PM21-particle stimulation augmented with cytokines enhances NK cell expansion and confers memory-like characteristics with enhanced survival

NK cell therapeutics have gained significant attention as a potential cancer treatment. Towards therapeutic use, NK cells need to be activated and expanded to attain high potency and large quantities for an effective dosage. This is typically done by ex vivo stimulation with cytokines to enhance functionality or expansion for 10-14 days to increase both their activity and quantity. Attaining a robust methodology to produce large doses of potent NK cells for an off-the-shelf product is highly desirable. Notably, past reports have shown that stimulating NK cells with IL-12, IL-15, and IL-18 endows them with memory-like properties, better anti-tumor activity, and persistence. While this approach produces NK cells with clinically favorable characteristics supported by encouraging early results for the treatment of hematological malignancies, its limited scalability, variability in initial doses, and the necessity for patient-specific production hinder its broader application. In this study, stimulation of NK cells with PM21-particles derived from K562-41BBL-mbIL21 cells was combined with memory-like induction using cytokines IL-12, IL-15, and IL-18 to produce NK cells with enhanced anti-tumor function. The use of cytokines combined with PM21-particles (cytokine and particle, CAP) significantly enhanced NK cell expansion, achieving a remarkable 8,200-fold in 14 days. Mechanistically, this significant improvement over expansion with PM21-particles alone was due to the upregulation of receptors for key stimulating ligands (4-1BBL and IL-2), resulting in a synergy that drives substantial NK cell growth, showcasing the potential for more effective therapeutic applications. The therapeutic potential of CAP-NK cells was demonstrated by the enhanced metabolic fitness, persistence, and anti-tumor function both in vitro and in vivo. Finally, CAP-NK cells were amenable to current technologies used in developing therapeutic NK cell products, including CRISPR/Cas9-based techniques to generate a triple-gene knockout or a gene knock-in. Taken together, these data demonstrate that the addition of cytokines enhanced the already effective method of ex vivo generation of therapeutic NK cells with PM21-particles, yielding a superior NK cell product for manufacturing efficiency and potential therapeutic applications.

Knockout of the inhibitory receptor TIGIT enhances the antitumor response of ex vivo expanded NK cells and prevents fratricide with therapeutic Fc-active TIGIT antibodies

BACKGROUND

Inhibitory receptor T-cell Immunoreceptor with Ig and ITIM domains (TIGIT) expressed by Natural Killer (NK) and T cells regulates cancer immunity and has been touted as the next frontier in the development of cancer immunotherapeutics. Although early results of anti-TIGIT and its combinations with antiprogrammed death-ligand 1 were highly exciting, results from an interim analysis of phase III trials are disappointing. With mixed results, there is a need to understand the effects of therapeutic anti-TIGIT on the TIGIT+ immune cells to support its clinical use. Most of the TIGIT antibodies in development have an Fc-active domain, which binds to Fc receptors on effector cells. In mouse models, Fc-active anti-TIGIT induced superior immunity, while Fc receptor engagement was required for its efficacy. NK-cell depletion compromised the antitumor immunity of anti-TIGIT indicating the essential role of NK cells in the efficacy of anti-TIGIT. Since NK cells express TIGIT and Fc-receptor CD16, Fc-active anti-TIGIT may deplete NK cells via fratricide, which has not been studied.

METHODS

CRISPR-Cas9-based TIGIT knockout (KO) was performed in expanded NK cells. Phenotypic and transcriptomic properties of TIGIT KO and wild-type (WT) NK cells were compared with flow cytometry, CyTOF, and RNA sequencing. The effect of TIGIT KO on NK-cell cytotoxicity was determined by calcein-AM release and live cell imaging-based cytotoxicity assays. The metabolic properties of TIGIT KO and WT NK cells were compared with a Seahorse analyzer. The effect of the Fc-component of anti-TIGIT on NK-cell fratricide was determined by co-culturing WT and TIGIT KO NK cells with Fc-active and Fc-inactive anti-TIGIT.

RESULTS

TIGIT KO increased the cytotoxicity of NK cells against multiple cancer cell lines including spheroids. TIGIT KO NK cells upregulated mTOR complex 1 (mTORC1) signaling and had better metabolic fitness with an increased basal glycolytic rate when co-cultured with cancer cells compared with WT NK cells. Importantly, TIGIT KO prevented NK-cell fratricide when combined with Fc-active anti-TIGIT.

