Novel 2-Aminobenzothiazole Derivatives: Docking, Synthesis, and Biological Evaluation as Anticancer Agents.

Sixteen novel 2-aminobenzothiazole compounds with different amines or substituted piperazine moieties were designed, synthesized, and tested using various methods. Potential interactions were assessed by docking new compounds in the adenosine triphosphate (ATP) binding domain of the PI3Kγ enzyme (PDB code: 7JWE) by nucleophilic substitution or solvent-free/neat fusion for docked compound synthesis. Final 2-aminobenzothiazole compounds were characterized by direct probe gas chromatography-mass spectrometry (GC-MS), proton (1H-NMR), carbon-13 (13C-NMR), and attenuated total reflectance-infrared Fourier transform infrared (ATR FT-IR). The synthesized compounds were investigated for anticancer activities on lung cancer (A549) and breast cancer (MCF-7) cell lines. The compounds' PI3Kγ inhibition was evaluated at a 100 µM concentration. 4-Nitroaniline and piperazine-4-nitroaniline combination in OMS5 and OMS14 reduced lung and breast cancer cell line growth. IC50 values for OMS5 and OMS14, the strongest compounds, ranged from 22.13 to 61.03 µM. OMS1 and OMS2 inhibited PI3Kγ at the highest rates (47 and 48%, respectively) at a 100 µM concentration. Results show that the PI3Kγ enzyme suppression is not the main mechanism behind these OMS5 and OMS14 anticancer effects. CDK2, Akt, mTOR, and p42/44 MAPK are affected. EGF receptor suppression matters. AKT1, AKT3, CDK1/cyclin B, PDK1 direct, PIK3CA E542 K/PIK3R1 (p110 α/p85 α), PIK3CD/PIK3R1 (p110 δ/p85 α), and PKN inhibition were measured to evaluate the possible mechanism of compound OMS14. PIK3CD/PIK3R1 (p110 δ/p85 α) is the most, with 65% inhibition, suggesting a possible mechanism of anticancer properties. Furthermore, the NCI 60-cell line inhibition demonstrates promising broad anticancer inhibition against numerous cancer cell lines of OMS5 and OMS14, which could be good lead compounds for future development.

Niosomal Delivery of Celecoxib and Metformin for Targeted Breast Cancer Treatment.

Breast cancer continues to be a prominent worldwide health concern and requires continued investigation into innovative therapeutic approaches. Here, we report the first investigation into the therapeutic efficacy of combining Metformin (MET) and Celecoxib (CXB), both in free and niosomal form, for the treatment of breast cancer. Our investigation encompassed the characterization of these niosomal drug carriers, their stability assessment, and their effect on breast cancer cell models. The thin-film hydration technique was employed to prepare niosomes with spherical, uniform-size distributions and high encapsulation efficiencies. The niosomes were characterized by TEM, particle size analyzer, and ATR-FTIR. The niosomes with an average size of 110.6 ± 0.6 and 96.7 ± 0.7, respectively, for MET and CXB were stable when stored at 4 °C for three months with minimal drug leakage, minor changes in encapsulation efficiency and size, and unchanged physicochemical parameters. Evaluation in two-dimensional (2D) and three-dimensional (3D) viability assays demonstrated an increased cytotoxicity of encapsulated drugs when compared to their free-drug counterparts. Additionally, the combination of Metformin Niosomal Particles (MET NPs) and Celecoxib Niosomal Particles (CXB NPs) led to decreased cell viability in both 2D and 3D models compared to each drug administered individually. When comparing the effect of the niosomal versus the free combination of the drugs on cell migration, we found that both interventions effectively prevented cell migration. However, the efficacy of the niosomes' combination was not superior to that of the free drug combination (p < 0.05). In conclusion, the results of this study provide valuable insights into the potential application of combining MET and CXB nanoparticle delivery systems to breast cancer treatment. Exploring the in vivo application of this drug delivery system could open new avenues for more effective and targeted therapeutic approaches for breast cancer patients.

Novel Sulfonamide-Triazine Hybrid Derivatives: Docking, Synthesis, and Biological Evaluation as Anticancer Agents.

