Differentially Expressed microRNAs in MIA PaCa-2 and PANC-1 Pancreas Ductal Adenocarcinoma Cell Lines are Involved in Cancer Stem Cell Regulation

Discovery of novel TANK-Binding Kinase 1 (TBK1) inhibitor against pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has limited treatment options, underscoring the urgent need for developing new therapies. The upregulation of TBK1 activity plays a crucial role in multiple pancreatic cancer-related signaling pathways, suggesting that inhibiting the kinase activity of TBK1 could be a promising strategy. Herein, we discovered a novel TBK1 inhibitor, LIB3S0280, using a structure-based virtual screening (SBVS) strategy. In the anti-proliferative and viability assays, LIB3S0280 showed significant inhibition against pancreatic cancer cell lines that highly express TBK1 with the GI50 values of 2.24 and 4.71 μM and IC50 values of 6.64 and 10.98 μM at 96 h. For the downstream targets, LIB3S0280 can inhibit TBK1 downstream signaling by decreasing the phosphorylation of IκBα and AKT better than a known TBK1 inhibitor, BX-795. Furthermore, PDAC cells were arrested in G2/M and underwent apoptosis or senescence with the treatment of LIB3S0280. These findings suggest that TBK1 inhibitor LIB3S0280 has great potential as a lead compound in the further development of a novel treatment for PDAC.

A highly fluorescent and readily accessible all-organic photosensitizer model for advancing image-guided cancer PDT

The potential of using image-guided photodynamic therapy (ig-PDT) for cancer, especially with highly biocompatible fluorescent agents free of heavy atoms, is well recognized. This is due to key advantages related to minimizing adverse side effects associated with standard cancer chemotherapy. However, this theragnostic approach is strongly limited by the lack of synthetically-accessible and easily-modulable chemical scaffolds, enabling the rapid design and construction of advanced agents for clinical ig-PDT. In fact, there are still very few ig-PDT agents clinically approved. Herein we report a readily accessible, easy-tunable and highly fluorescent all-organic small photosensitizer, as a model design for accelerating the development and translation of advanced ig-PDT agents for cancer. This scaffold is based on BODIPY, which assures high fluorescence, accessibility, and ease of performance adaptation by workable chemistry. The optimal PDT performance of this BODIPY dye, tested in highly resistant pancreatic cancer cells, despite its high fluorescent behavior, maintained even after fixation and cancer cell death, is based on its selective accumulation in mitochondria. This induces apoptosis upon illumination, as evidenced by proteomic studies and flow cytometry. All these characteristics make the reported BODIPY-based fluorescent photosensitizer a valuable model for the rapid development of ig-PDT agents for clinical use.

Tumor Microenvironment Modulates Invadopodia Activity of Non-Selected and Acid-Selected Pancreatic Cancer Cells and Its Sensitivity to Gemcitabine and C18-Gemcitabine

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease with high mortality due to early metastatic dissemination and high chemoresistance. All these factors are favored by its extracellular matrix (ECM)-rich microenvironment, which is also highly hypoxic and acidic. Gemcitabine (GEM) is still the first-line therapy in PDAC. However, it is quickly deaminated to its inactive metabolite. Several GEM prodrugs have emerged to improve its cytotoxicity. Here, we analyzed how the acidic/hypoxic tumor microenvironment (TME) affects the response of PDAC cell death and invadopodia-mediated ECM proteolysis to both GEM and its C18 prodrug.

METHODS

For this, two PDAC cell lines, PANC-1 and Mia PaCa-2 were adapted to pHe 6.6 or not for 1 month, grown as 3D organotypic cultures and exposed to either GEM or C18 in the presence and absence of acidosis and the hypoxia inducer, deferoxamine.

RESULTS

We found that C18 has higher cytotoxic and anti-invadopodia activity than GEM in all culture conditions and especially in acid and hypoxic environments.

CONCLUSIONS

We propose C18 as a more effective approach to conventional GEM in developing new therapeutic strategies overcoming PDAC chemoresistance.

In-vitro model to mimic T cell subset change in human PDAC organoid co-culture

PURPOSE

Immunotherapies have largely failed as treatment options for pancreatic ductal adenocarcinoma (PDAC). In this field, clinical translational studies into personalized treatment are of fundamental importance. In our study, we model tumor-cell immune-cell interactions in a co-culture of primary human PDAC organoids and matched peripheral blood mononuclear cells (PBMCs).

METHODS

Using flow cytometry, we evaluated changes in T cell subtypes upon co-culture of patient-derived PDAC organoids and matched PBMCs.

RESULTS

After co-culturing PDAC organoids with PBMCs, we observed changes in CD4+, CD8+ and Treg cell populations. We observed favorable clinical outcome in patients whose PBMCs reacted to the co-culture with organoids.