CONCLUSIONS

TIGIT KO in ex vivo expanded NK cells increased their cytotoxicity and metabolic fitness and prevented NK-cell fratricide when combined with Fc-active anti-TIGIT antibodies. These fratricide-resistant TIGIT KO NK cells have therapeutic potential alone or in combination with Fc-active anti-TIGIT antibodies to enhance their efficacy.

The Impact of Berberine Loaded Selenium Nanoparticles on K. pneumoniae and Candida albicans Antibiotics Resistance Isolates

This study aimed to investigate the antibacterial and antifungal activities of selenium nanoparticles (SeNPs) and berberine (BBR) despite antibiotic resistance against Klebsiella pneumoniae and Candida albicans. Cells of K. pneumoniae and C. albicans were treated with solutions of different concentrations of each bare SeNPs, BBR, and BBR-loaded SeNPs (BLS) using the disk diffusion method. The results indicated that the activities of SeNPs, BBR, and BLS were statistically significant (P<0.05) when the concentration of all agents increased. Moreover, it was found that BLS had a statistically significant effect against K. pneumoniae and C. albicans, compared to SeNPs and BBR alone (P<0.05). The largest zones of inhibition of SeNPs were 14 and 16 mm toward K. pneumoniae and C. albicans, respectively, at the concentration of 20 Mml, compared to the concentrations of 10 and 15 Mml. Furthermore, BBR showed a maximum zone of inhibition at the concentration of 1,200 mg (15 mm for K. pneumoniae and 18 mm for C. albicans) and it was statistically significant in comparison with other concentrations of 400 and 800 mg. In addition, the BLS underwent a statistically significant increase (P<0.05) when the concentration increased and it registered a large zone of inhibition of 22 and 25 mm against K. pneumoniae and C. albicans, respectively, at 20 Mml of SeNPs: 1,200 mg BBR, compared to 10 Mml of SeNPs: 400 mg BBR and 15 Mml of SeNPs: 800 mg BBR. Based on the results of the current study, there was a statistically synergistic effect of BBR-loaded SeNPs, compared to that of BBR and Se nanoparticles, only in the case of both K. pneumoniae and C. albicans. This study is promising as a blueprint for the enhancement of weak antimicrobial agents and their return to their previous role as antibiotics.

TIGIT Expression on Activated NK Cells Correlates with Greater Anti-Tumor Activity but Promotes Functional Decline upon Lung Cancer Exposure: Implications for Adoptive Cell Therapy and TIGIT-Targeted Therapies

Treatments targeting TIGIT have gained a lot of attention due to strong preclinical and early clinical results, particularly with anti-PD-(L)1 therapeutics. However, this combination has failed to meet progression-free survival endpoints in phase III trials. Most of our understanding of TIGIT comes from studies of T cell function. Yet, this inhibitory receptor is often upregulated to the same, or higher, extent on NK cells in cancers. Studies in murine models have demonstrated that TIGIT inhibits NK cells and promotes exhaustion, with its effects on tumor control also being dependent on NK cells. However, there are limited studies assessing the role of TIGIT on the function of human NK cells (hNK), particularly in lung cancer. Most studies used NK cell lines or tested TIGIT blockade to reactivate exhausted cells obtained from cancer patients. For therapeutic advancement, a better understanding of TIGIT in the context of activated hNK cells is crucial, which is different than exhausted NK cells, and critical in the context of adoptive NK cell therapeutics that may be combined with TIGIT blockade. In this study, the effect of TIGIT blockade on the anti-tumor activities of human ex vivo-expanded NK cells was evaluated in vitro in the context of lung cancer. TIGIT expression was higher on activated and/or expanded NK cells compared to resting NK cells. More TIGIT⁺ NK cells expressed major activating receptors and exerted anti-tumor response as compared to TIGIT^- cells, indicating that NK cells with greater anti-tumor function express more TIGIT. However, long-term TIGIT engagement upon exposure to PVR⁺ tumors downregulated the cytotoxic function of expanded NK cells while the inclusion of TIGIT blockade increased cytotoxicity, restored the effector functions against PVR-positive targets, and upregulated immune inflammation-related gene sets. These combined results indicate that TIGIT blockade can preserve the activation state of NK cells during exposure to PVR⁺ tumors. These results support the notion that a functional NK cell compartment is critical for anti-tumor response and anti-TIGIT/adoptive NK cell combinations have the potential to improve outcomes.

