Targeted Biodegradable Near-Infrared Fluorescent Nanoparticles for Colorectal Cancer Imaging

Colorectal cancer (CRC) is the third leading cause of cancer death in the U.S., and early detection and diagnosis are essential for effective treatment. Current methods are inadequate for rapid detection of early disease, revealing flat lesions, and delineating tumor margins with accuracy and molecular specificity. Fluorescence endoscopy can generate wide field-of-view images enabling detection of CRC lesions and margins; increased signal intensity and improved signal-to-noise ratios can increase both speed and sensitivity of cancer detection. For this purpose, we developed targeted near-infrared (NIR) fluorescent silica nanoparticles (FSNs). We tuned their size to 50-200 nm and conjugated their surface with an antibody to carcinoembryonic antigen (CEA) to prepare CEA-FSNs. The physicochemical properties and biodegradable profiles of CEA-FSN were characterized, and molecular targeting was verified in culture using HT29 (CEA positive) and HCT116 (CEA negative) cells. CEA-FSNs bound to the HT29 cells to a greater extent than to the HCT116 cells, and smaller CEA-FSNs were internalized into HT29 cells more efficiently than larger CEA-FSNs. After intravenous administration of CEA-FSNs, a significantly greater signal was observed from the CEA-positive HT29 than the CEA-negative HCT116 tumors in xenografted mice. In F344-PIRC rats, polyps in the intestine were detected by white-light endoscopy, and NIR fluorescent signals were found in the excised intestinal tissue after topical application of CEA-FSNs. Immunofluorescence imaging of excised tissue sections demonstrated that the particle signals coregistered with signals for both CRC and CEA. These results indicate that CEA-FSNs have potential as a molecular imaging marker for early diagnosis of CRC.

Rural-Urban Differences in Prevalence and Associated Factors of Underweight and Overweight/Obesity among Bangladeshi Adults: Evidence from Bangladesh Demographic and Health Survey 2017-2018

The aim of this study was to identify the differences in prevalence and associated factors of underweight and overweight/obesity among Bangladeshi adults (≥18 years) by analyzing the cross-sectional Bangladesh Demographic and Health Survey 2017-2018 data. Multilevel multivariable logistic regression was applied to identify the factors associated with underweight and overweight/obesity in urban and rural areas. The prevalence of underweight was 12.24% and 19.34% in urban and rural areas, respectively. The prevalence of overweight/obesity was 50.23% and 35.96%, respectively, in urban and rural areas. In the final multivariable analysis in both urban and rural areas, 30-49 years of age, female sex, being educated up to college or higher level, living in the wealthiest household, and being currently married or being separated/divorced/widowed had higher odds of being overweight/obese compared to other categories. Residence in the Mymensingh and Sylhet region was associated with decreased odds of overweight/obesity in urban and rural areas. On the other hand, being educated up to college or higher level, living in the wealthiest household, and being married were associated with reduced odds of being underweight in both areas. These high-risk groups should be brought under targeted health promotion programs to curb malnutrition.

The Potential Role of Ionic Liquid as a Multifunctional Dental Biomaterial

In craniofacial research and routine dental clinical procedures, multifunctional materials with antimicrobial properties are in constant demand. Ionic liquids (ILs) are one such multifunctional intelligent material. Over the last three decades, ILs have been explored for different biomedical applications due to their unique physical and chemical properties, high task specificity, and sustainability. Their stable physical and chemical characteristics and extremely low vapor pressure make them suitable for various applications. Their unique properties, such as density, viscosity, and hydrophilicity/hydrophobicity, may provide higher performance as a potential dental material. ILs have functionalities for optimizing dental implants, infiltrate materials, oral hygiene maintenance products, and restorative materials. They also serve as sensors for dental chairside usage to detect oral cancer, periodontal lesions, breath-based sobriety, and dental hard tissue defects. With further optimization, ILs might also make vital contributions to craniofacial regeneration, oral hygiene maintenance, oral disease prevention, and antimicrobial materials. This review explores the different advantages and properties of ILs as possible dental material.