CONCLUSION

This experimental model allows to investigate interactions between patient derived PDAC organoids and their PBMCs. This co-culture system could serve as a preclinical platform to guide personalized therapeutic strategies in the future.

Differential miRNA expression of hypoxic MCF7 and PANC-1 cells

Background

Hypoxia plays a critical role in the tumor microenvironment by affecting cellular proliferation, metabolism, apoptosis, DNA repair, and chemoresistance. Since hypoxia provokes a distinct shift of microRNA, it is important to illustrate the relative contribution of each hypoxamiR to cancer progression.

Aims

The present study aims to shed light on the hypoxamiRs that are involved in pancreatic and breast cancer progression to highlight novel targets for the development of new therapies.

Methods

For 20 cycles, MCF7 breast cancer cells and PANC-1 pancreatic cancer cells were subjected to chronic cyclic hypoxia, which consisted of 72 hours of hypoxia followed by 24 hours of reoxygenation. After 10 and 20 cycles of hypoxia, miRNA expression alterations were profiled using RT-PCR array and further analyzed using a visual analytics platform. The MTT cell proliferation assay was used to determine hypoxic cells' chemoresistance to doxorubicin.

Results

Under chronic cyclic hypoxia, hypoxic PANC-1 cells have a comparable doubling time with their normoxic counterparts, whereas hypoxic MCF7 cells show a massive increase in doubling time when compared to their normoxic counterparts. Both hypoxic cell lines developed EMT-like phenotypes as well as doxorubicin resistance. According to the findings of miRNet, 6 and 10 miRNAs were shown to play an important role in enriching six hallmarks of pancreatic cancer in the 10th and 20th cycles of hypoxia, respectively, while 7 and 11 miRNAs were shown to play an important role in enriching the four hallmarks of breast cancer in the 10th and 20th cycles of hypoxia, respectively.

Conclusions

miR-221, miR-21, miR-155, and miR-34 were found to be involved in the potentiation of hypoxic PANC-1 hallmarks at both the 10th and 20th cycles, while miR-93, miR-20a, miR-15, and miR-17 were found to be involved in the potentiation of hypoxic MCF7 hallmarks at both the 10th and 20th cycles. This variation in miRNA expression was also connected to the emergence of an EMT-like phenotype, alterations in proliferation rates, and doxorubicin resistance. The chemosensitivity results revealed that chronic cyclic hypoxia is critical in the formation of chemoresistant phenotypes in pancreatic and breast cancer cells. miR-181a and let-7e expression disparities in PANC1, as well as miR-93, miR-34, and miR-27 expression disparities in MCF7, may be associated with the formation of chemoresistant MCF7 and PANC-1 cells following 20 cycles of chronic cyclic hypoxia. Indeed, further research is needed since the particular mechanisms that govern these processes are unknown.

Anticancer Activity of Sunitinib Analogues in Human Pancreatic Cancer Cell Cultures under Normoxia and Hypoxia

Pancreatic cancer remains one of the deadliest cancer types. It is usually characterized by high resistance to chemotherapy. However, cancer-targeted drugs, such as sunitinib, recently have shown beneficial effects in pancreatic in vitro and in vivo models. Therefore, we chose to study a series of sunitinib derivatives developed by us, that were proven to be promising compounds for cancer treatment. The aim of our research was to evaluate the anticancer activity of sunitinib derivatives in human pancreatic cancer cell lines MIA PaCa-2 and PANC-1 under normoxia and hypoxia. The effect on cell viability was determined by the MTT assay. The compound effect on cell colony formation and growth was established by clonogenic assay and the activity on cell migration was estimated using a ‘wound healing’ assay. Six out of 17 tested compounds at 1 µM after 72 h of incubation reduced cell viability by 90% and were more active than sunitinib. Compounds for more detailed experiments were chosen based on their activity and selectivity towards cancer cells compared to fibroblasts. The most promising compound EMAC4001 was 24 and 35 times more active than sunitinib against MIA PaCa-2 cells, and 36 to 47 times more active against the PANC-1 cell line in normoxia and hypoxia. It also inhibited MIA PaCa-2 and PANC-1 cell colony formation. Four tested compounds inhibited MIA PaCa-2 and PANC-1 cell migration under hypoxia, but none was more active than sunitinib. In conclusion, sunitinib derivatives possess anticancer activity in human pancreatic adenocarcinoma MIA PaCa-2 and PANC-1 cell lines, and they are promising for further research.