Assessing the Effectiveness of Clinical Skills Laboratory and Traditional Lecture in Teaching Basic Life Support and Performance Evaluation According to Different Domains of Revised Bloom's Taxonomy

Sudden cardiac arrest out-side hospital is serious global concern. If non-medical people are taught to initiate the basic life support (BLS) training with cardiopulmonary resuscitation (CPR) then the mortality could be reduced significantly. This was a non-randomized controlled study to evaluate clinical skills laboratory (CSL) as teaching tool for basic life support (BLS) training in comparison to traditional lecture. Sample size was 68 and performed in Sylhet Women's Medical College from July 2022 to September 2022. All the participants were third year nursing students. They were enrolled in to two groups. Group-A were taught BLS by clinical skills laboratory (CSL) and Group-B were taught by traditional lecture (TL). At the end of the teaching all of them were tested by a vetted multiple choice question (MCQ) set. The questions were set according the 5 levels of revised Blood's taxonomy. Mean score of Group-A (CSL) were higher the TL group (p=0.0003). Among the revised Bloom's taxonomy understand, apply and evaluate domains were significantly better taught (p<0.05) by CSL. The sensitivity of CSL was 0.559 in comparison to TL for BLS training. In the modern medical education teaching and assessment should be focused on the higher levels of learning taxonomy. Introducing CSL in medical education could boost up the psychomotor and cognition both in the medical education.

Myers-Briggs Type Indicator Personality Types of Female Intern Doctors and Their Specialty Preference

The Myers-Briggs Type Indicator (MBTI) personality types were established in 1940s. Career planning of doctors were found related to the MBTI personality. There are 16 subtypes of MBTI based on 4 dichotomies. Relationship between MBTI and career choice has been changed gradually in last few decades. Extroverted doctors are supposed to select surgery and introverted are prone to choose medicine according to MBTI study. This was a cross-sectional study on the female interns of Sylhet Women's Medical College Hospital, Bangladesh from September 2021 to November 2021, to evaluate their MBTI personality type and the career planning of these individual subtypes. Commonest subtypes of participants ISTP (Introverted, Sensing, Thinking, Perceiving) (14.13%) and ESTP (Extraverted, Observant, Thinking and Prospecting) (14.13%). Other common MBTI personality subtypes were ISTJ (Introversion, Sensing, Thinking and Judgment) (9.78%), ISFP (Introverted, Sensing, Feeling, Perceiving) (8.69%), ESFJ (Extraverted, Sensing, Feeling and Judging) (6.52%), ENTP (Extraverted, Intuitive, Thinking and Perceiving) (5.43%), INFJ (Introverted, Intuitive, Feeling and Judging) (5.43%), INTJ (Introverted, Intuitive, Thinking and Judging) (5.43%) and ISFJ (Introverted, Sensing, Feeling and Judging) (5.43%). Introverted (57.7%) participants were more than extroverted (42.3%) participants. Percentage of general surgery and OBG were higher in the extroverted group and the percentage of medicine was more in the introverted group but the differences were not statistically significant (p>0.05). The career planning of ENFJ, ENFP, ESTP and ISTJ subtypes of participants of this study had similarity of those of MBTI database.

Kinetic, imaging based assay to measure NK cell cytotoxicity against adherent cells

Natural Killer cells (NK cells) are a key component of the innate immune system and are key effectors of immunosurveillance. NK cells not only have the inherent ability to directly kill malignant, compromised, or virally infected cells, but also recruit and coordinate responses by other immune cells to prime the adaptive immune response. Given this potent anti-tumor response and good safety profile, adoptive NK cell therapy is an emerging cancer treatment modality. Direct killing of tumor cells is major mode of action for NK cell anti-tumor activity and measuring changes in NK cell cytotoxic response in vitro is a critical step in pre-clinical evaluation of novel NK cellular products. Here, we provide a detailed protocol for a live-cell imaging assay for testing NK cell cytotoxicity against a broad range of adherent and 3D in vitro tumor models. Compared to other methods for measuring in vitro cytotoxicity, this method offers real-time dynamic tracking of and provides a multiparameter readout for more robust understanding of NK cell tumor killing.

690 TIGIT blockade improves anti-tumor activity of ex vivo expanded NK cells

Background

Natural killer (NK) cells are innate immune cells that directly kill and coordinate responses against cancer prompting interest in using ex vivo expanded NK cells as an adoptive cell therapy for treatment of cancer. NK cells express a set of activating and inhibitory receptors that regulate their activity. Inhibitory receptor TIGIT (T cell Immunoreceptor with Ig and ITIM domain) is upregulated on intratumoral NK cells in some cancers, inhibits NK cell activity and promotes NK cell exhaustion. In this study, the effect of TIGIT blockade on the anti-tumor activities of ex vivo expanded NK cells was evaluated.