Flavinated SDHA underlies the change in intrinsic optical properties of oral cancers

The molecular basis of reduced autofluorescence in oral squamous cell carcinoma (OSCC) cells relative to normal cells has been speculated to be due to lower levels of free flavin adenine dinucleotide (FAD). This speculation, along with differences in the intrinsic optical properties of extracellular collagen, lies at the foundation of the design of currently-used clinical optical detection devices. Here, we report that free FAD levels may not account for differences in autofluorescence of OSCC cells, but that the differences relate to FAD as a co-factor for flavination. Autofluorescence from a 70 kDa flavoprotein, succinate dehydrogenase A (SDHA), was found to be responsible for changes in optical properties within the FAD spectral region, with lower levels of flavinated SDHA in OSCC cells. Since flavinated SDHA is required for functional complexation with succinate dehydrogenase B (SDHB), decreased SDHB levels were observed in human OSCC tissue relative to normal tissues. Accordingly, the metabolism of OSCC cells was found to be significantly altered relative to normal cells, revealing vulnerabilities for both diagnosis and targeted therapy. Optimizing non-invasive tools based on optical and metabolic signatures of cancers will enable more precise and early diagnosis leading to improved outcomes in patients.

Flavinated SDHA Underlies the Change in Intrinsic Optical Properties of Oral Cancers

The molecular basis of reduced autofluorescence in oral squamous cell carcinoma (OSCC) cells relative to normal cells has been speculated to be due to lower levels of free flavin adenine dinucleotide (FAD). This speculation, along with differences in the intrinsic optical properties of extracellular collagen, lie at the foundation of the design of currently-used clinical optical detection devices. Here, we report that free FAD levels may not account for differences in autofluorescence of OSCC cells, but that the differences relate to FAD as a co-factor for flavination. Autofluorescence from a 70 kDa flavoprotein, succinate dehydrogenase A (SDHA), was found to be responsible for changes in optical properties within the FAD spectral region with lower levels of flavinated SDHA in OSCC cells. Since flavinated SDHA is required for functional complexation with succinate dehydrogenase B (SDHB), decreased SDHB levels were observed in human OSCC tissue relative to normal tissues. Accordingly, the metabolism of OSCC cells was found to be significantly altered relative to normal cells, revealing vulnerabilities for both diagnosis and targeted therapy. Optimizing non-invasive tools based on optical and metabolic signatures of cancers will enable more precise and early diagnosis leading to improved outcomes in patients.

Obesity and Abdominal Obesity in Indian Population: Findings from a Nationally Representative Study of 698,286 Participants

This study aims to determine and compare the prevalence and correlates of obesity and abdominal obesity in India among participants aged 18-54 years. Data were acquired from the nationally representative National Family Health Survey 2019-21. Age and sex standardized descriptive analyses were conducted to determine the prevalence of obesity and abdominal obesity, and multivariable multilevel logistic regression was performed to identify the factors associated with these conditions. Gender-specific analyses were also conducted. The sample weight was adjusted throughout. The final sample size for this study was 698,286. The prevalence of obesity and abdominal obesity was 13.85% and 57.71%, respectively. Older age, being female, increased educational status and increased wealth index, being married at any point, and residing in an urban area all increased the odds of both obesity and abdominal obesity. Being a resident of the North zone and having a current alcohol intake increased the odds of abdominal obesity. On the other hand, being a resident of the South zone of India increased the odds of obesity. Targeting these high-risk groups can be a strategy for public health promotion programs.