The biological benefits of trisubstituted 1,3,5-triazine derivatives include their ability to reduce inflammation and fight cancer. A unique series of sulfonamide-triazine hybrid molecules were produced chemically by synthesizing triazine derivatives utilizing the usual nucleophilic aromatic substitution of cyanuric chloride via the solvent-free/neat fusion method. Fourier-transform infrared spectroscopy (FTIR), 1H NMR, and 13C NMR spectroscopic analyses were used to identify novel trisubstituted synthetic compounds. The synthesized compounds have a moderate inhibition percentage when tested at 100 µM against the phosphoinositol 3-kinases (PI3Kα) enzyme; compounds 20 and 34 showed 46 and 68% anti-PI3Kα activity, respectively. To comprehend the anticipated interactions, the most successful compounds were subsequently docked into a PI3Kα protein's binding site (PDB code: 6OAC, resolution: 3.15 Å). The final synthetic compounds' anticancer activity was tested on the breast (MCF-7) and lung (A549) cancer cell lines at doses of 100 and 50 µM for additional evaluation of anticancer characteristics. The IC50 values for the sulfaguanidine-triazine derivatives 27, 28, 29, 31, and 35 ranged from 14.8 to 33.2 µM, showing that compounds containing sulfaguanidine and diethylamine in their structures significantly inhibited the activity. Compound 34 could be a promising lead compound for developing new target-selected anticancer compounds with low toxicity and high selectivity.

Development and Evaluation of an Innovative Approach Using Niosomes Based Polymeric Microneedles to Deliver Dual Antioxidant Drugs.

Ascorbic acid (AA) and caffeine (CAFF) work to protect cells from ultraviolet (UV) radiation and slow down the photoaging process of the skin. However, cosmetic application of AA and CAFF is limited due to poor penetration across the skin and rapid oxidation of AA. The aim of this study was to design and evaluate the dermal delivery of dual antioxidants utilizing microneedles (MNs) loaded with AA and CAFF niosomes. The niosomal nanovesicles were prepared using the thin film method and had particle sizes ranging from 130.6-411.2 nm and a negative Zeta potential of around -35 mV. The niosomal formulation was then combined with polyvinylpyrrolidone (PVP) and polyethylene glycol 400 (PEG 400) to create an aqueous polymer solution. The best skin deposition of AA and CAFF was achieved with the formulation containing 5% PEG 400 (M3) and PVP. Furthermore, the role of AA and CAFF as antioxidants in preventing cancer formation has been well-established. Here we validated the antioxidant properties of ascorbic acid (AA) and caffeine (CAFF) in a novel niosomal formulation referred to as M3 by testing its ability to prevent H2O2-indued cell damage and apoptosis in MCF-7 breast cancer cells. Results showed that M3 was able to shield MCF-7 cells from H2O2 induced damage at concentrations below 2.1 µg/mL for AA and 1.05 µg/mL for CAFF, and also exhibited anticancer effects at higher concentrations of 210 µg/mL for AA and 105 µg/mL. The formulations were stable for two months at room temperature in terms of moisture and drug content. The use of MNs and niosomal carriers could be a promising approach for dermal delivery of hydrophilic drugs like AA and CAFF.

Preparation and Characterization of Patch Loaded with Clarithromycin Nanovesicles for Transdermal Drug Delivery.

Clarithromycin (CLR), categorized as a Biopharmaceutical Classification System class II drug, has several gastrointestinal tract side effects and an extremely unpalatable bitter taste. The current study aimed to design transdermal patch-embedded CLR niosomes to overcome the aforementioned CLR-related challenges. Various niosomal formulations were successfully fabricated and characterized for their morphology, size, in vitro release, and antimicrobial efficacy. Subsequently, the CLR niosomes were loaded into transdermal patches using the solvent casting method. The polydispersity index of the niosomes ranged from 0.005 to 0.360, indicating the uniformity of the niosomes. The encapsulating efficiency (EE)% varied from 12 to 86%. The optimal Chol: surfactant ratio for drug release was found to be 0.5:1. In addition, the encapsulation of CLR into niosomal nanovesicles did not reduce the antibacterial activity of the CLR. The niosomal patch had a significantly higher permeability coefficient of CLR than the conventional patch. In addition to that, a shear-thinning behavior was observed in the niosomal gels before loading them into a niosomal patch. The flux (Jss) of the niosomal patch was significantly higher than the conventional patch by more than 200 times. In conclusion, niosome-based transdermal patches could be a promising method for the transdermal drug delivery of class II drugs and drugs experiencing GIT side effects.

Discovery of new PKN2 inhibitory chemotypes via QSAR-guided selection of docking-based pharmacophores.