Methods

NK cells were activated overnight with cytokines or ex vivo expanded with PM21-particles. Their TIGIT expression was determined with qRT-PCR and flow cytometry. Cytotoxicity was assessed by kinetic, imaging-based assay (Incucyte S3) against A549 and NCI-H1299 cells cultured in 3D. Cytotoxicity was calculated based on untreated controls at different time-points. Results from multiple donors were normalized to cytotoxicity of NK cells with isotype for individual donors and was compared to the cytotoxicity of NK cells with anti-TIGIT. Unpaired t test was used to determine statistical significance. K562 cells stably expressing Polio Virus Receptor (PVR), were used to restimulate A549 spheroid-exposed NK cells to measure IFNγ, TNFα and degranulation. Furthermore, phenotypic changes of NK cells upon TIGIT blockade were examined by analyzing a set of activating and inhibitory receptors by flow cytometry.

Results

The effect of NK cell expansion/activation on TIGIT expression was assessed. TIGIT was upregulated on expanded and cytokine-activated NK cells both on mRNA and protein level. The effect of TIGIT blockade on NK cell cytotoxicity was examined by co-culturing PM21-NK cells with cancer cells in the presence of anti-TIGIT antibodies or respective isotypes. TIGIT blockade significantly increased cytotoxicity of PM21-NK cells against A549 (1.3 fold, P < 0.0001) and NCI-H1299 (1.3 fold, P = 0.0003) spheroids after 48 h. To access exhaustion, NK cells exposed to A549 spheroids for 7 days were restimulated with PVR+ K562 cells. TIGIT blockade prevented NK cell exhaustion resulting in increased expression of IFNγ, TNFα and surface CD107a on restimulated NK cells. TIGIT blockade did not result in changes to the surface phenotype of NK cells.

Conclusions

TIGIT was highly expressed on expanded and cytokine-activated NK cells. TIGIT blockade improved anti-tumor activities of PM21-NK cells. Thus, PM21-NK cells and TIGIT antibodies have translational potential as a combination therapy to improve anti-tumor response.

688 Knockout of the inhibitory receptor TIGIT enhances anti-tumor response of ex vivo expanded NK cells

Background

Natural Killer (NK) cells are an important immune cell population crucial for the success of many immunotherapies due to their critical role in both the innate response and in priming an adaptive immune response. Recently, much focus has been on generating highly cytotoxic NK cells for use in adoptive cell therapy and combinatorial immune-oncology therapies. The robust cytotoxicity against cancer cells and NK cell activation relies on fine tuning of activating and inhibitory signals. NK cell inhibitory receptors are often upregulated upon stimulation and activation and can be a marker for exhaustion. One of the major NK inhibitory receptors, T-cell immunoglobulin and ITIM domain (TIGIT), is highly expressed in ex vivo expanded NK cells. In this study, we will investigate if knockout of TIGIT in ex vivo expanded NK cells will enhance their anti-tumor activity.

Methods

CRISPR was used to make a targeted TIGIT knockout (KO) in ex vivo expanded NK cells. TIGIT KO NK cells were then compared to wild type NK cells to determine any changes in phenotypic markers. IFNγ, TNFα, and the degranulation marker CD107a expression were analyzed after co-culture with cancer cells. Cytotoxicity of TIGIT KO NK cells was compared to wild type NK cells against multiple different cancer cell spheroids using a kinetic live-cell imaging assay. Multiple NK cell:target cell ratios were analyzed over time to determine killing half-time and maximum killing. Data were fit to dose-response curves to determine cytotoxicity EC50 values.

Results

CRISPR was used to efficiently knockout TIGIT in ex vivo expanded NK cells and decreased expression levels to less than 5%. After co-culture with Raji cells expressing the TIGIT ligand PVR (CD155), TIGIT KO NK cells showed increased expression of IFNγ, TNFα and CD107a. TIGIT KO NK cells showed improved killing compared to wild type NK cells. TIGIT KO cells killed more target cells faster with significant decreases in half-killing time and more than a 2-fold decrease in EC50 cytotoxicity values in 3D spheroid cytotoxicity models against six different cancer cell lines. When NK cell:target cell ratios were low, the maximum cytotoxicity was also significantly higher in TIGIT KO cells.