Harnessing insect olfactory neural circuits for detecting and discriminating human cancers

There is overwhelming evidence that presence of cancer alters cellular metabolic processes, and these changes are manifested in emitted volatile organic compound (VOC) compositions of cancer cells. Here, we take a novel forward engineering approach by developing an insect olfactory neural circuit-based VOC sensor for cancer detection. We obtained oral cancer cell culture VOC-evoked extracellular neural responses from in vivo insect (locust) antennal lobe neurons. We employed biological neural computations of the antennal lobe circuitry for generating spatiotemporal neuronal response templates corresponding to each cell culture VOC mixture, and employed these neuronal templates to distinguish oral cancer cell lines (SAS, Ca9-22, and HSC-3) vs. a non-cancer cell line (HaCaT). Our results demonstrate that three different human oral cancers can be robustly distinguished from each other and from a non-cancer oral cell line. By using high-dimensional population neuronal response analysis and leave-one-trial-out methodology, our approach yielded high classification success for each cell line tested. Our analyses achieved 76-100% success in identifying cell lines by using the population neural response (n = 194) collected for the entire duration of the cell culture study. We also demonstrate this cancer detection technique can distinguish between different types of oral cancers and non-cancer at different time-matched points of growth. This brain-based cancer detection approach is fast as it can differentiate between VOC mixtures within 250 ms of stimulus onset. Our brain-based cancer detection system comprises a novel VOC sensing methodology that incorporates entire biological chemosensory arrays, biological signal transduction, and neuronal computations in a form of a forward-engineered technology for cancer VOC detection.

Oral Healthcare during Pregnancy: Its Importance and Challenges in Lower-Middle-Income Countries (LMICs)

Oral health is essential in general health and well-being to maintain overall quality of life [...].

Differences in Prevalence and Associated Factors of Underweight and Overweight/Obesity among Bangladeshi Adults by Gender: Analysis of a Nationally Representative Survey

The objective of this study was to find the differences in prevalence and associated factors of underweight and overweight/obesity among Bangladeshi adults by gender, using the nationally representative Bangladesh Demographic and Health Survey 2017-2018 data. To identify the factors associated with underweight and overweight/obesity in both genders, multilevel multivariable logistic regression was conducted. The prevalence of underweight was 19.79% and 15.49% among males and females, respectively. The prevalence of overweight/obesity was 32.67% and 45.60% among males and females, respectively. Among both genders, participants with the highest likelihood of overweight/obesity were aged 30-49 years and 50-69 years, had the highest educational attainment up to primary and secondary level, resided in a household that belonged to the middle, richer, or richest wealth quintiles, and were currently married. On the other hand, among both genders, increased educational attainment and wealth index were inversely associated with being underweight. Health promotion programs in Bangladesh should focus on these high-risk groups to address the burden of underweight and overweight/obesity.

Implants with Sensing Capabilities

Because of the aging human population and increased numbers of surgical procedures being performed, there is a growing number of biomedical devices being implanted each year. Although the benefits of implants are significant, there are risks to having foreign materials in the body that may lead to complications that may remain undetectable until a time at which the damage done becomes irreversible. To address this challenge, advances in implantable sensors may enable early detection of even minor changes in the implants or the surrounding tissues and provide early cues for intervention. Therefore, integrating sensors with implants will enable real-time monitoring and lead to improvements in implant function. Sensor integration has been mostly applied to cardiovascular, neural, and orthopedic implants, and advances in combined implant-sensor devices have been significant, yet there are needs still to be addressed. Sensor-integrating implants are still in their infancy; however, some have already made it to the clinic. With an interdisciplinary approach, these sensor-integrating devices will become more efficient, providing clear paths to clinical translation in the future.

