Annexin A2 contributes to cisplatin resistance by activation of JNK-p53 pathway in non-small cell lung cancer cells

Promoter Hypomethylation Upregulates ANXA2 Expression in Pancreatic Cancer and is Associated with Poor Prognosis

Pancreatic cancer (PC) is one of the world's most aggressive and deadly cancers, owing to non-specific early clinical symptoms, late-stage diagnosis, and poor survival. Therefore, it is critical to identify specific biomarkers for its early diagnosis. Annexin A2 (ANXA2) is a calcium-dependent phospholipid-binding protein that has been reported to be upregulated in several cancer types, making it an emerging biomarker and potential cancer therapeutic target. However, the mechanism underlying the regulation of ANXA2 overexpression is still unclear. It is well established that genetic and epigenetic alterations may lead to widespread dysregulation of gene expression. Hence, in this study, we focused on exploring the regulatory mechanism of ANXA2 by investigating the transcriptional profile, methylation pattern, somatic mutation, and prognostic value of ANXA2 in PC using several bioinformatics databases. Our results revealed that the expression levels of ANXA2 were remarkably increased in PC tissues comparing to normal tissues. Furthermore, the high expression of ANXA2 was significantly related to the poor prognosis of PC patients. More importantly, we demonstrated for the first time that the ANXA2 promoter is hypomethylated in PC tissues compared to normal tissues which may result in ANXA2 overexpression in PC. However, more experimental research is required to corroborate our findings.

Annexin A2: A Double-Edged Sword in Pathogen Infection

Annexin A2 (ANXA2) is a multifunctional calcium- and phospholipid-binding protein that plays an important role in various cells. During pathogen infections, ANXA2 modulates the nuclear factor kappa-B (NF-κB) and cell apoptosis signaling pathways and guides the chemotaxis of inflammatory cells toward inflammation sites, thereby protecting the host organism through the modulation of the inflammatory response. In addition, ANXA2 can regulate immune responses, and in certain pathogen infections, it can interact with pathogen proteins to facilitate their invasion and proliferation. This review provides an overview of the research progress on how ANXA2 regulates pathogen infections.

SPG21, a potential oncogene targeted by miR-128-3p, amplifies HBx-induced carcinogenesis and chemoresistance via activation of TRPM7-mediated JNK pathway in hepatocellular carcinoma

PURPOSE

Chronic hepatitis B virus (HBV) infection is the primary risk factor for the malignant progression of hepatocellular carcinoma (HCC). It has been reported that HBV X protein (HBx) possesses oncogenic properties, promoting hepatocarcinogenesis and chemoresistance. However, the detailed molecular mechanisms are not fully understood. Here, we aim to investigate the effects of miR-128-3p/SPG21 axis on HBx-induced hepatocarcinogenesis and chemoresistance.

METHODS

The expression of SPG21 in HCC was determined using bioinformatics analysis, quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry (IHC). The roles of SPG21 in HCC were elucidated through a series of in vitro and in vivo experiments, including real-time cellular analysis (RTCA), matrigel invasion assay, and xenograft mouse model. Pharmacologic treatment and flow cytometry were performed to demonstrate the potential mechanism of SPG21 in HCC.

RESULTS

SPG21 expression was elevated in HCC tissues compared to adjacent non-tumor tissues (NTs). Moreover, higher SPG21 expression correlated with poor overall survival. Functional assays revealed that SPG21 fostered HCC tumorigenesis and invasion. MiR-128-3p, which targeted SPG21, was downregulated in HCC tissues. Subsequent analyses showed that HBx amplified TRPM7-mediated calcium influx via miR-128-3p/SPG21, thereby activating the c-Jun N-terminal kinase (JNK) pathway. Furthermore, HBx inhibited doxorubicin-induced apoptosis by engaging the JNK pathway through miR-128-3p/SPG21.

CONCLUSION

The study suggested that SPG21, targeted by miR-128-3p, might be involved in enhancing HBx-induced carcinogenesis and doxorubicin resistance in HCC via the TRPM7/Ca2+/JNK signaling pathway. This insight suggested that SPG21 could be recognized as a potential oncogene, offering a novel perspective on its role as a prognostic factor and a therapeutic target in the context of HCC.

Streptococcus anginosus promotes gastric inflammation, atrophy, and tumorigenesis in mice

Streptococcus anginosus (S. anginosus) was enriched in the gastric mucosa of patients with gastric cancer (GC). Here, we show that S. anginosus colonized the mouse stomach and induced acute gastritis. S. anginosus infection spontaneously induced progressive chronic gastritis, parietal cell atrophy, mucinous metaplasia, and dysplasia in conventional mice, and the findings were confirmed in germ-free mice. In addition, S. anginosus accelerated GC progression in carcinogen-induced gastric tumorigenesis and YTN16 GC cell allografts. Consistently, S. anginosus disrupted gastric barrier function, promoted cell proliferation, and inhibited apoptosis. Mechanistically, we identified an S. anginosus surface protein, TMPC, that interacts with Annexin A2 (ANXA2) receptor on gastric epithelial cells. Interaction of TMPC with ANXA2 mediated attachment and colonization of S. anginosus and induced mitogen-activated protein kinase (MAPK) activation. ANXA2 knockout abrogated the induction of MAPK by S. anginosus. Thus, this study reveals S. anginosus as a pathogen that promotes gastric tumorigenesis via direct interactions with gastric epithelial cells in the TMPC-ANXA2-MAPK axis.

Targeting PAK4 reverses cisplatin resistance in NSCLC by modulating ER stress

Chemoresistance poses a significant impediment to effective treatments for non-small-cell lung cancer (NSCLC). P21-activated kinase 4 (PAK4) has been implicated in NSCLC progression by invasion and migration. However, the involvement of PAK4 in cisplatin resistance is not clear. Here, we presented a comprehensive investigation into the involvement of PAK4 in cisplatin resistance within NSCLC. Our study revealed enhanced PAK4 expression in both cisplatin-resistant NSCLC tumors and cell lines. Notably, PAK4 silencing led to a remarkable enhancement in the chemosensitivity of cisplatin-resistant NSCLC cells. Cisplatin evoked endoplasmic reticulum stress in NSCLC. Furthermore, inhibition of PAK4 demonstrated the potential to sensitize resistant tumor cells through modulating endoplasmic reticulum stress. Mechanistically, we unveiled that the suppression of the MEK1-GRP78 signaling pathway results in the sensitization of NSCLC cells to cisplatin after PAK4 knockdown. Our findings establish PAK4 as a promising therapeutic target for addressing chemoresistance in NSCLC, potentially opening new avenues for enhancing treatment efficacy and patient outcomes.