Conclusions

Knockout of the TIGIT gene in ex vivo expanded NK cells resulted in higher functioning NK cells with increased cytokine expression, degranulation, and cytotoxicity against multiple cancer cell lines. These TIGIT knockout NK cells with improved antitumor activity provide a promising universal effector population with the potential for enhanced therapeutic efficacy.

Acknowledgements

We thank FL DOH Grant #9JK04 for funding and MaxCyte for providing instrument for testing.

Abstract 2390: LncRNA PAINT promotes prostate cancer progression through modulation of genes involved in epithelial-mesenchymal transition and apoptosis

Long non-coding RNAs (LncRNAs) play regulatory roles in cellular processes and their aberrant expression may drive cancer progression. Here we report the function of a LncRNA PAINT (Prostate Cancer-Associated Intergenic Non-Coding Transcript) in promoting prostate cancer (PCa) progression. Upregulation of PAINT expression was noted in the advanced stage and metastatic PCa patient tissues and correlated with poor survival. Inhibition of PAINT decreased cell proliferation, S-phase progression, increased expression of apoptotic markers, and improved sensitivity to docetaxel and Aurora kinase inhibitor VX-680. Inhibition of PAINT also decreased cell migration and reduced expression of mesenchymal markers, Slug, and Vimentin. Ectopic expression of PAINT suppressed E-cadherin, increased S-phase progression, and cell migration. PAINT expression in PCa cells also induced larger colony formation and higher expression of mesenchymal markers. Transcriptome profiling of PCa cells overexpressing PAINT showed differential expression of genes involved in epithelial-mesenchymal transition (EMT), apoptosis, and drug resistance which were further validated by qRT-PCR analysis. Additionally, GO enrichment and KEGG pathway analysis revealed altered expression of multiple pathways including p53 signaling and drug metabolism pathways indicating that PAINT may promote an oncogenic environment by simultaneously regulating various biological processes in PCa. In summary, our findings establish the role of PAINT as an oncogene in PCa and indicate the clinical significance of PAINT as a diagnostic marker and a possible therapeutic target for aggressive PCa.

Citation Format: Kavya Ganapathy, Md Faqrul Hasan, Jiao Sun, Ayman Khatib, Thomas Andl, Julia Soulakova, Domenico Coppola, Wei Zhang, Ratna Chakrabarti. LncRNA PAINT promotes prostate cancer progression through modulation of genes involved in epithelial-mesenchymal transition and apoptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2390.

LncRNA PAINT is associated with aggressive prostate cancer and dysregulation of cancer hallmark genes

Long noncoding RNAs (lncRNAs) play regulatory role in cellular processes and their aberrant expression may drive cancer progression. Here we report the function of a lncRNA PAINT (prostate cancer associated intergenic noncoding transcript) in promoting prostate cancer (PCa) progression. Upregulation of PAINT was noted in advanced stage and metastatic PCa. Inhibition of PAINT decreased cell proliferation, S-phase progression, increased expression of apoptotic markers, and improved sensitivity to docetaxel and Aurora kinase inhibitor VX-680. Inhibition of PAINT decreased cell migration and reduced expression of Slug and Vimentin. Ectopic expression of PAINT suppressed E-cadherin, increased S-phase progression and cell migration. PAINT expression in PCa cells induced larger colony formation, increased tumor growth and higher expression of mesenchymal markers. Transcriptome analysis followed by qRT-PCR validation showed differentially expressed genes involved in epithelial mesenchymal transition (EMT), apoptosis and drug resistance in PAINT-expressing cells. Our study establishes an oncogenic function of PAINT in PCa.

Abstract 274: Multifaceted function of microRNA-299-3p fosters an antitumor environment through modulation of androgen receptor and VEGFA signaling pathways in prostate cancer cells