Serine/threonine-protein kinase N2 (PKN2) plays an important role in cell cycle progression, cell migration, cell adhesion and transcription activation signaling processes. In cancer, however, it plays important roles in tumor cell migration, invasion and apoptosis. PKN2 inhibitors have been shown to be promising in treating cancer. This prompted us to model this interesting target using our QSAR-guided selection of docking-based pharmacophores approach where numerous pharmacophores are extracted from docked ligand poses and allowed to compete within the context of QSAR. The optimal pharmacophore was sterically-refined, validated by receiver operating characteristic (ROC) curve analysis and used as virtual search query to screen the National Cancer Institute (NCI) database for new promising anti-PKN2 leads of novel chemotypes. Three low micromolar hits were identified with IC50 values ranging between 9.9 and 18.6 µM. Pharmacological assays showed promising cytotoxic properties for active hits in MTT and wound healing assays against MCF-7 and PANC-1 cancer cells.

Formulation and Evaluation of Azithromycin-Loaded Niosomal Gel: Optimization, In Vitro Studies, Rheological Characterization, and Cytotoxicity Study.

Several novel, innovative approaches for improving transdermal delivery of BCS class III drugs have been proposed. Despite their great aqueous solubility, BCS class III drugs have the drawback of limited permeability. The objective of the current work was to screen the suitability of niosomes as a nanocarrier in permeation enhancement of azithromycin (AZM) transdermal delivery. Niosomes were prepared by an ether injection method using a nonionic surfactant (Span 60) and cholesterol at different concentrations. The ζ potential (ZP), polydispersity index (PDI), and particle size (PS) of AZM-loaded niosomes were evaluated. The size of the niosomes was found to vary between 288 and 394 nm. The results revealed that the niosomes prepared in a ratio of 2:1 (Span 60: cholesterol) had larger vesicle sizes, but all of them were characterized by narrow size distributions (PDI <0.95). Niosomal gel was successfully prepared using different polymers. The appearance, pH, viscosity, and ex vivo drug release of niosomal gel formulations were all examined. The flow curves showed that the niosomal gel displayed lower viscosity values than its corresponding conventional gels. Niosomal and conventional gels exhibited a domination of the elastic modulus (G') over the viscous modulus (G″) (G'>G″) in the investigated frequency range (0.1-100 rad/s), indicating stable gels with more solid-like properties. Ex vivo skin permeation studies for the niosomal gel show 90.83 ± 3.19% of drug release in 24 h as compared with the conventional gel showing significantly lower (P < 0.001) drug release in the same duration (1.25 ± 0.12%). Overall, these results indicate that niosomal gel could be an effective transdermal nanocarrier for enhancing the permeability of AZM, a BCS class III drug. In conclusion, this study suggests that transdermal formulations of AZM in the niosomal gel were successfully developed and could be used as an alternative route of administration.

Genetic variation in the ADIPOQ gene and serum adiponectin increase the risk of bladder cancer.

Bladder cancer (BC) is the 10th most common cancer worldwide. Genetic studies estimated 30% heritability in BC risk. Adiponectin is an adipocytokine that has important roles in the regulation of energy metabolism. Recent evidence suggests dysregulation of adiponectin levels in BC tissues. Serum level of adiponectin is influenced by single nucleotide polymorphisms (SNPs) in the ADIPOQ gene. However, limited evidence is available regarding the association between adiponectin serum levels or SNPs in ADIPOQ and BC risk. This study aimed to assess whether adiponectin serum levels or SNPs in ADIPOQ may modify BC risk. In this case-control study, 114 BC patients were recruited along with 114 controls. Study subjects were genotyped for variations in ADIPOQ SNPs, namely rs17300539, rs266729, rs2241766, and rs1501299. Adiponectin levels were measured from the serum of study subjects. Our analysis showed that the G allele and the GG genotype of rs1501299 were significantly more frequent in BC patients compared to those in the control group (p-value < 0.05). Moreover, two ADIPOQ haplotypes containing the above G allele were associated with increased BC risk (p-value < 0.05). Multivariate analysis showed that increased serum adiponectin, smoking or age were all significant predictors of BC (p-value < 0.05). The data supports use of serum adiponectin and the G allele of rs1501299 SNP in ADIPOQ as potential biomarkers and/or targets in BC. To further validate findings in this study, larger populations of various ethnicities and/or genetic backgrounds are required. More investigations on the functional role of adiponectin in BC will also provide better understanding of potential targeting adiponectin for BC treatment.

Formulation and Evaluation of Niosomal Alendronate Sodium Encapsulated in Polymeric Microneedles: In Vitro Studies, Stability Study and Cytotoxicity Study.