Highlights on Advancing Frontiers in Tissue Engineering

The field of tissue engineering continues to advance, sometimes in exponential leaps forward, but also sometimes at a rate that does not fulfill the promise that the field imagined a few decades ago. This review is in part a catalog of success in an effort to inform the process of innovation. Tissue engineering has recruited new technologies and developed new methods for engineering tissue constructs that can be used to mitigate or model disease states for study. Key to this antecedent statement is that the scientific effort must be anchored in the needs of a disease state and be working toward a functional product in regenerative medicine. It is this focus on the wildly important ideas coupled with partnered research efforts within both academia and industry that have shown most translational potential. The field continues to thrive and among the most important recent developments are the use of three-dimensional bioprinting, organ-on-a-chip, and induced pluripotent stem cell technologies that warrant special attention. Developments in the aforementioned areas as well as future directions are highlighted in this article. Although several early efforts have not come to fruition, there are good examples of commercial profitability that merit continued investment in tissue engineering. Impact statement Tissue engineering led to the development of new methods for regenerative medicine and disease models. Among the most important recent developments in tissue engineering are the use of three-dimensional bioprinting, organ-on-a-chip, and induced pluripotent stem cell technologies. These technologies and an understanding of them will have impact on the success of tissue engineering and its translation to regenerative medicine. Continued investment in tissue engineering will yield products and therapeutics, with both commercial importance and simultaneous disease mitigation.

Abstract LB243: Implantable and insertable miniature dual-axis confocal (DAC) microscope to detect epithelial-mesenchymal transition (EMT) in the breast cancer microenvironment

The tumor microenvironment (TME) can be defined as non-transformed stromal elements within the tumor, effecting their growth, invasion, and metastatic ability. Cancer cells leave the primary tumor during metastasis, then spread and colonize in distant organs. In breast cancer, metastasis mechanisms are not yet fully understood within the TME. However, epithelial to mesenchymal transition (EMT) is a known essential step in metastasis, in which patterned epithelial cells transform into migratory cells with mesenchymal phenotypes. Developing state-of-the-art multiparametric in vivo imaging devices increases the opportunities to observe dynamic cellular properties and their interactions with the surrounding stroma and TME during the critical steps of invasion and metastasis. Currently available commercial imaging technologies only enable in vivo imaging under anesthesia in a fixed posture. In contrast, real-time confocal imaging of the EMT and TME is not possible in animals. We have adapted our miniature dual-axis confocal (DAC) fluorescent microscope to track breast cancer cells having fluorescent reporters indicating key molecular splicing events during EMT to overcome these limitations. This project aims to study EMT more thoroughly using rat breast cancer MTLn3 cell lines by mimicking in vivo scenarios through 3D in vitro mono/co-culture spheroids, 3D multi-spheroid matrix overlay models, and 3D sandwich. We have engineered MTLn3 cells with fluorescent reporters correlating with different EMT stages, depending on their invasiveness levels. The ultra-low attachment method is used to engineer 3D MTLn3 spheroids, embed within TME matrices, and monitor advanced in vitro live-cell imaging techniques for up to 10 days. Another goal is to use miniature DAC microscopes, implanted in animal models, to study the fundamental changes occurring during carcinoma progression. This transdisciplinary project's final goal is to optimize the DAC microscope as an implantable and insertable device to investigate EMT-associated splicing events in the TME of orthotopic rat breast carcinoma models. This will be achieved by growing engineered MTLn3 cells and spheroids in their mammary fat pads and following microscopic changes for a certain period. This work will contribute to further developing the miniature implantable DAC microscopes for 3D high resolution, multiparametric imaging to reveal dynamic changes within the TME during carcinoma progression.

Citation Format: Ehsanul Hoque Apu, Seock-Jin Chung, Michael J. Mandella, Frank Schonig, Frank B. Gertler, Zhen Qiu, Christopher H. Contag. Implantable and insertable miniature dual-axis confocal (DAC) microscope to detect epithelial-mesenchymal transition (EMT) in the breast cancer microenvironment [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 LB243.