MicroRNAs (miRNAs) play crucial roles in the regulation of prostate cancer (PCa) through modulation of signaling pathways. Androgen receptor (AR) signaling is central to PCa and PCa therapy. The therapeutic suitability of miRNAs that target AR has not been investigated thoroughly. Here, we illustrate the clinical relevance, functional significance and therapeutic benefit of miR-299-3p, an AR targeting microRNA, in PCa progression. We noted a loss of expression of miR-299-3p in prostate tumors compared to noncancerous prostate tissue in clinical specimens. Studies on the impact of miR-299-3p restoration on AR function, phenotypic changes associated with cancer progression and involvement of the downstream components of the AR signaling pathway were conducted using in vitro and in vivo model systems. Replenishment of miR-299-3p in C4-2B, 22Rv-1, and PC-3 cells contributed to cell cycle arrest, reduced cell proliferation, migration and increased expression of apoptotic markers. Additionally, expression of miR-299-3p reduced AR, PSA and VEGFA expression. AGO-RNA pulldown experiment showed enrichment of AR, VEGFA and miR-299-3p in the RISC in the extracts of C4-2B cells overexpressing miR-299-3p. Overexpression of miR-299-3p inhibited epithelial-mesenchymal transition signaling, through inhibition of expression of Slug, TGF-Β3, phospho-AKT, and phospho-PRAS40 and up-regulation of E-cadherin. Replenishment of miR-299-3p showed reduced tumor growth in xenograft mice models. Furthermore, we also tested the benefit of miR-299-3p restoration in combination treatment with enzalutamide and docetaxel which showed a synergistic effect on drug sensitivity. In conclusion, this study has identified novel mechanisms of antitumor and antimigration functions of miR-299-3p through modulation of AR and VEGFA signaling pathways which leads to improved drug sensitivity of PCa.

Citation Format: Kavya Ganapathy, Stephen Staklinski, Md Faqrul Hasan, Richard Ottman, Thomas Andl, Anders Berglund, Jong Park, Ratna Chakrabarti. Multifaceted function of microRNA-299-3p fosters an antitumor environment through modulation of androgen receptor and VEGFA signaling pathways in prostate cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 274.

Multifaceted Function of MicroRNA-299-3p Fosters an Antitumor Environment Through Modulation of Androgen Receptor and VEGFA Signaling Pathways in Prostate Cancer

Prostate cancer (PCa) is one of the most common cancers to affect men worldwide. Androgen receptor (AR) signaling is central to PCa and PCa therapy. MicroRNAs (miRNAs) play crucial roles in the regulation of prostate cancer through modulation of signaling pathways. In the present study, we illustrate the functional significance and therapeutic benefit of miR-299-3p, an AR targeting microRNA, in PCa progression. We noted loss of expression of miR-299-3p in prostate tumors compared to noncancerous prostate tissues. Replenishment of miR-299-3p in C4-2B, 22Rv-1 and PC-3 cells contributed to cell cycle arrest, reduced proliferation, migration and increased expression of apoptotic markers. Additionally, overexpression of miR-299-3p induced a reduction of AR, PSA and VEGFA expression. AGO-RNA pulldown experiment showed enrichment of AR, VEGFA and miR-299-3p in C4-2B cells overexpressing miR-299-3p. miR-299-3p overexpression also inhibited epithelial mesenchymal transition, expression of Slug, TGF-β3, phospho-AKT and phospho-PRAS40, but increased expression of E-cadherin. Furthermore, miR-299 overexpression resulted in reduced tumor growth in xenograft models and increased drug sensitivity. Overall, this study has identified novel mechanisms of antitumor and antimigration function of miR-299-3p through modulation of AR and VEGFA signaling pathways which lead to improved drug sensitivity of PCa.

Expression of FGD4 positively correlates with the aggressive phenotype of prostate cancer

BACKGROUND

FGD4 (Frabin) is an F-actin binding protein with GTP/GDP exchange activity specific for CDC42. It is involved in reorganization of the actin cytoskeleton, which requires both actin binding and CDC42 activating function of FGD4. Expression of FGD4 is altered in patients with heterogeneous hereditary motor and sensory neuropathies as a result of demyelination of peripheral nerves.

METHODS

In this study, we examined the expression of FGD4 in prostate cancer specimens using immunohistochemistry and studied the function of FGD4 in maintaining cell phenotype, behavior and drug sensitivity using overexpression and siRNA-based silencing approaches. We used Mann-Whitney test for comparative analysis of FGD4 expression.

RESULTS

Our results show that the expression of FGD4 is upregulated in cancerous prostates compared to the luminal cells in benign prostatic hyperplasia, although the basal cells showed high staining intensities. We noted a gradual increase in the staining intensity of FGD4 with increasing aggressiveness of the disease. Inhibition of expression of FGD4 using siRNAs showed reduced proliferation and cell cycle arrest in G2/M phase of androgen dependent LNCaP-104S and androgen refractory PC-3 cells. Inhibition of FGD4 also resulted in reduced cell migration and CDC42 activities in PC-3 cells whereas, ectopic expression of FGD4 induced cell migration, altered expression of mesenchymal and epithelial markers and activation of CDC42/PAK signaling pathway. Reduced expression of FGD4 improved sensitivity of LNCaP-104S cells to the anti-androgen drug Casodex and PC-3 cells to the microtubule stabilizing drug docetaxel.