The aim of this study is to design and evaluate a transdermal delivery system for alendronate sodium (ALS) loaded with nanocarrier to improve its permeability and prolong its release. This is due to its low bioavailability, potential gastrointestinal side effects, and the special administration needed for the oral dosage form of ALS. When using the ether injection method, various niosomal formulations were produced. Size of the particles, polydispersity index (PDI), surface charge (ZP), drug entrapment efficiency (EE), and in vitro release were used to characterize the resulting niosomes. The size of niosomes ranged between 99.6 ± 0.9 and 464.3 ± 67.6 nm, and ZP was from −27.6 to −42.27 mV. The niosomal formulation was then loaded to aqueous polymer solution of 30% polyvinyl pyrrolidone (PVP) (MN-1), 30% PVP with 15% poly(vinyl alcohol) (PVA) (2:1) (MN-2), and 30% PVP with 15% PVA (1:1) (MN-3). The cumulative amount of ALS (Q) was in the following order: MN-1 > MN-2 > MN-3. All formulations in this study were stable at room temperature over two months, in terms of moisture content and drug content. In conclusion, a transdermal delivery of ALS niosomes combined in microneedles (MNs) was successfully prepared to provide sustained release of ALS.

Prevalence and predictive factors for infertility-related stress among infertile couples: A cross-sectional study from Jordan and the occupied Palestinian territories.

OBJECTIVES: To assess the level of infertility-related stress, associated socio-economic, and demographic factors among infertile couples living in Jordan and those living under the chronic Israeli-Palestinian conflict in the occupied Palestinian territories. METHODS: A cross-sectional study was carried out in a number of fertility and reproductive clinics in Jordan and occupied Palestinian territories over a period of 6 months. Trained clinical pharmacists interviewed the identified couples. RESULTS: A total of 443 participants were interviewed. Three variables were significantly and independently associated with global stress scores. The need of parenthood appears higher in women than men among infertile couples in Jordan and Palestine (p=0.005). The country of origin (p<0.001) made the greatest contribution of unique variance followed by family type (p=0.035). Additionally, a significant contribution to the model was carried out by the number of clinicians who followed up on the case (p=0.013). The average total cost of treatment since the problem had been diagnosed was 2936±4529 Jordanian dinar, which may be of concern to both Jordanians and Palestinians given the limited resources available in developing nations. CONCLUSION: This study shows a significant degree of stress among infertile couples. The place of origin, family structure, and presence of medical insurance had a significant impact on the infertility global stress score. This study emphasizes the necessity for specific psychological therapies that are currently lacking in public healthcare practices in both Jordan and Palestine.

Prevalence and Predictive Factors of Masked Depression and Anxiety among Jordanian and Palestinian Couples: A Cross-Sectional Study.

Although anxiety and depression are among the most prevalent mental disorders worldwide, they continue to gain less attention than their physical counterparts in terms of health care provision and population mentalisation. This cross-sectional study explores and compares the national prevalence of depression and anxiety signs/symptoms and well as identifying associated socio-demographic factors among Jordanian and Palestinian fertile couples. Four-hundred and sixty-nine participants were eligible for inclusion and agreed to participate in the study. The mean score for HAM-A and BDI-II were 12.3 ± 8.2 and 15.30 ± 10.0, respectively. According to the grading of HAM-A and BDI-II, the majority of the participants have graded themselves to be mildly anxious (N = 323, 68.9%) and around one third of participants (N = 148, 31.6%) moderately to severe depressed. The suicidal intent was remarkable and of concern where around 18.6% of participants had suicidal thoughts and wishes. There was a significant correlation between both HAM-score and BDI-II score and age [p = 0.01, p = 0.011, respectively], body weight [p = 0.01, p = 0.006, respectively], and total monthly income [p < 0.001, p < 0.001, respectively]. Our findings ought to alert healthcare professionals and other interested parties that there is a high burden of anxiety and depression symptoms among Jordanian and Palestinian couples. To support Jordanian and Palestinian couples' mental health, healthcare professionals, researchers, and educators favoured to concentrate on creating efficient and culturally relevant education, preventive, and intervention procedures utilising evidence-based guidelines.

The Expression of Glutaminases and their Association with Clinicopathological Parameters in the Head and Neck Cancers.