Exploring the knowledge, awareness and practices of COVID-19 among dentists in Bangladesh: A Cross-sectional Investigation

Background: COVID-19 pandemic has caused an unpre-cedented strike on humanity around the world . The scenario in Bangladesh is getting worse day by day, and every aspect of the society is observing its impact. Health care professionals are at a greater risk of contracting the disease while caring for patients. Objective: The research objective is to explore knowledge, awareness, and practices of registered dentists regarding COVID-19 epidemiology and transmission during the rapid outbreak of this highly contagious virus in Bangladesh. Material and Methods: A cross-sectional web-based survey was conducted among the dentists who were enrolled with their valid unique Bangladesh Medical and Dental Council (BMDC) registration number. A structured questionnaire was distributed among the dentists through different social media platforms. A total of 184 dentists participated in the survey between March and April 2020. Both descriptive analysis and multivariable logistic regression analysis was performed. Results: The dentists' mean age was 31.75 years, with a standard deviation of 6.5 years. About 29.3% of dentists completed their postgraduate qualification, and 76% of them were engaged in private practice at the time of data collection. Compared to the dentists with undergraduate education, the dentists with a postgraduate education are three times (OR=3.1, 95%CI 1.2-7.9 and over 5 times (OR=5.3, 95% CI: 1.2-23.3) more likely to have) better knowledge and practices toward COVID-19 respectively. Dentists aged 26-30 years are less likely to have good practices than the younger dentists (OR: .1; 95% CI: .01-.5). However, dentists with less than five years experience are 10.3 (1.6-68.9) times more likely to have good practices compared to the dentists with more experience. Conclusion: Majority of the dentists from Bangladesh have shown good knowledge, awareness, and practice regarding COVID-19. We recommend that the healthcare authorities, professional organizations, and hospitals coordinate, and conduct mandatory advanced infectious disease training for all the practicing dentists in the country.

Depression among the Non-Native International Undergraduate Students Studying Dentistry in Bangladesh

BACKGROUND

Bangladesh has been attracting international students with interests in various subjects recently. Every year students from different parts of the world come to study undergraduate and postgraduate courses, mostly at private universities in Bangladesh. This study evaluates the depression status among international students who are studying dentistry in Bangladesh.

METHODS

This cross-sectional survey was conducted among International undergraduate dental students who enrolled in the Bachelor of Dental Surgery program in nine public and private dental colleges in Bangladesh. Participants were selected using a convenience sampling method. A total of 206 students completed the survey where 78.5% of them were female students and 21.5% students were male, and a CES-D 10-item Likert scale questionnaire was used for data collection. The Cronbach alpha for the 10-item CES-D scale for this population is 0.812.

RESULTS

The majority of the students (79.5%) are below 24 years of age with a mean age of 23.22 years and standard deviation of 2.3, and are students who cannot communicate well in Bengali (Bangla), about 60% of them have experienced depression. About 77.3% (p < 0.00) of the international students having financial difficulties exhibited depression. The international students who went through financial problems were two times more likely to suffer from depression (OR = 2.38; p-value < 0.01).

CONCLUSION

This study tried to highlight the struggles faced by international students in Bangladesh studying dentistry. It is evident from the findings that several factors influence students' mental well-being during demanding dental education years.

COVID-19 Vaccination Intent and Willingness to Pay in Bangladesh: A Cross-Sectional Study

This article reports the intent to receive a SARS-COV-2 vaccine, its predictors and willingness to pay in Bangladesh. We carried out an online cross-sectional survey of 697 adults from the general population of Bangladesh in January 2021. A structured questionnaire was used to assess vaccination intent. The questionnaire included sociodemographic variables and health belief model constructs which may predict vaccination intent. Among the participants, 26% demonstrated a definite intent, 43% probable intent, 24% probable negative, and 7% a definite negative intention. Multivariable logistic regression analyses suggest an association between definite intent and previous COVID-19 infection (OR: 2.86; 95% CI: 1.71-4.78), perceiving COVID-19 as serious (OR: 1.93; 1.04-3.59), the belief that vaccination would make them feel less worried about catching COVID-19 (OR: 4.42; 2.25-8.68), and concerns about vaccine affordability (OR: 1.51; 1.01-2.25). Individuals afraid of the side effects (OR: 0.34; 0.21-0.53) and those who would take the vaccine if the vaccine were taken by many others (OR: 0.44; 0.29-0.67) are less likely to have a definite intent. A definite negative intent is associated with the concern that the vaccine may not be halal (OR: 2.03; 1.04-3.96). Furthermore, 68.4% are willing to pay for the vaccine. The median amount that they are willing to pay is USD 7.08. The study findings reveal that the definite intent to receive the SARS-CoV-2 vaccination among the general population varies depending on their COVID-19-related health beliefs and no significant association was found with sociodemographic variables.