Prognostic significance of annexin A2 and tumor associated macrophages (TAMs) in metastatic renal cell carcinoma and their relation to Sunitinib resistance

Sunitinib, an antiangiogenic tyrosine kinase inhibitor, is the main treatment for metastatic renal cell carcinoma (mRCC). Development of resistance is a major obstacle against therapy success. The aim of this study was to assess annexin A2 and CD163+ tumor associated macrophages (TAMs) immunohistochemical expression in 50 mRCC cases as regard to patients' prognosis and Sunitinib response. Also, to assess the correlation between annexin A2 and TAMs expression. High annexin A2 expression and TAMs density were associated with serum calcium level (P = 0.024 and 0.037, respectively), larger tumor size (P < 0.001), high tumor grade (P = 0.014 and <0.001, respectively), and the presence of tumor necrosis (P < 0.001). High annexin A2 and TAMs expressions were related to shorter patients' overall survival (P = 0.009 and 0.001, respectively) and progression-free survival (P = 0.003 and 0.001, respectively). Annexin A2 was correlated with TAMs density (r = 0.890). Annexin A2 and TAMs are associated with poor prognostic parameters in mRCC patients, including high nuclear grade, increased tumor size, and the presence of tumor necrosis, together with shorter patients' survivals and poor response to Sunitinib. Annexin A2 expression is correlated with TAMs density suggesting immunomodulatory role of annexin A2.

Accumulation of annexin A2 and S100A10 prevents apoptosis of apically delaminated, transformed epithelial cells

In various epithelial tissues, the epithelial monolayer acts as a barrier. To fulfill its function, the structural integrity of the epithelium is tightly controlled. When normal epithelial cells detach from the basal substratum and delaminate into the apical lumen, the apically extruded cells undergo apoptosis, which is termed anoikis. In contrast, transformed cells often become resistant to anoikis and able to survive and grow in the apical luminal space, leading to the formation of multilayered structures, which can be observed at the early stage of carcinogenesis. However, the underlying molecular mechanisms still remain elusive. In this study, we first demonstrate that S100A10 and ANXA2 (Annexin A2) accumulate in apically extruded, transformed cells in both various cell culture systems and murine epithelial tissues in vivo. ANXA2 acts upstream of S100A10 accumulation. Knockdown of ANXA2 promotes apoptosis of apically extruded RasV12-transformed cells and suppresses the formation of multilayered epithelia. In addition, the intracellular reactive oxygen species (ROS) are elevated in apically extruded RasV12 cells. Treatment with ROS scavenger Trolox reduces the occurrence of apoptosis of apically extruded ANXA2-knockdown RasV12 cells and restores the formation of multilayered epithelia. Furthermore, ROS-mediated p38MAPK activation is observed in apically delaminated RasV12 cells, and ANXA2 knockdown further enhances the p38MAPK activity. Moreover, the p38MAPK inhibitor promotes the formation of multilayered epithelia of ANXA2-knockdown RasV12 cells. These results indicate that accumulated ANXA2 diminishes the ROS-mediated p38MAPK activation in apically extruded transformed cells, thereby blocking the induction of apoptosis. Hence, ANXA2 can be a potential therapeutic target to prevent multilayered, precancerous lesions.

ANXA2 and Rac1 negatively regulates autophagy and osteogenic differentiation in osteosarcoma cells to confer CDDP resistance

BACKGROUND

Cisplatin (CDDP) is a mainstay chemotherapeutic agent for OS treatment, but drug resistance has become a hurdle to limit its clinical effect. Autophagy plays an important role in CDDP resistance in OS, and in the present study we explored the role of ANXA2 and Rac1 in dictating CDDP sensitivity in OS cells.

METHODS

ANXA2 and Rac1 expression levels were examined by Western blot and autophagy induction was detected by transmission electron miscroscope (TEM) in the clinical samples and OS cell lines. CDDP resistant cells were established by exposing OS cells to increasing doses of CDDP. The effects of ANXA2 and Rac1 knockdown on CDDP sensitivity were evaluated in the cell and animal models.

RESULTS

Reduced autophagy was associated with the increased expression of ANXA2 and Rac1 in CDDP resistant OS tumor samples and cells. Autophagy suppression promoted CDDP resistance and inducing autophagy re-sensitized the resistant cells to CDDP treatment in vitro and in vivo. Further, knocking down ANXA2 or Rac1 re-activated autophagy and attenuated CDDP resistance in OS cells. We further demonstrated that CDDP resistant OS cells displayed a poorer osteogenic differentiation state when compared to the parental cell lines, which was significantly reversed by autophagy re-activation and ANXA2 or Rac1 silencing.

CONCLUSION

Our findings revealed a complicated interplay of ANXA2/Rac1, autophagy induction, and osteogenic differentiation in dictating CDDP resistance in OS cells, suggesting ANXA2 and Rac1 as promising targets to modulate autophagy and overcome CDDP resistance in OS cells.

Analysis of differential membrane proteins related to matrix stiffness-mediated metformin resistance in hepatocellular carcinoma cells

BACKGROUND

Our previous work shows that increased matrix stiffness not only alters malignant characteristics of hepatocellular carcinoma (HCC) cells, but also attenuates metformin efficacy in treating HCC cells. Here, we identified differential membrane proteins related to matrix stiffness-mediated metformin resistance for better understand therapeutic resistance of metformin in HCC.

METHODS

Differential membrane proteins in HCC cells grown on different stiffness substrates before and after metformin intervention were screened and identified using isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with the liquid chromatography-tandem mass spectrometry (LC-MS/MS), then bioinformatic analysis were applied to determine candidate membrane protein and their possible signaling pathway.

