Nanog-mediated stem cell properties is critical for MBNL3 associated paclitaxel resistance of ovarian cancer

MBNL3 Acts as a Target of miR-302e to Facilitate Cell Proliferation, Invasion and Angiogenesis of Gastric Adenocarcinoma via AKT/VEGFA Pathway

Gastric adenocarcinoma (GAC) is a common, malignant type of tumor in human, and is accompanied with higher mortality. Muscleblind-like 3 (MBNL3) was found to be a pivotal participator in aggravating this cancer's progression. However, the regulatory effects of MBNL3 on GAC development have not been investigated. We therefore sought to study the functions of MBNL3 in GAC progression. In this study, it was demonstrated that MBNL3 exhibited higher expression, and GAC patients with higher MBNL3 expression had poor prognosis. Overexpression of MBNL3 facilitated, and knockdown of MBNL3 suppressed cell proliferation, invasion, and angiogenesis in GAC. Further experiments showed that miR-302e targets MBNL3. Rescue assays then uncovered that the miR-302e/MBNL3 axis aggravated GAC progression. In addition, MBNL3 activated the AKT/VEGFA pathway, and the suppressive regulatory impacts of MBNL3 knockdown on GAC cell proliferation, invasion, and angiogenesis could be rescued after 740 Y-P treatment. Through in vivo assay, it was proved that MBNL3 accelerated tumor growth in vivo. In conclusion, MBNL3 acted as a target of miR-302e to facilitate cell proliferation, invasion, and angiogenesis of gastric adenocarcinoma through the AKT/VEGFA pathway. Our findings illustrate that MBNL3 may be an available bio-target for GAC treatment.

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

TATA-box-binding protein promotes hepatocellular carcinoma metastasis through epithelial-mesenchymal transition

BACKGROUND

HCC characterizes malignant metastasis with high incidence and recurrence. Thus, it is pivotal to discover the mechanisms of HCC metastasis. TATA-box-binding protein (TBP), a general transcriptional factor (TF), couples with activators and chromatin remodelers to sustain the transcriptional activity of target genes. Here, we investigate the key role of TBP in HCC metastasis.

METHODS

TBP expression was measured by PCR, western blot, and immunohistochemistry. RNA-sequencing was performed to identify downstream proteins. Functional assays of TBP and downstream targets were identified in HCC cell lines and xenograft models. Luciferase reporter and chromatin immunoprecipitation assays were used to demonstrate the mechanism mediated by TBP.

RESULTS

HCC patients showed high expression of TBP, which correlated with poor prognosis. Upregulation of TBP increased HCC metastasis in vivo and in vitro, and muscleblind-like-3 (MBNL3) was the effective factor of TBP, positively related to TBP expression. Mechanically, TBP transactivated and enhanced MBNL3 expression to stimulate exon inclusion of lncRNA-paxillin (PXN)-alternative splicing (AS1) and, thus, activated epithelial-mesenchymal transition for HCC progression through upregulation of PXN.

CONCLUSIONS

Our data revealed that TBP upregulation is an HCC enhancer mechanism that increases PXN expression to drive epithelial-mesenchymal transition.

Self-transfecting GMO-PMO chimera targeting Nanog enable gene silencing in vitro and suppresses tumor growth in 4T1 allografts in mouse

Phosphorodiamidate morpholino oligonucleotide (PMO)-based antisense reagents cannot enter cells without the help of a delivery technique, which limits their clinical applications. To overcome this problem, self-transfecting guanidinium-linked morpholino (GMO)-PMO or PMO-GMO chimeras have been explored as antisense agents. GMO facilitates cellular internalization and participates in Watson-Crick base pairing. Targeting NANOG in MCF7 cells resulted in decline of the whole epithelial to mesenchymal transition (EMT) and stemness pathway, evident through its phenotypic manifestations, all of which were promulgated in combination with Taxol due to downregulation of MDR1 and ABCG2. GMO-PMO-mediated knockdown of no tail gene resulted in desired phenotypes in zebrafish even upon delivery after 16-cell stages. In BALB/c mice, 4T1 allografts were found to regress via intra-tumoral administration of NANOG GMO-PMO antisense oligonucleotides (ASOs), which was associated with occurrence of necrotic regions. GMO-PMO-mediated tumor regression restored histopathological damage in liver, kidney, and spleen caused by 4T1 mammary carcinoma. Serum parameters of systemic toxicity indicated that GMO-PMO chimeras are safe. To the best of our knowledge, self-transfecting antisense reagent is the first report since the discovery of guanidinium-linked DNA (DNG), which could be useful as a combination cancer therapy and, in principle, can render inhibition of any target gene without using any delivery vehicle.

Targeting CD44-positive ovarian cancers via engineered paclitaxel prodrug nanoparticles for enhanced chemotherapeutic efficacy

Ovarian cancer (OvCa) is currently the fifth most lethal malignancy affecting women health owing to the lack of early diagnosis and treatment choices available before the disease has progressed to a later stage. Paclitaxel (PTX) has shown substantial antineoplastic action against a variety of human cancers, including OvCa, for multiple decades. Despite this, the therapeutic use of this drug is not yet adequate owing to surfactant-related toxicities and off-target effects. In response to these constraints, nanoparticle carriers have evolved as delivery tools for the biocompatible and target delivery of PTX. In this work, a novel polymeric PTX formulation was developed for targeted therapy of OvCa cells, which was achieved by prodrug engineering and HA decoration strategies. Further studies indicated that HA-coated nanodrugs (HA-PLA-PTX NPs) could preferentially accumulate in the CD44-expressing SKOV3 cells, which induced elevated cytotoxicity, reduced cell proliferation, and increased cell apoptosis. In vivo study also demonstrated that equivalent doses of HA-PLA-PTX NPs surpassed the clinical PTX formulation Taxol in a SKOV3 xenograft tumor model. In conclusion, HA-PLA-PTX NPs might be a potentially feasible delivery system for effective OvCa treatment.

The IVF-generated human embryonic microenvironment reverses progestin resistance in endometrial cancer cells by inducing cancer stem cell differentiation

Progestin resistance is a critical factor that prevents patients with endometrial cancer (EC) from receiving conservative therapy. However, the etiology remains elusive. Cancer stem cells (CSCs) may be a contributing factor to progestin resistance in EC. These cells share similar stemness properties with embryonic stem cells that have a multipotent but differential naïve phenotype. Embryonic stem cells are programed to self-renew, to differentiate and to show plasticity toward a normal cellular phenotype in their defined microenvironment. However, whether this microenvironment may promote CSC differentiation toward a better responsive phenotype and reverse progestin resistance has not yet been clarified. In the current study, we found that progestin resistance of endometrial CSCs can be improved or reversed by using in vitro fertilization (IVF)-generated embryonic sac-derived fluid containing the embryonic microenvironment. Furthermore, suppression or reversal of progestin resistance was mediated by placental alkaline phosphatase (ALPP), a factor secreted into the embryonic microenvironment by IVF-generated blastocysts. ALPP significantly reversed progestin resistance by facilitating endometrial CSC differentiation through downregulating the stemness genes NANOG, OCT4 and SOX2. We further showed that the downregulation of NANOG, OCT4 and SOX2 by ALPP was carried out by TET1/2-mediated epigenetic modulation of the promoter regions of these genes. Such changes at the molecular level initiated endometrial CSC differentiation and promoted a better responsive endometrial cancer phenotype. In fact, their response to progestin treatment was similar to that of well-differentiated endometrioid carcinoma cells without CSCs. ALPP could be a novel target in the process to overcome progestin resistance, and such findings may provide a new approach for the conservative treatment of endometrial cancer.