The Effect of Diclofenac Sodium-Loaded PLGA Rods on Bone Healing and Inflammation: A Histological and Histomorphometric Study in the Femur of Rats

Implants made of poly(lactide-co-glycolide) (PLGA) are biodegradable and frequently provoke foreign body reactions (FBR) in the host tissue. In order to modulate the inflammatory response of the host tissue, PLGA implants can be loaded with anti-inflammatory drugs. The aim of this study was to analyze the impact of PLGA 80/20 rods loaded with the diclofenac sodium (DS) on local tissue reactions in the femur of rats. Special emphasis was put on bone regeneration and the presence of multinucleated giant cells (MGCs) associated with FBR. PLGA 80/20 alone and PLGA 80/20 combined with DS was extruded into rods. PLGA rods loaded with DS (PLGA+DS) were implanted into the femora of 18 rats. Eighteen control rats received unloaded PLGA rods. The follow-up period was of 3, 6 and 12 weeks. Each group comprised of six rats. Peri-implant tissue reactions were histologically and histomorphometrically evaluated. The implantation of PLGA and PLGA+DS8 rods induced the formation of a layer of newly formed bone islands parallel to the contour of the implants. PLGA+DS rods tended to reduce the presence of multi-nucleated giant cells (MGCs) at the implant surface. Although it is known that the systemic administration of DS is associated with compromised bone healing, the local release of DS via PLGA rods did not have negative effects on bone regeneration in the femora of rats throughout 12 weeks.

Desmoglein 3 - Influence on oral carcinoma cell migration and invasion

Desmoglein 3 (Dsg3) is an adhesion receptor in desmosomes, but its role in carcinoma cell migration and invasion is mostly unknown. Our aim was to quantitatively analyse the motion of Dsg3-modified carcinoma cells in 2D settings and in 3D within tumour microenvironment mimicking (TMEM) matrices. We tested mutant constructs of C-terminally truncated Dsg3 (∆238 and ∆560), overexpressed full-length (FL) Dsg3, and empty vector control (Ct) of buccal mucosa squamous cell carcinoma (SqCC/Y1) cells. We captured live cell images and analysed migration velocities and accumulated and Euclidean distances. We compared rodent collagen and Matrigel^® with human Myogel TMEM matrices for these parameters in 3D sandwich, in which we also tested the effects of monoclonal antibody AK23, which targets the EC1 domain of Dsg3. In monolayer culture, FL and both truncated constructs migrated faster and had higher accumulated distances than Ct cells. However, in the 3D assays, only the mutants invaded faster relative to Ct cells. Of the mutants, the shorter form (Δ238) exhibited faster migration and invasion than Δ560 cells. In the Transwell, all of the cells invaded faster through Myogel than Matrigel^® coated wells. In 3D sandwich, AK23 antibody inhibited only the invasion of FL cells. We conclude that different experimental 2D and 3D settings can markedly influence the movement of oral carcinoma cells with various Dsg3 modifications.