RESULTS

A total of 5159 proteins were identified and 354 differential membrane proteins and membrane associated proteins, which might be associated with matrix stiffness-mediated metformin resistance were discovered. Then 94 candidate membrane proteins including 21 up-regulated protein molecules and 73 down-regulated protein molecules were further obtained. Some of them such as Annexin A2 (ANXA2), Filamin-A (FLNA), Moesin (MSN), Myosin-9 (MYH9), Elongation factor 2 (eEF2), and Tax1 binding Protein 3 (TAX1BP3) were selected for further validation. Their expressions were all downregulated in HCC cells grown on different stiffness substrates after metformin intervention. More importantly, the degree of decrease was obviously weakened on the higher stiffness substrate compared with that on the lower stiffness substrate, indicating that these candidate membrane proteins might contribute to matrix stiffness-mediated metformin resistance in HCC.

CONCLUSIONS

There was an obvious change in membrane proteins in matrix stiffness-mediated metformin resistance in HCC cells. Six candidate membrane proteins may reflect the response of HCC cells under high stiffness stimulation to metformin intervention, which deserve to be investigated in the future.

Interactions and conformational changes of annexin A2/p11 heterotetramer models on a membrane: a molecular dynamics study

Ca2+-dependent membrane-binding by the Annexin A2/p11 heterotetramer (A2t) plays an important role in various biological processes including fibrinogen activation and exocytosis in neuroendocrine cells. Two models where A2t associates with a single membrane surface were generated and used to perform molecular dynamics simulations. The first model mimics initial A2t-membrane binding through both Annexin A2 (A2) subunits of A2t (TS model) while the second model mimics A2t-binding through a single A2 subunit (OS model). Conformational changes were summarized using principal component analysis (PCA), simulation snapshots, and distance plots from the simulations. The full TS model, including the p11 dimer, fully associates with the membrane adopting a stable structure with little conformational variation as evidence by PCA. The unassociated subunits of the OS model moved toward the membrane. The molecular mechanics/Generalized-Born surface area (MMGBSA) method was applied to investigate the energetics of the models. The MMGBSA results demonstrated that R63 of p11 was the primary contributor to the p11-membrane interaction. The TS model results were both consistent with those found in the literature and provide novel insights about the specific residues driving the A2t-membrane interaction. Additionally, it represents the most complete model of A2t on the membrane surface available.Communicated by Ramaswamy H. Sarma.

Cell Entry of Avian Reovirus Modulated by Cell-Surface Annexin A2 and Adhesion G Protein-Coupled Receptor Latrophilin-2 Triggers Src and p38 MAPK Signaling Enhancing Caveolin-1- and Dynamin 2-Dependent Endocytosis

The specifics of cell receptor-modulated avian reovirus (ARV) entry remain unknown. By using a viral overlay protein-binding assay (VOPBA) and an in-gel digestion coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS), we determined that cell-surface annexin A2 (AnxA2) and adhesion G protein-coupled receptor Latrophilin-2 (ADGRL2) modulate ARV entry. Direct interaction between the ARV σC protein and AnxA2 and ADGRL2 in Vero and DF-1 cells was demonstrated in situ by proximity ligation assays. By using short hairpin RNAs (shRNAs) to silence the endogenous AnxA2 and ADGRL2 genes, ARV entry could be efficiently blocked. A significant decrease in virus yields and the intracellular specific signal for σC protein was observed in Vero cells preincubated with the specific AnxA2 and ADGRL2 monoclonal antibodies, indicating that AnxA2 and ADGRL2 are involved in modulating ARV entry. Furthermore, we found that cells pretreated with the AnxA2/S100A10 heterotetramer (A2t) inhibitor A2ti-1 suppressed ARV-mediated activation of Src and p38 mitogen-activated protein kinase (MAPK), demonstrating that Src and p38 MAPK serve as downstream molecules of cell-surface AnxA2 signaling. Our results reveal that suppression of cell-surface AnxA2 with the A2ti-1 inhibitor increased Csk-Cbp interaction, suggesting that ARV entry suppresses Cbp-mediated relocation of Csk to the membrane, thereby activating Src. Furthermore, reciprocal coimmunoprecipitation assays revealed that σC can interact with signaling molecules, lipid raft, and vimentin. The current study provides novel insights into cell-surface AnxA2- and ADGRL2-modulated cell entry of ARV which triggers Src and p38 MAPK signaling to enhance caveolin-1-, dynamin 2-, and lipid raft-dependent endocytosis. IMPORTANCE By analyzing results from VOPBA and LC-MS/MS, we have determined that cell-surface AnxA2 and ADGRL2 modulate ARV entry. After ARV binding to receptors, Src and p38 MAPK signaling were triggered and, in turn, increased the phosphorylation of caveolin-1 (Tyr14) and upregulated dynamin 2 expression to facilitate caveolin-1-mediated and dynamin 2-dependent endocytosis. In this work, we demonstrated that ARV triggers Src activation by impeding Cbp-mediated relocation of Csk to the membrane in the early stages of the life cycle. This work provides better insight into cell-surface AnxA2 and ADGRL2, which upregulate Src and p38MAPK signaling pathways to enhance ARV entry and productive infection.

RASSF1A inhibits epithelial-mesenchymal transition of gastric cancer cells by downregulating P-JNK

Gastric cancer (GC) is one of the most common gastrointestinal tumors. In this study, we assessed the biological role of Ras association domain family 1 isoform A (RASSF1A) in GC cells. Expressions of RASSF1A and the relationship of RASSF1A with epithelial-mesenchymal transformation (EMT)-related proteins were assessed in five cell lines using Western blot. GC cells with RASSF1A overexpression were used to study sensitivity to cisplatin, migration, invasion, and the expression of EMT-associated biomarkers. GC cells showed profound downregulation of RASSF1A expression compared with normal human gastric mucosal cells. High RASSF1A expression was associated with increased overall survival. Overexpression of RASSF1A regulates GC cells activity and the expression of EMT-associated biomarkers. RASSF1A regulates E-cadherin and Vimentin through P-JNK pathway. Our results revealed that RASSF1A can inhibit the proliferation, migration, and invasion of GC cells via E-cadherin. Our study provides insights for further research on GC.