CONCLUSIONS

Our data demonstrate a tumor promoting and a cell migratory function of FGD4 in prostate cancer cells and that inhibition of FGD4 expression enhances the response for both androgen-dependent and independent prostate cancer cells towards currently used prostate cancer drugs.

Abstract LB-325: Tumor suppressor effects of miR-17-92a cluster miRNAs on prostate cancer

MicroRNAs in miR-17-92a cluster are transcribed from a polycistronic transcription unit C13orf25 that generates six mature miRNAs, miR-17, miR-18a, miR-19a, miR- 19b, miR-20a. These miRNAs are reported to be overexpressed in colon and lung cancers, however, we noted a loss of expression of all members of this miR cluster in prostate cancer tissues compared to uninvolved tissues and in aggressive prostate cancer cells. In this study, we show that replenishment of miR-17-92a cluster as a whole showed antiproliferative effects, reduced activation of AKT and MAP kinases, delayed tumorigenicity and reduced tumor growth. Analysis of the expression of mRNA targets showed reduced expression of cell cycle regulatory proteins cyclin D1 and SSH1; and LIMK1 and FGD4 of RhoGTPase signaling pathway through direct targeting. miR-17-92 cluster expression also inhibited EMT via reduced cell migration and expression of mesenchymal markers while elevating expression and surface localization of the epithelial marker E-Cadherin. miR-17-92a miRNAs improved sensitivity of androgen dependent LNCaP 104-S prostate cancer cells to anti-androgen drug Casodex, AKT inhibitor MK-2206 2HCl, and docetaxel. The androgen refractory PC-3 cells also showed increased sensitivity to docetaxel, MK-2206 2HCl and Aurora kinase inhibitor VX680 upon ectopic expression of miR-17-92a cluster miRNAs. RNA seq analysis of prostate cancer cells expressing miR-17-92a cluster revealed altered expression of a number of oncogenic and tumor suppressor mRNAs, and noncoding RNAs, which may have implications in the altered phenotype of these cells. Our data demonstrate a tumor suppressor effect of miR-17-92a cluster miRNAs in prostate cancer cells and restoration of expression of these miRNAs has a therapeutic benefit for both androgen-dependent and -independent prostate cancer cells.

Note: This abstract was not presented at the meeting.

Citation Format: Ratna Chakrabarti, Richard Ottman, Md Faqrul Hasan. Tumor suppressor effects of miR-17-92a cluster miRNAs on prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-325. doi:10.1158/1538-7445.AM2017-LB-325

Molecular characterization of the virulent microorganisms along with their drug-resistance traits associated with the export quality frozen shrimps in Bangladesh

Current investigation characterized export quality shrimp samples in terms of pathogenic load along with the drug-resistance traits of the isolates, and detected the major virulent genes present in those isolates. Among the 30 such shrimp samples (15 each of Macrobrachium rosenbergi or Golda and Penaeus monodon or Bagda) studied, almost all were found to be contaminated with a huge load of bacteria (10⁶–10⁸ cfu/g) and fungi (10⁴–10⁵ cfu/g). Among the specific pathogens, presence of Escherichia coli, Vibrio spp., Aeromonas spp., Klebsiella spp., Shigella spp., Staphylococcus spp. and Listeria spp. were detected, of which most were likely to be resistant against commonly used antibiotics. Gene specific polymerase chain reaction (PCR) study revealed the presence of eae gene in E. coli, aero specific gene in Aeromonas spp., and sodB gene in Vibrio spp. Together with the huge extent of microbial contamination with a drug-resistance attribute, presence of such virulent genes further projects the probable public health risk upon consumption of the export quality shrimps.

Micropropagation of Centella asiatica L. An Important Medicinal Herb

High frequencies of multiple shoot regeneration were achieved from shoot tip explants cultured on MS media fortified with 4.0 mgl-1 BAP + 0.1 mgl-1 NAA. On an average 10.2?0.38 shoots per explant were obtained. The regenerated shoots were rooted in MS medium supplemented with 1.0 mgl-1 IBA. The in vitro grown plantlets were acclimatized and successfully transferred to natural condition with 80% survival. A reproducible protocol was established for in vitro propagation through multiple shoot induction of Centella asiatica L. an important medicinal herb having high medicinal value.DOI: http://dx.doi.org/10.3329/pa.v19i2.16928 Progress. Agric. 19(2): 51 - 56, 2008

