanus vaccine, higher levels of IFN-γ and IL-4 were obtained with PCL-Al 0.2 mg-TT and PCL-PEG-Al 0.2 mg-TT, indicating the presence of cell mediated as well as humoral immune responses. Histopathology and serum biochemistry profile in mice further indicated the suitability of the proposed formulation. Percent adsorption/encapsulation of the antigen also increased to nearly 95% in the admixture formulation compared to 55% adsorption in the conventional tetanus vaccine. The present study established a useful baseline for designing biocompatible and effective delivery system for toxoid vaccines through judicious use of PCL based biodegradable nanoparticles in combination with aluminum phosphate.

Development and Characterization of a Novel in vitro Progression Model for UVB-Induced Skin Carcinogenesis.

Epidemiological studies suggest ultraviolet B (UVB) component (290-320 nm) of sun light is the most prevalent etiologic factor for skin carcinogenesis--a disease accounting for more than two million new cases each year in the USA alone. Development of UVB-induced skin carcinoma is a multistep and complex process. The molecular events that occur during UVB-induced skin carcinogenesis are poorly understood largely due to the lack of an appropriate cellular model system. Therefore, to make a progress in this area, we have developed an in vitro model for UVB-induced skin cancer using immortalized human epidermal keratinocyte (HaCaT) cells through repetitive exposure to UVB radiation. We demonstrate that UVB-transformed HaCaT cells gain enhanced proliferation rate, apoptosis-resistance, and colony- and sphere-forming abilities in a progressive manner. Moreover, these cells exhibit increased aggressiveness with enhanced migration and invasive potential and mesenchymal phenotypes. Furthermore, these derived cells are able to form aggressive squamous cell carcinoma upon inoculation into the nude mice, while parental HaCaT cells remain non-tumorigenic. Together, these novel, UVB-transformed progression model cell lines can be very helpful in gaining valuable mechanistic insight into UVB-induced skin carcinogenesis, identification of novel molecular targets of diagnostic and therapeutic significance, and in vitro screening for novel preventive and therapeutic agents.