In Vitro Anticancer Activity of Novel Ciprofloxacin Mannich Base in Lung Adenocarcinoma and High-Grade Serous Ovarian Cancer Cell Lines via Attenuating MAPK Signaling Pathway

Novel drugs are desperately needed in order to combat a significant challenge due to chemo-therapeutic resistance and bad prognosis. This research aimed to assess the anticancer activity of a newly synthesized ciprofloxacin Mannich base (CMB) on ovarian cancer (OVCAR-3) and lung cancer (A-549) cell lines and to investigate probable involved molecular mechanisms. The cytotoxic and pro-apoptotic impact of CMB on both cell lines was investigated using MTT assay, Annexin V assay, and cell cycle analysis, as well as caspase-3 activation. Western blotting was carried out to evaluate downstream targets of the MAPK pathway, while qRT PCR was used to evaluate the gene expression pattern of the p53/Bax/Bcl2 pathway. CMB treatment showed significantly reduced cell proliferation in both OVCAR-3 and A-549 cells with half maximum inhibitory concentration (IC₅₀) = 11.60 and 16.22 µg/mL, respectively. CMB also induced apoptosis, S phase cell cycle arrest, and up-regulated expression of p53, p21, and Bax while down-regulated Bcl2 expression. CMB also halted cell proliferation by deactivating the MAPK pathway. In conclusion, CMB may be regarded as a potential antiproliferative agent for lung and ovarian cancers due to anti-proliferative and pro-apoptotic actions via inhibition of the MAPK pathway and p53/Bax/Bcl2.

Prognostic role of annexin A2 and cancer-associated fibroblasts in advanced non-small cell lung cancer: Implication in epithelial-mesenchymal transition and gefitinib resistance

BACKGROUND

Despite advances in treatment of non-small cell lung cancer (NSCLC), its prognosis remains dismal. Development of drug resistance is a major obstacle against success of targeted epidermal growth factor receptor (EGFR) -tyrosine kinase inhibitors (TKI) therapy. This study aimed to assess the prognostic role of annexin A2 (ANXA2) expression, within both tumor cells and stroma, as well as cancer associated fibroblasts (CAFs) in NSCLC and to investigate their potential role in induction of epithelial mesenchymal transition (EMT) and resistance to gefitinib.

METHOD

Immunohistochemistry was performed to evaluate tumoral and stromal ANXA2 expression and α-SMA-stained CAFs in 110 advanced NSCLC patients. Furthermore, STAT3 and E-cadherin mRNA expression was studied by quantitative reverse transcription PCR (qRT-PCR).

RESULTS

Both tumoral and stromal ANXA2 as well as CAFs were significantly related to clinical stage IV and malignant pleural effusion, while tumoral ANXA2 was significantly related to poor tumor differentiation. EGFR mutation and high tumoral ANXA2 were independent factors for poor overall survival, whereas high stromal and tumoral ANXA2 and high CAFs were independent predictors for poor progression-free survival. Moreover, high ANXA2 and CAFs were significantly associated with high STAT3 and low E-cadherin mRNA expression. Focusing on EGFR mutated cases, gefitinib resistance was significantly associated with high tumoral and stromal ANXA2, high CAFs, high STAT3 and low E-cadherin.

CONCLUSION

CAFs and ANXA2 could be considered as poor prognostic parameters in advanced NSCLC and are potential factors for gefitinib therapy resistance through EMT induction.

Urinary Exosomal Tissue TIMP and Angiopoietin-1 Are Preoperative Novel Biomarkers of Well-Differentiated Thyroid Cancer

Finding non-invasive and sensitive biomarkers for early screening of high-risk patients remains important in clinical practice. A higher concentration of urine exosomal thyroglobulin protein was found in late-stage patients with thyroid carcinoma compared to those with early stage in our previous study. This prospective study aims to find new prognostic biomarkers before surgery for decision-making with this platform. We enrolled patients newly diagnosed with papillary and follicular cancer from 2017 to 2018. Preoperative urine samples were collected and the exosomal proteins were analyzed. The association of the concentration of urine exosomal proteins with lymph node metastasis and MACIS score (metastasis, age, completeness of resection, invasion, and size) was analyzed with multiple logistic regression. In total, 21 patients were included, with a mean age of 51.29 ± 10.29 years and a majority of female patients (85.71%). The concentration of urine exosomal TIMP (tissue inhibitor of metalloproteinase) was significantly higher in patients with lymph node metastasis (p = 0.01). Multiple logistic regression analysis showed association of urine exosomal TIMP (adjusted odds ratio (aOR): 3.09, 95% confidence interval (CI): 0.99-9.6, p = 0.052), angiopoietin-1 (aOR: 2.24, 95% CI: 0.97-5.15, p = 0.058) with lymph node metastasis. However, no association was noted between MACIS score and various urine exosomal protein candidates. Preoperative urine exosomal data could suggest certain peptides having the potential as prognostic indicators for screening patients with high-risk before surgery. Further study with a large cohort and long follow-up is needed to identify the application of urine exosomal proteins on prognostic prediction.

Synthetic antibody-derived immunopeptide provides neuroprotection in glaucoma through molecular interaction with retinal protein histone H3.1

Glaucoma is a group of optic neuropathies characterized by the progressive degeneration of retinal ganglion cells (RGCs) as well as their axons leading to irreversible loss of sight. Medical management of the intraocular pressure (IOP) still represents the gold standard in glaucoma therapy, which only manages a single risk factor and does not directly address the neurodegenerative component of this eye disease. Recently, our group showed that antibody-derived immunopeptides (encoding complementarity-determining regions, CDRs) provide attractive glaucoma medication candidates and directly interfere its pathogenic mechanisms by different modes of action. In accordance with these findings, the present study showed the synthetic complementary-determining region 2 (CDR2) peptide (INSDGSSTSYADSVK) significantly increased RGC viability in vitro in a concentration-dependent manner (p < 0.05 using a CDR2 concentration of 50 μg/mL). Employing state-of the-art immunoprecipitation experiments, we confirmed that synthetic CDR2 exhibited a high affinity toward the retinal target protein histone H3.1 (HIST1H3A) (p < 0.001 and log2-fold change > 3). Furthermore, molecular dynamics (MD) simulations along with virtual docking analyses predicted potential CDR2-specific binding regions of HIST1H3A, which might represent essential post-translational modification (PTM) sites for epigenetic regulations. Quantitative mass spectrometry (MS) analysis of retinas demonstrated 39 proteins significantly affected by CDR2 treatment (p < 0.05). An up-regulation of proteins involved in the energy production (e.g., ATP5F1B and MT-CO2) as well as the regulatory ubiquitin proteasome system (e.g., PSMC5) was induced by the synthetic CDR2 peptide. On the other hand, CDR2 reduced metabolic key enzymes (e.g., DDAH1 and MAOB) as well as ER stress-related proteins (e.g., SEC22B and VCP) and these data were partially confirmed by microarray technology. Our outcome measurements indicate that specific protein-peptide interactions influence the regulatory epigenetic function of HIST1H3A promoting the neuroprotective mechanism on RGCs in vitro. In addition to IOP management, such synthetic peptides as CDR2 might serve as a synergistic immunotherapy for glaucoma in the future.