BACKGROUND: The increased glutamine metabolism is a characteristic feature of cancer cells. The interconversion between glutamine and glutamate is catalyzed by two glutaminase isoforms, GLS1 and GLS2, which appear to have different roles in different types of cancer. We investigated for the first time the protein expression of GLS1 and GLS2, and their correlation with advanced clinicopathological parameters in head and neck cancers. METHODS: Consecutive slides from a tissue microarray comprised of 80 samples ranging from normal to metastatic were stained immunohistochemically for GLS1, GLS2, HIF-1α or CD147. Following analysis by two expert pathologists, we carried out a statistical analysis of the scores. RESULTS: GLS1 and GLS2 were found to be upregulated at the protein level in head and neck tumours compared to normal tissues, and this increased expression correlated positively (GLS1) and negatively (GLS2) with tumor grade, indicating a shift of expression between GLS enzyme isoforms based on tumor differentiation. Increased expression of GLS1 was associated with high CD147 expression, and elevated GLS2 expression was associated with both high CD147 and high HIF-1α expressions. The correlation of the GLS1 and GLS2 with HIF-1α or CD147 was strongly associated with more advanced clinicopathological parameters. CONCLUSION: The increased expression of GLS1 and GLS2 may be explored as a new treatment for head and neck cancers.

Evaluation of Jordan's citizens' awareness of the emerging Coronavirus (COVID-19) disease: A mixed analysis of the symptoms, transmission, and preventive measures.

This study aimed to evaluate Jordan citizens' awareness, knowledge, and practice concerning Coronavirus-19 (COVID-19) symptoms, routes of transmission, and preventive measures. An online self-administered questionnaire was filled out completely by participants (N = 328) from mainly four major cities in Jordan during the period beginning of May-end of September 2020. Participants' main sources of knowledge about COVID-19 were the government websites (87.8%), social media (87.5%), and Television (TV) (81.1%). The majority of participants valued the drizzle of cough from infected individuals (96.3%), direct contact with contaminated surfaces (91.5%), and direct contact with infected individuals (84.5%) as the highest rates of the route of transmission. The highest rates chosen as symptoms of COVID-19 viral infections were high-grade fever (99.1%), troublesome breathing (96.6%), coughing (92.7%), headache (91.2%), and loss of smell and taste (80.8%). The majority of participants (>92%) strongly agreed on the behavioral protective measures such as no face touching, wearing a mask, the use of alcoholic hand disinfectants, and the need for self-isolation. This study showed that the Jordanian citizens were aware of the epidemiology of COVID-19 and related infection preventive measures. This agrees well with the efforts done by the Ministry of health and governmental organizations to spread the necessary information about the virus among citizens.

CCR7 as a therapeutic target in Cancer.

The CCR7 chemokine axis is comprised of chemokine ligand 21 (CCL21) and chemokine ligand 19 (CCL19) acting on chemokine receptor 7 (CCR7). This axis plays two important but apparently opposing roles in cancer. On the one hand, this axis is significantly engaged in the trafficking of a number of effecter cells involved in mounting an immune response to a growing tumour. This suggests therapeutic strategies which involve potentiation of this axis can be used to combat the spread of cancer. On the other hand, the CCR7 axis plays a significant role in controlling the migration of tumour cells towards the lymphatic system and metastasis and can thus contribute to the expansion of cancer. This implies that therapeutic strategies which involve decreasing signaling through the CCR7 axis would have a beneficial effect in preventing dissemination of cancer. This dichotomy has partly been the reason why this axis has not yet been exploited, as other chemokine axes have, as a therapeutic target in cancer. Recent report of a crystal structure for CCR7 provides opportunities to exploit this axis in developing new cancer therapies. However, it remains unclear which of these two strategies, potentiation or antagonism of the CCR7 axis, is more appropriate for cancer therapy. This review brings together the evidence supporting both roles of the CCR7 axis in cancer and examines the future potential of each of the two different therapeutic approaches involving the CCR7 axis in cancer.

Application of small molecule FPR1 antagonists in the treatment of cancers.

The formylpeptide receptor-1 (FPR1) is a member of the chemotactic GPCR-7TM formyl peptide receptor family, whose principle function is in trafficking of various leukocytes into sites of bacterial infection and inflammation. More recently, FPR1 has been shown to be expressed in different types of cancer and in this context, plays a significant role in their expansion, resistance and recurrence. ICT12035 is a selective and potent (30 nM in calcium mobilisation assay) small molecule FPR1 antagonist. Here, we demonstrate the efficacy of ICT12035, in a number of 2D and 3D proliferation and invasion in vitro assays and an in vivo model. Our results demonstrate that targeting FPR1 by a selective small molecule antagonist, such as ICT12035, can provide a new avenue for the treatment of cancers.