Organotypic three-dimensional assays based on human leiomyoma-derived matrices

Alongside cancer cells, tumours exhibit a complex stroma containing a repertoire of cells, matrix molecules and soluble factors that actively crosstalk between each other. Recognition of this multifaceted concept of the tumour microenvironment (TME) calls for authentic TME mimetics to study cancer in vitro. Traditionally, tumourigenesis has been investigated in non-human, three-dimensional rat type I collagen containing organotypic discs or by means of mouse sarcoma-derived gel, such as Matrigel^®. However, the molecular compositions of these simplified assays do not properly simulate human TME. Here, we review the main properties and benefits of using human leiomyoma discs and their matrix Myogel for in vitro assays. Myoma discs are practical for investigating the invasion of cancer cells, as are cocultures of cancer and stromal cells in a stiff, hypoxic TME mimetic. Myoma discs contain soluble factors and matrix molecules commonly present in neoplastic stroma. In Transwell, IncuCyte, spheroid and sandwich assays, cancer cells move faster and form larger colonies in Myogel than in Matrigel^®. Additionally, Myogel can replace Matrigel^® in hanging-drop and tube-formation assays. Myogel also suits three-dimensional drug testing and extracellular vesicle interactions. To conclude, we describe the application of our myoma-derived matrices in 3D in vitro cancer assays.

This article is part of the discussion meeting issue ‘Extracellular vesicles and the tumour microenvironment’.

Desmoglein 3 regulates membrane trafficking of cadherins, an implication in cell-cell adhesion

E-cadherin mediated cell-cell adhesion plays a critical role in epithelial cell polarization and morphogenesis. Our recent studies suggest that the desmosomal cadherin, desmoglein 3 (Dsg3) cross talks with E-cadherin and regulates its adhesive function in differentiating keratinocytes. However, the underlying mechanism remains not fully elucidated. Since E-cadherin trafficking has been recognized to be a central determinant in cell-cell adhesion and homeostasis we hypothesize that Dsg3 may play a role in regulating E-cadherin trafficking and hence the cell-cell adhesion. Here we investigated this hypothesis in cells with loss of Dsg3 function through RNAi mediated Dsg3 knockdown or the stable expression of the truncated mutant Dsg3ΔC. Our results showed that loss of Dsg3 resulted in compromised cell-cell adhesion and reduction of adherens junction and desmosome protein expression as well as the cortical F-actin formation. As a consequence, cells failed to polarize but instead displayed aberrant cell flattening. Furthermore, retardation of E-cadherin internalization and recycling was consistently observed in these cells during the process of calcium induced junction assembling. In contrast, enhanced cadherin endocytosis was detected in cells with overexpression of Dsg3 compared to control cells. Importantly, this altered cadherin trafficking was found to be coincided with the reduced expression and activity of Rab proteins, including Rab5, Rab7 and Rab11 which are known to be involved in E-cadherin trafficking. Taken together, our findings suggest that Dsg3 functions as a key in cell-cell adhesion through at least a mechanism of regulating E-cadherin membrane trafficking.

A novel human leiomyoma tissue derived matrix for cell culture studies

Background

The composition of the matrix molecules is important in in vitro cell culture experiments of e.g. human cancer invasion and vessel formation. Currently, the mouse Engelbreth-Holm-Swarm (EHS) sarcoma -derived products, such as Matrigel®, are the most commonly used tumor microenvironment (TME) mimicking matrices for experimental studies. However, since Matrigel® is non-human in origin, its molecular composition does not accurately simulate human TME. We have previously described a solid 3D organotypic myoma disc invasion assay, which is derived from human uterus benign leiomyoma tumor. Here, we describe the preparation and analyses of a processed, gelatinous leiomyoma matrix, named Myogel.

Methods

A total protein extract, Myogel, was formulated from myoma. The protein contents of Myogel were characterized and its composition and properties compared with a commercial mouse Matrigel®. Myogel was tested and compared to Matrigel® in human cell adhesion, migration, invasion, colony formation, spheroid culture and vessel formation experiments, as well as in a 3D hanging drop video image analysis.

Results

We demonstrated that only 34 % of Myogel’s molecular content was similar to Matrigel®. All test results showed that Myogel was comparable with Matrigel®, and when mixed with low-melting agarose (Myogel-LMA) it was superior to Matrigel® in in vitro Transwell® invasion and capillary formation assays.

Conclusions

In conclusion, we have developed a novel Myogel TME matrix, which is recommended for in vitro human cell culture experiments since it closely mimics the human tumor microenvironment of solid cancers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1944-z) contains supplementary material, which is available to authorized users.