Pathobiological functions and clinical implications of annexin dysregulation in human cancers

Annexins are an extensive superfamily of structurally related calcium- and phospholipid-binding proteins, largely conserved and widely distributed among species. Twelve human annexins have been identified, referred to as Annexin A1-13 (A12 remains as of yet unassigned), whose genes are spread throughout the genome on eight different chromosomes. According to their distinct tissue distribution and subcellular localization, annexins have been functionally implicated in a variety of biological processes relevant to both physiological and pathological conditions. Dysregulation of annexin expression patterns and functions has been revealed as a common feature in multiple cancers, thereby emerging as potential biomarkers and molecular targets for clinical application. Nevertheless, translation of this knowledge to the clinic requires in-depth functional and mechanistic characterization of dysregulated annexins for each individual cancer type, since each protein exhibits varying expression levels and phenotypic specificity depending on the tumor types. This review specifically and thoroughly examines the current knowledge on annexin dysfunctions in carcinogenesis. Hence, available data on expression levels, mechanism of action and pathophysiological effects of Annexin A1-13 among different cancers will be dissected, also further discussing future perspectives for potential applications as biomarkers for early diagnosis, prognosis and molecular-targeted therapies. Special attention is devoted to head and neck cancers (HNC), a complex and heterogeneous group of aggressive malignancies, often lately diagnosed, with high mortality, and scarce therapeutic options.

Transcriptome-Wide Analysis of RNA N6-Methyladenosine Modification in Adriamycin-Resistant Acute Myeloid Leukemia Cells

Acute myeloid leukemia (AML) is one of the most aggressive hematopoietic malignancies. Patients still suffer from refractory/relapsed disease after anthracycline-based therapy, which leads to a poor prognosis. N⁶-Methyladenosine (m⁶A) is the most abundant post-transcriptional modification in eukaryotes, the imbalance of which is reported to be associated with various pathological processes, including drug resistance. However, the relationship between m⁶A modification and drug resistance has not been well defined in AML. In this study, we analyzed the sequencing data of HL60 and its Adriamycin-resistant cell line HL60/ADR. We found a total of 40,550 m⁶A-methylated peaks, representing 15,640 genes in HL60, and 38,834 m⁶A-methylated peaks, representing 15,285 genes in HL60/ADR. KEGG pathway analysis showed that pathways were enriched in the FoxO signaling pathway, p53 signaling pathway, and Notch signaling pathway. MeRIP-seq results showed that the fold enrichment of the global m⁶A level in HL60/ADR was higher than that in HL60, and dot blot assay results indicated that the global m⁶A level was elevated in HL60/ADR cells compared with that in HL60 cells. Further analysis revealed that the expression level of METTL3 was elevated in HL60/ADR cells compared with that in HL60 cells. After a combined treatment of STM2457 (an inhibitor of METTL3) and Adriamycin, the proliferation of HL60/ADR was inhibited. Thus, we hypothesized that the abnormality of m⁶A modification played an important role in Adriamycin-resistant AML.

Annexin A2: The Diversity of Pathological Effects in Tumorigenesis and Immune Response

Annexin A2 (ANXA2) is widely used as a marker in a variety of tumors. By regulating multiple signal pathways, ANXA2 promotes the epithelial-mesenchymal transition, which can cause tumorigenesis and accelerate thymus degeneration. The elevated ANXA2 heterotetramer facilitates the production of plasmin, which participates in pathophysiologic processes such as tumor cell invasion and metastasis, bleeding diseases, angiogenesis, inducing the expression of inflammatory factors. In addition, the ANXA2 on the cell membrane mediates immune response via its interaction with surface proteins of pathogens, C1q, toll-like receptor 2, anti-dsDNA antibodies and immunoglobulins. Nuclear ANXA2 plays a role as part of a primer recognition protein complex that enhances DNA synthesis and cells proliferation by acting on the G1-S phase of the cell. ANXA2 reduction leads to the inhibition of invasion and metastasis in multiple tumor cells, bleeding complications in acute promyelocytic leukemia, retinal angiogenesis, autoimmunity response and tumor drug resistance. In this review, we provide an update on the pathological effects of ANXA2 in both tumorigenesis and the immune response. We highlight ANXA2 as a critical protein in numerous malignancies and the immune host response.

Membrane Repairing Capability of Non-Small Cell Lung Cancer Cells Is Regulated by Drug Resistance and Epithelial-Mesenchymal-Transition

The plasma membrane separates the interior of the cells from the extracellular fluid and protects the cell from disruptive external factors. Therefore, the self-repairing capability of the membrane is crucial for cells to maintain homeostasis and survive in a hostile environment. Here, we found that micron-sized membrane pores induced by cylindrical atomic force microscope probe puncture resealed significantly (~1.3-1.5 times) faster in drug-resistant non-small cell lung cancer (NSCLC) cell lines than in their drug-sensitive counterparts. Interestingly, we found that such enhanced membrane repairing ability was due to the overexpression of annexin in drug-resistant NSCLC cells. In addition, a further ~50% reduction in membrane resealing time (i.e., from ~23 s to ~13 s) was observed through the epithelial-mesenchymal-transition, highlighting the superior viability and potential of highly aggressive tumor cells using membrane resealing as an indicator for assessing the drug-resistivity and pathological state of cancer.