Cholesterol Synthesis Is Important for Breast Cancer Cell Tumor Sphere Formation and Invasion

Breast cancer has a high risk of recurrence and distant metastasis after remission. Controlling distant metastasis is important for reducing breast cancer mortality, but accomplishing this goal remains elusive. In this study, we investigated the molecular pathways underlying metastasis using cells that mimic the breast cancer distant metastasis process. HCC1143 breast cancer cells were cultured under two-dimensional (2D)-adherent, tumor sphere (TS), and reattached (ReA) culture conditions to mimic primary tumors, circulating tumor cells, and metastasized tumors, respectively. ReA cells demonstrated increased TS formation and enhanced invasion capacity compared to the original 2D-cultured parental cells. In addition, ReA cells had a higher frequency of ESA⁺CD44⁺CD24⁻ population, which represents a stem-cell-like cell population. RNA sequencing identified the cholesterol synthesis pathway as one of the most significantly increased pathways in TS and ReA cells compared to parental cells, which was verified by measuring intracellular cholesterol levels. Furthermore, the pharmacological inhibition of the cholesterol synthesis pathway decreased the ability of cancer cells to form TSs and invade. Our results suggest that the cholesterol synthesis pathway plays an important role in the distant metastasis of breast cancer cells by augmenting TS formation and invasion capacity.

Overexpression of microRNA-345 Affects the Invasive Capacity of Pancreatic Ductal Adenocarcinoma Cell Lines by Suppressing MUC1 and TJP2 Expression

The majority of pancreatic carcinomas are pancreatic ductal adenocarcinomas (PDAC), and the presence of non-invasive pancreatic intraepithelial neoplasia or intraductal papillary mucinous neoplasm, as an associated lesion, is considered important. These microscopic hyperplastic or grossly papillomatous lesions exhibit varying degrees of morphological atypia and may develop into invasive carcinomas. In this study, we investigated whether mucin-1 (MUC1) is involved in the progression of pancreatic carcinoma and examined the mechanisms by which microRNAs regulate MUC1 expression in vitro. In PDAC cell lines, suppression of MUC1 expression reduced cell proliferation and invasion; PDAC cell lines transfected with an miR-345 precursor suppressed the expression of MUC1, and reduced cell proliferation and invasion. Tight junction protein 2 (TJP2), a putative target of miR-345, is regulated by MUC1. The suppression of TJP2 expression reduced cell proliferation by inducing apoptosis. These results suggest that MUC1 and TJP2, the putative target molecules of miR-345, are critical in maintaining the invasive potential of pancreatic carcinoma cells, and regulating their expression may prevent the progression of non-invasive pancreatic intraductal lesions to invasive carcinomas. This study provides new insights for the development of novel molecular targeted therapies for pancreatic carcinomas.

Morphofunctional analysis of human pancreatic cancer cell lines in 2- and 3-dimensional cultures

Genetic, transcriptional, and morphological differences have been reported in pancreatic ductal adenocarcinoma (PDAC) cases. We recently found that epithelial or mesenchymal features were enhanced in three-dimensional (3D) cultures compared to two-dimensional (2D) cultures. In this study, we examined the differences in the morphological and functional characteristics of eight PDAC cell lines in 2D and 3D cultures. Most PDAC cells showed similar pleomorphic morphologies in 2D culture. Under 3D culture, PDAC cells with high E-cadherin and low vimentin expression levels (epithelial) formed small round spheres encircled with flat lining cells, whereas those with high vimentin and low E-cadherin expression levels (mesenchymal) formed large grape-like spheres without lining cells and were highly proliferative. In 3D culture, gemcitabine was more effective for the spheres formed by PDAC cells with epithelial features, while abraxane was more effective on those with mesenchymal features. The expression levels of drug transporters were highest PDAC cells with high vimentin expression levels. These findings indicate that PDAC cells possess various levels of epithelial and mesenchymal characteristics. The 3D-culture method is useful for investigating the diversity of PDAC cell lines and may play important roles in the development of personalized early diagnostic methods and anticancer drugs for PDAC.

Predicting the bioactivity of 2-alkoxycarbonylallyl esters as potential antiproliferative agents against pancreatic cancer (MiaPaCa-2) cell lines: GFA-based QSAR and ELM-based models with molecular docking

BACKGROUND

The number of cancer-related deaths is on the increase, combating this deadly disease has proved difficult owing to resistance and some serious side effects associated with drugs used to combat it. Therefore, scientists continue to probe into the mechanism of action of cancer cells and designing novel drugs that could combat this disease more safely and effectively. Here, we developed a genetic function approximation model to predict the bioactivity of some 2-alkoxyecarbonyl esters and probed into the mode of interaction of these molecules with an epidermal growth factor receptor (3POZ) using the three-dimensional quantitative structure activity relationship (QSAR), extreme learning machine (ELM), and molecular docking techniques.