Hypoxia modulates CCR7 expression in head and neck cancers.

BACKGROUND: The chemokine receptor CCR7 is expressed on lymphocytes and dendritic cells and is responsible for trafficking of these cells in and out of secondary lymphoid organs. It has recently been shown that CCR7 expression is elevated in a number of cancers, including head and neck cancers, and that its expression correlates to lymph node (LN) metastasis. However, little is known about the factors that can induce CCR7 expression in head and neck cancers. METHOD: We compared the protein expression and functional responses of CCR7 under normoxia and hypoxia in head and neck cancer cell lines OSC-19, FaDu, SCC-4, A-253 and Detroit-562 cultured as monolayers, spheroids, and grown in vivo as xenografts in balb/c mice. In addition, we analysed the correlation between hypoxia marker HIF-1α and CCR7 expression in a tissue microarray comprising 80 clinical samples with various stages and grades of malignant tumour and normal tissue. RESULTS: Under hypoxia, the expression of CCR7 is elevated in both in vitro and in vivo models. Furthermore, in malignant tissue, a correlation is observed between hypoxia marker HIF-1α and CCR7 across all clinical stages. This correlation is also strong in early histological grade of tumours. CONCLUSION: Hypoxia plays a role in the regulation of the expression of CCR7 and it may contribute to the development of a metastatic phenotype in head and neck cancers through this axis.

Agarose Spot as a Comparative Method for in situ Analysis of Simultaneous Chemotactic Responses to Multiple Chemokines.

We describe a novel protocol to quantitatively and simultaneously compare the chemotactic responses of cells towards different chemokines. In this protocol, droplets of agarose gel containing different chemokines are applied onto the surface of a Petri dish, and then immersed under culture medium in which cells are suspended. As chemokine molecules diffuse away from the spot, a transient chemoattractant gradient is established across the spots. Cells expressing the corresponding cognate chemokine receptors migrate against this gradient by crawling under the agarose spots towards their centre. We show that this migration is chemokine-specific; meaning that only cells that express the cognate chemokine cell surface receptor, migrate under the spot containing its corresponding chemokine ligand. Furthermore, we show that migration under the agarose spot can be modulated by selective small molecule antagonists present in the cell culture medium.

Polysialic acid sustains cancer cell survival and migratory capacity in a hypoxic environment.

Polysialic acid (polySia) is a unique carbohydrate polymer expressed on the surface of NCAM (neuronal cell adhesion molecule) in a number of cancers where it modulates cell-cell and cell-matrix adhesion, migration, invasion and metastasis and is strongly associated with poor clinical prognosis. We have carried out the first investigation into the effect of polySia expression on the behaviour of cancer cells in hypoxia, a key source of chemoresistance in tumours. The role of polysialylation and associated tumour cell migration and cell adhesion were studied in hypoxia, along with effects on cell survival and the potential role of HIF-1. Our findings provide the first evidence that polySia expression sustains migratory capacity and is associated with tumour cell survival in hypoxia. Initial mechanistic studies indicate a potential role for HIF-1 in sustaining polySia-mediated migratory capacity, but not cell survival. These data add to the growing body of evidence pointing to a crucial role for the polysialyltransferases (polySTs) in neuroendocrine tumour progression and provide the first evidence to suggest that polySia is associated with an aggressive phenotype in tumour hypoxia. These results have significant potential implications for polyST inhibition as an anti-metastatic therapeutic strategy and for targeting hypoxic cancer cells.

Study of the Chemotactic Response of Multicellular Spheroids in a Microfluidic Device.

We report the first application of a microfluidic device to observe chemotactic migration in multicellular spheroids. A microfluidic device was designed comprising a central microchamber and two lateral channels through which reagents can be introduced. Multicellular spheroids were embedded in collagen and introduced to the microchamber. A gradient of fetal bovine serum (FBS) was established across the central chamber by addition of growth media containing serum into one of the lateral channels. We observe that spheroids of oral squamous carcinoma cells OSC-19 invade collectively in the direction of the gradient of FBS. This invasion is more directional and aggressive than that observed for individual cells in the same experimental setup. In contrast to spheroids of OSC-19, U87-MG multicellular spheroids migrate as individual cells. A study of the exposure of spheroids to the chemoattractant shows that the rate of diffusion into the spheroid is slow and thus, the chemoattractant wave engulfs the spheroid before diffusing through it.