A novel DNA aptamer targeting lung cancer stem cells exerts a therapeutic effect by binding and neutralizing Annexin A2

Cancer remains one of the leading causes of death worldwide. Cancer stem cells (CSCs) are the underlying reason for tumor recurrence, progression, and therapeutic resistance. Aptamers are synthetic single-stranded oligonucleotides that can specifically bind to various molecular targets. Here, we aim to develop an effective aptamer-based biomarker and therapeutic tool that targets CSCs for cancer therapy. We perform whole-cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) to screen DNA aptamers that specifically bound to lung CSCs, modeled by E-cadherin-silenced A549 cells. We develop a CSC-specific aptamer (AP-9R) specifically recognizing lung CSCs with high affinity and identify Annexin A2, a Ca²⁺-dependent membrane-binding protein, as its target. Annexin A2 expression was upregulated in lung CSCs and involved in cancer stemness. The expression of Annexin A2 was associated with signatures of stemness and metastasis, as well as poor clinical outcomes, in lung cancer in silico. Moreover, AP-9R decreased Annexin A2 expression and suppressed CSC properties in CSCs in vitro and in vivo. The present findings suggest that Annexin A2 is a CSC marker and regulator, and the CSC-specific aptamer AP-9R has potential theranostic applications for lung cancer.

Encephalomyocarditis Virus 2A Protein Inhibited Apoptosis by Interaction with Annexin A2 through JNK/c-Jun Pathway

Encephalomyocarditis virus can cause myocarditis and encephalitis in pigs and other mammals, thus posing a potential threat to public health safety. The 2A protein is an important virulence factor of EMCV. Previous studies have shown that the 2A protein may be related to the inhibition of apoptosis by virus, but its specific molecular mechanism is not clear. In this study, the 2A protein was expressed in Escherichia coli in order to find interacting cell proteins. A pull down assay, coupled with mass spectrometry, revealed that the 2A protein possibly interacted with annexin A2. Co-immunoprecipitation assays and confocal imaging analysis further demonstrated that the 2A protein interacted with annexin A2 in cells. In reducing the expression of annexin A2 by siRNA, the ability of the 2A protein to inhibit apoptosis was weakened and the proliferation of EMCV was slowed down. These results suggest that annexin A2 is closely related to the inhibition of apoptosis by 2A. Furthermore, both RT-PCR and western blot results showed that the 2A protein requires annexin A2 interaction to inhibit apoptosis via JNK/c-Jun pathway. Taken together, our data indicate that the 2A protein inhibits apoptosis by interacting with annexin A2 via the JNK/c-Jun pathway. These findings provide insight into the molecular pathogenesis underlying EMCV infection.

LIM-Domain-Binding Protein 1 Mediates Cell Proliferation and Drug Resistance in Colorectal Cancer

Objective: It has been shown that LIM-domain-binding protein 1 (LDB1) is involved in the tumorigenesis of several cancers, but its function in colorectal cancer (CRC) has not been fully explained. This study is aimed to investigate whether LDB1 is involved in regulating the cell growth and drug sensitivity of CRC.

Methods: To analyze the protein expression of LDB1 in CRC tissues, western blot was used. KM plotter and UALCAN databases were used to predict the prognosis of CRC patients with low or high LDB1 expression. To do the correlation analysis in CRC tissues, GEPIA database was used. CCK-8 assay and xenograft models were used to evaluate the effects of LDB1 in CRC cell growth. An oxaliplatin-resistant cell line was constructed to evaluate the effect of LDB1 in drug sensitivity of CRC cells.

Results: Our current research confirmed that LDB1 was upregulated in CRC tumor tissues, and its elevation predicted a poor prognosis for CRC patients. LDB1 was also found positively correlated with CCNA1, BCL2 and BCLW, but negatively correlated with the pro-apoptotic signals (BID, BAX and BAK). Silence of LDB1 significantly inhibited CRC cell growth in vitro, and CRC cells with low expression of LDB1 had a lower tumorigenesis rate in tumor-bearing nude mice. Our experiments also showed that LDB1 silence enhanced the anti-tumor activity of oxaliplatin in CRC cells. The expression of LDB1 was also found increased in oxaliplatin-resistant CRC cell lines, and silence of LDB1 partly restored the antitumor effect of oxaliplatin in an oxaliplatin-resistant CRC cell line.

Conclusion: Our current results revealed the roles of LDB1 in the growth and drug resistance of CRC cells, and may provide the new theoretical support for LDB1 as a potential target for the treatment of CRC in the future.

Tracing the evolution of aneuploid cancers by multiregional sequencing with CRUST

Clonal deconvolution of mutational landscapes is crucial to understand the evolutionary dynamics of cancer. Two limiting factors for clonal deconvolution that have remained unresolved are variation in purity and chromosomal copy number across different samples of the same tumor. We developed a semi-supervised algorithm that tracks variant calls through multi-sample spatiotemporal tumor data. While normalizing allele frequencies based on purity, it also adjusts for copy number changes at clonal deconvolution. Absent à priori copy number data, it renders in silico copy number estimations from bulk sequences. Using published and simulated tumor sequences, we reliably segregated clonal/subclonal variants even at a low sequencing depth (~50×). Given at least one pure tumor sample (>70% purity), we could normalize and deconvolve paired samples down to a purity of 40%. This renders a reliable clonal reconstruction well adapted to multi-regionally sampled solid tumors, which are often aneuploid and contaminated by non-cancer cells.

A monoclonal antibody against annexin A2 targets stem and progenitor cell fractions in tumors

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Development of a novel antibody (termed as mAb150) developed in our lab which targets annexin A2.

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Although there are earlier reports of another monoclonal antibody with the same target, the epitope recognized by mAb150 is novel.

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mAb150 is specifically recognized to target the achilles heel of cancer viz. cancer stem cells and progenitors that persist after treatments and potentially give rise to minimal residual disease.

The involvement of cancer stem cells (CSCs) in driving tumor dormancy and drug resistance is well established. Most therapeutic regimens however are ineffective in targeting these regenerative populations. We report the development and evaluation of a monoclonal antibody, mAb150, which targets the metastasis associated antigen, Annexin A2 (AnxA2) through recognition of a N-terminal epitope. Treatment with mAb150 potentiated re-entry of CSCs into the cell cycle that perturbed tumor dormancy and facilitated targeting of CSCs as was validated by in vitro and in vivo assays. Epigenetic potentiation further improved mAb150 efficacy in achieving total tumor regression by targeting regenerative populations to achieve tumor regression, specifically in high-grade serous ovarian adenocarcinoma.

LncRNA MIR155HG induces M2 macrophage polarization and drug resistance of colorectal cancer cells by regulating ANXA2

OBJECTIVE

To investigate the effects of lncRNA MIR155HG and Annexin A2 (ANXA2) on colorectal cancer (CRC) and the mechanism of the MIR155HG/ANXA2 axis.