Thelazia callipaeda infestation in Bangladesh: a case report

A 5 years old girl was admitted to Ophthalmology department of Mymensingh Medical College Hospital, Mymensingh with excessive watering, redness and movement of something in her right eye for last 2 months. She had unaided visual acuity- 6/6, matted eye lashes and mucoid discharge in right eye. Follicles were present on the fornices and lower palpebral conjunctiva of the same eye. On eversion of the right upper lid there were silicon tube like coiled moving structures seen at the lateral part of the upper fornics. Six nematodes were seen in the upper fornics around the duct of lacrimal glands. After removing the nematodes, one specimen was sent to parasitology department of Bangladesh Agriculture University for species identification. They reported that sending specimen is an adult "Thelazia Callipaeda". By the present study, the presence of human ocular T. callipaeda infestation is second reported case in Bangladesh. Ophthalmologists should be aware about parasitic infestation of conjunctiva.

Nanoparticle sensor for label free detection of swine DNA in mixed biological samples

We used 40 ± 5 nm gold nanoparticles (GNPs) as colorimetric sensor to visually detect swine-specific conserved sequence and nucleotide mismatch in PCR-amplified and non-amplified mitochondrial DNA mixtures to authenticate species. Colloidal GNPs changed color from pinkish-red to gray-purple in 2 mM PBS. Visually observed results were clearly reflected by the dramatic reduction of surface plasmon resonance peak at 530 nm and the appearance of new features in the 620-800 nm regions in their absorption spectra. The particles were stabilized against salt-induced aggregation upon the adsorption of single-stranded DNA. The PCR products, without any additional processing, were hybridized with a 17-base probe prior to exposure to GNPs. At a critical annealing temperature (55 °C) that differentiated matched and mismatched base pairing, the probe was hybridized to pig PCR product and dehybridized from the deer product. The dehybridized probe stuck to GNPs to prevent them from salt-induced aggregation and retained their characteristic red color. Hybridization of a 27-nucleotide probe to swine mitochondrial DNA identified them in pork-venison, pork-shad and venison-shad binary admixtures, eliminating the need of PCR amplification. Thus the assay was applied to authenticate species both in PCR-amplified and non-amplified heterogeneous biological samples. The results were determined visually and validated by absorption spectroscopy. The entire assay (hybridization plus visual detection) was performed in less than 10 min. The LOD (for genomic DNA) of the assay was 6 µg ml(-1) swine DNA in mixed meat samples. We believe the assay can be applied for species assignment in food analysis, mismatch detection in genetic screening and homology studies between closely related species.

Chronic hepatitis C in patients with sickle cell disease

OBJECTIVE

To determine the prevalence of hepatitis C virus (HCV) antibody in patients with sickle cell disease and to analyze the nature of chronic liver disease in these patients.

METHODS

A total of 99 patients attending a comprehensive sickle cell and thalassemia program at the Interfaith Medical Center, Brooklyn, NY, participated in the study. Eighty-five patients had sickle cell anemia (ss), eight had sickle C disease (sc), and six had sickle B thalassemia. History of blood transfusion, i.v. drug use, homosexuality, and alcohol abuse was obtained with a questionnaire and chart review. All patients were screened for HCV antibody by a first generation enzyme-linked immunosorbent assay. All positive results were confirmed with radioimmunoblot assay II (RIBA II). Patients were also checked for the presence of hepatitis B surface antigen. ALT levels were measured, and percutaneous liver biopsies were performed in patients positive for HCV antibody and greater than 1.5 times the normal ALT levels.

RESULTS

Antibody to HCV was detected in 10/99 patients (10.10%). Seven of 30 patients (23.33%) who received more than 10 U of packed red blood cells were positive for HCV antibody. Only 3/38 (7.9%) patients with less than 10 U of packed red blood cells in the past were positive for HCV antibody. None of the patients who never received blood transfusion were positive for HCV antibody (0/31 or 0%). A total of seven liver biopsies were performed in patients positive for HCV antibody. Two out of seven specimens (28.57%) showed significant liver damage. One revealed cirrhosis, and the other showed chronic active hepatitis. The remainder of liver biopsies (5/7; 71.42%) showed only mild portal inflammation.

CONCLUSIONS

The prevalence of HCV antibody is directly related to the number of blood transfusions in patients with sickle cell disease. Chronic HCV infection could be a major cause of cirrhosis of the liver in these patients.