RESULTS

The developed QSAR model with predicted (R2pred) of 0.756 showed that the model was fit to be validated parameter for a built model and also proved that the developed model could be used in practical situation, R2 for training set (0.9929) and test set (0.8397) confirmed that the model could successfully predict the activity of new compounds due to its correlation with the experimental activity, the models generated with ELM models showed improved prediction of the activity of the molecules. The lead compounds (22 and 23) had binding energies of -6.327 and -7.232 kcalmol-1 for 22 and 23 respectively and displayed better inhibition at the binding sites of 3POZ when compared with that of the standard drug, chlorambucil (-6.0 kcalmol-1). This could be attributed to the presence of double bonds and the α-ester groups.

CONCLUSION

The QSAR and ELM models had good prognostic ability and could be used to predict the bioactivity of novel anti-proliferative drugs.

Functional expression of the transient receptor potential ankyrin type 1 channel in pancreatic adenocarcinoma cells

The transient receptor potential ankyrin type 1 (TRPA1) channel belongs to the TRP superfamily of ion channels. TRPA1 is a membrane protein with multiple functions able to respond to noxious stimuli, reactive oxygen species, inflammatory cytokines or pungent substances, and it participates in pain signalling, taste, inflammation and various steps of the tumorigenic process. To date, no reports have addressed the expression and function of TRPA1 in pancreatic ductal adenocarcinoma (PDAC) cells. This work reports the endogenous expression of TRPA1 channels in human pancreatic adenocarcinoma cell lines and provides insights into the function of the TRPA1 protein in the Panc-1 cell line. This study reports that cell lines isolated from PDAC patients had different levels of TRPA1 expression. The channel activity in Panc-1 cells, as assessed with electrophysiological (whole-cell patch clamp) and microfluorimetry methods, showed that non-selective cationic currents were activated by allyl isothiocyanate (AITC) in Panc-1 cells and inhibited by the selective TRPA1 antagonist A-967079. The current elicited by the specific agonist was associated with a robust increase in intracellular Ca²⁺. Furthermore, siRNA-induced downregulation of TRPA1 enhanced cell migration in the wound healing assay, indicating a possible role of ion channels independent from pore function. Finally, TRPA1 activation changed the cell cycle progression. Taken together, these results support the idea of channel-dependent and independent role for TRPA1 in tumoral processes.

Preclinical models of pancreatic ductal adenocarcinoma: challenges and opportunities in the era of precision medicine

Pancreatic ductal adenocarcinoma (PDAC) is an extremely lethal malignancy, with an average 5-year survival rate of 9% (Siegel RL, Miller KD, Jemal A. Ca Cancer J Clin. 2019;69(1):7-34). The steady increase in mortality rate indicates limited efficacy of the conventional regimen. The heterogeneity of PDAC calls for personalized treatment in clinical practice, which requires the construction of a preclinical system for generating patient-derived models. Currently, the lack of high-quality preclinical models results in ineffective translation of novel targeted therapeutics. This review summarizes applications of commonly used models, discusses major difficulties in PDAC model construction and provides recommendations for integrating workflows for precision medicine.

Blocking circ_0013912 Suppressed Cell Growth, Migration and Invasion of Pancreatic Ductal Adenocarcinoma Cells in vitro and in vivo Partially Through Sponging miR-7-5p

Background

Circular RNAs have been emerging as biomarkers in diagnosis and prognosis of pancreatic ductal adenocarcinoma (PDAC). The hsa_circ_0013912 (circ_0013912) has been retrieved to be upregulated in PDAC. Here, we further investigated its role in PDAC cells, as well as its mechanism via serving as competing endogenous RNA (ceRNA) for miRNA (miR)-7-5p, which is abundant in pancreas and suppresses the development of PDAC.

Materials and Methods

The clinical human tissues were harvested from Gene Expression Omnibus (GEO) database and PDAC patients, and expression of circ_0013912 and miR-7-5p was detected by real-time quantitative PCR. The interaction between both was confirmed by dual-luciferase reporter assay, RNA immunoprecipitation and biotin-miRNA pull-down assay. Functional experiments were performed using Cell Counting Kit-8 assay, colony formation assay, fluorescence-activated cell separation method, caspase 3 activity assay kit, Western blotting, transwell assays, and xenograft tumor model.

Results

circ_0013912 was upregulated in PDAC tumors and cells; besides, circ_0013912 upregulation was associated with TNM stage and lymph node metastasis. Silencing circ_0013912 inhibited cell viability, colony formation ability, cell cycle entrance, migration and invasion, but facilitated apoptosis rate and caspase 3 activity in PANC-1 and AsPC-1 cells, accompanied with decreased c-myc, cyclin D1 and vimentin, and increased E-cadherin. Furthermore, miR-7-5p was a target of circ_0013912. Blocking miR-7-5p could promote cell growth, migration and invasion of PANC-1 and AsPC-1 cells with circ_0013912 silencing or not. Tumor growth was also restrained by circ_0013912 downregulation.

Conclusion

Circ_0013912 knockdown could suppress cell growth and metastasis of PDAC cells via sponging miR-7-5p.