METHODS

The expressions of MIR155HG and ANXA2 in human CRC tissues were analyzed for association with pathological characteristics and prognosis of CRC patients. CRC cell lines (Caco2 and HT29) were used to study the effects of MIR155HG or ANXA2 knockdown on tumor cell behaviors and macrophage polarization as well as the effect of M2 polarization on oxaliplatin resistance of CRC cells. RNA immunoprecipitation, RNA pull-down and dual-luciferase reporter assays were applied to verify the targeting relationships among MIR155HG, miR-650 and ANXA2. Heterotopic xenograft models were established to verify the results of cell experiments.

RESULTS

MIR155HG and ANXA2 were highly expressed in CRC tissues/cells and of prognostic values for CRC patients. Knockdown of MIR155HG or ANXA2 suppressed M2 macrophage polarization, and proliferation, migration, invasion and oxaliplatin resistance of CRC cells. MIR155HG competed with ANXA2 for binding miR-650 and can also directly target ANXA2. Knockdown of MIR155HG or ANXA2 also inhibited M2 macrophage polarization and CRC progression in nude mice.

CONCLUSION

This study highlighted that MIR155HG, by regulating the miR-650/ANXA2 axis, promotes CRC progression and enhances oxaliplatin resistance in CRC cells through M2 macrophage polarization.

mRNA expression level of CDH2, LEP, POSTN, TIMP1 and VEGFC modulates 5-fluorouracil resistance in colon cancer cells

Drug resistance severely affects the clinical efficacy of therapeutic agents in patients with colon cancer. The aim of the present study was to identify genes involved in drug resistance in colon cancer using bioinformatics analysis and to identify the underlying mechanisms in vitro. Genes associated with cancer recurrence and chemotherapy resistance were identified using data mining. Immunohistochemistry was performed to analyze the protein expression level of genes of interest in human colon cancer tissues. Reverse transcription-quantitative PCR analysis was performed to analyze the gene expression level in patient samples and in colon cancer cell lines (HCT116 and LoVo). Cell viability was evaluated using the Cell Counting Kit-8 assay in the colon cancer cell lines. Apoptosis was measured using PI staining. The results from the present study revealed 602 genes using both ‘cancer recurrence’ and ‘chemoresistance’ terms on the GenCLiP3 website. Gene functional annotation was performed using the Database for Annotation, Visualization and Integrated Discovery then, the protein-protein interaction networks of the 602 genes were analyzed using STRING analysis. Further, in the GEPIA database, 14 genes (ATM, CDH2, CDKN2A, EPO, LEP, TGFB1, TIMP1, PGR, VEGFC, POSTN, BCL6, CYP19A1, NOTCH3 and XPA) were found to be upregulated in colon cancer tissue and were associated with poor prognosis in patients with colon cancer. Further analysis of 33 paired human colon cancer tissues revealed that 8 genes (ATM, CDH2, CDKN2A, LEP, PGR, TIMP1, POSTN and VEGFC) were significantly upregulated, which was consistent with the results obtained from the earlier analysis and 5 genes (CDH2, LEP, POSTN, TIMP1 and VEGFC) were associated with patient prognosis. Silencing of these 5 genes using small interfering RNAs significantly enhanced the sensitivity of colon cancer cells to the chemotherapeutic agent, 5-fluorouracil (5-FU). Taken together, the results suggested that CDH2, LEP, POSTN, TIMP1 and VEGFC might play a role in chemotherapeutic resistance in colon cancer and represent potential targets for overcoming 5-FU resistance in colon cancer.

Life after Cell Death-Survival and Survivorship Following Chemotherapy

Simple Summary

Treatment of aggressive cancers often relies on chemotherapy. This treatment has improved survival rates, but while effective at killing cancer cells, inevitably it also kills or alters the function of others. While many of the known effects are transient and resolve after treatment, as survival rates increase, so does our understanding of the long-term health costs that accompany cancer survivors. Here we provide an overview of common long-term morbidities known to be caused by conventional chemotherapy, including the risk of relapse, but more importantly, the cost of quality of life experienced, especially by those who have cancer in early life. We aim to highlight the importance of the development of targeted therapies to replace the use of conventional chemotherapy, but also that of treating the patients along with the disease to enable not only longer but also healthier life after cancer.

Abstract

To prevent cancer cells replacing and outnumbering their functional somatic counterparts, the most effective solution is their removal. Classical treatments rely on surgical excision, chemical or physical damage to the cancer cells by conventional interventions such as chemo- and radiotherapy, to eliminate or reduce tumour burden. Cancer treatment has in the last two decades seen the advent of increasingly sophisticated therapeutic regimens aimed at selectively targeting cancer cells whilst sparing the remaining cells from severe loss of viability or function. These include small molecule inhibitors, monoclonal antibodies and a myriad of compounds that affect metabolism, angiogenesis or immunotherapy. Our increased knowledge of specific cancer types, stratified diagnoses, genetic and molecular profiling, and more refined treatment practices have improved overall survival in a significant number of patients. Increased survival, however, has also increased the incidence of associated challenges of chemotherapy-induced morbidity, with some pathologies developing several years after termination of treatment. Long-term care of cancer survivors must therefore become a focus in itself, such that along with prolonging life expectancy, treatments allow for improved quality of life.

Interaction of FLNA and ANXA2 promotes gefitinib resistance by activating the Wnt pathway in non-small-cell lung cancer

Lung cancer is still a main cause of cancer-related death worldwide. Non-small-cell lung cancer (NSCLC) accounts for the majority of lung cancers, and gefitinib is an effective targeted drug for NSCLC. It is important to explore the underlying molecular mechanisms of gefitinib resistance to provide new treatment strategies and to improve the prognosis of gefitinib-resistant NSCLC patients. This study aimed to examine the role of filamin A (FLNA) in acquired resistance to gefitinib in NSCLC, and identify ANXA2 (annexin A2), one of calcium-dependent phospholipid-binding proteins, as its corresponding regulatory factor. First, we established resistant cells via long-term exposure to gefitinib to analyse the association between FLNA and gefitinib resistance. Through quantitative real-time polymerase chain reaction (qRT-PCR), Cell Counting Kit-8 (CCK-8), western blotting (WB), and flow cytometry assays, we evaluated the role of FLNA. The effect of FLNA knockdown or overexpression was analysed not only in cell lines but also in mouse models. We verified the FLNA-interacting protein through coimmunoprecipitation (CoIP) experiments and found that the downstream signalling pathway was regulated by FLNA and its interacting protein. Finally, the upstream transcription factor was identified by chromatin immunoprecipitation (ChIP). Increased FLNA expression induced gefitinib resistance. Knockdown of FLNA restored gefitinib sensitivity and induced apoptosis in vivo and in vitro. FLNA and ANXA2 cooperatively led to the activation of the Wnt pathway, which was closely linked to gefitinib resistance. Subsequently, SP1 promoted transcriptional activation of FLNA to regulate gefitinib resistance. We determined that FLNA serves as a regulator of gefitinib resistance in NSCLC and found that FLNA and ANXA2 together induced gefitinib resistance by activating the Wnt pathway.

Advances in cancer treatment: a new therapeutic target, Annexin A2

Annexin A2 (ANXA2) is a calcium regulated phospholipid-binding protein. It is expressed in some tumor cells, endothelial cells, macrophages, and mononuclear cells, affecting cell survival and mediating interactions between intercellular and extracellular microenvironment. Aberrant expression of ANXA2 can be used as a potential predictive factor, diagnostic biomarker and therapeutic target in cancer therapy. Investigators used various technologies to target ANXA2 in a preclinical model of human cancers and demonstrated encouraging results. In this review article, we discuss the diagnosis and prognosis latent capacity of ANXA2 in progressive cancers, focus on the exploration of restorative interventions targeting ANXA2 in cancer treatment. Further, we comment on a promising candidate therapy that is conceivable for clinical translation.

Metformin impairs cisplatin resistance effects in A549 lung cancer cells through mTOR signaling and other metabolic pathways

Lung cancer is the leading cause of cancer‑associated death worldwide and exhibits intrinsic and acquired therapeutic resistance to cisplatin (CIS). The present study investigated the role of mTOR signaling and other signaling pathways after metformin (MET) treatment in control and cisplatin‑resistant A549 cells, mapping pathways and possible targets involved in CIS sensitivity. MTT, flow cytometry, clonogenic assay, western blotting, proteomic analysis using the Stable Isotope Labeling by Amino acids in Cell culture (SILAC) approach and reverse transcription‑quantitative PCR were performed. The results revealed that CIS treatment induced mTOR signaling pathway overactivation, and the mTOR status was restored by MET. MET and the mTOR inhibitor rapamycin (RAPA) decreased the viability in control and resistant cells, and decreased the cell size increase induced by CIS. In control cells, MET and RAPA decreased colony formation after 72 h and decreased IC₅₀ values, potentiating the effects of CIS. Proteomics analysis revealed important pathways regulated by MET, including transcription, RNA processing and IL‑12‑mediated signaling. In CIS‑resistant cells, MET regulated the apoptotic process, oxidative stress and G₂/M transition. Annexin 4 (ANXA4) and superoxide dismutase 2 (SOD2), involved in apoptosis and oxidative stress, respectively, were chosen to validate the SILAC analysis and may represent potential therapeutic targets for lung cancer treatment. In conclusion, the chemosensitizing and antiproliferative effects of MET were associated with mTOR signaling and with potential novel targets, such as ANXA4 and SOD2, in human lung cancer cells.

Annexin Animal Models-From Fundamental Principles to Translational Research

Routine manipulation of the mouse genome has become a landmark in biomedical research. Traits that are only associated with advanced developmental stages can now be investigated within a living organism, and the in vivo analysis of corresponding phenotypes and functions advances the translation into the clinical setting. The annexins, a family of closely related calcium (Ca²⁺)- and lipid-binding proteins, are found at various intra- and extracellular locations, and interact with a broad range of membrane lipids and proteins. Their impacts on cellular functions has been extensively assessed in vitro, yet annexin-deficient mouse models generally develop normally and do not display obvious phenotypes. Only in recent years, studies examining genetically modified annexin mouse models which were exposed to stress conditions mimicking human disease often revealed striking phenotypes. This review is the first comprehensive overview of annexin-related research using animal models and their exciting future use for relevant issues in biology and experimental medicine.

Mechanisms of tRNA-derived fragments and tRNA halves in cancer treatment resistance

The tRNA-derived fragments (tRFs) and tRNA halves (tiRNAs) are newly discovered noncoding RNAs in recent years. They are derived from specific cleavage of mature and pre-tRNAs and expressed in various cancers. They enhance cell proliferation and metastasis or inhibit cancer progression. Many studies have investigated their roles in the diagnosis, progression, metastasis, and prognosis of various cancers, but the mechanisms through which they are involved in resistance to cancer treatment are unclear. This review outlines the classification of tRFs and tiRNAs and their mechanisms in cancer drug resistance, thus providing new ideas for cancer treatment.

SNHG9 was upregulated in NSCLC and associated with DDP-resistance and poor prognosis of NSCLC patients

Lung cancer, a leading cause of cancer-related mortalities worldwide and non-small cell lung cancer (NSCLC) is the main subtype of lung cancer. As a first-line chemotherapeutic drug used for NSCLC, acquired resistance retarded the clinical application of cisplatin (DDP). We herein reported long non-coding RNA SNHG9 was over-expressed in NSCLC tissues and cell lines compared with normal lung tissues and cell line; Increased SNHG9 was also observed in DDP resistant NSCLC tissues and cell lines compared with their DDP sensitive counterparts. Elevated expression of SNHG9 was associated with lower overall survival (OS) rate in NSCLC patients. Besides, silence of SNHG9 suppressed DDP resistance of NSCLC cells. Furthermore, CAPRIN1 was positively regulated by SNHG9 and mediated the promoting role of SNHG9 in DDP resistance of NSCLC cells. SNHG9 could be used as a potential target for DDP resistant NSCLC therapy.

Reelin Promotes Cisplatin Resistance by Induction of Epithelial-Mesenchymal Transition via p38/GSK3β/Snail Signaling in Non-Small Cell Lung Cancer

Background

Emerging evidence suggests the involvement of Reelin in chemoresistance in various cancers. However, its function in cisplatin (DDP) sensitivity of non-small cell lung cancer (NSCLC) needs to be investigated.

Material/Methods

Reelin expression in cisplatin-sensitive A549 cells and cisplatin-resistant NSCLC (A549/DDP) cells was analyzed by western blot analysis. qRT-PCR, western blotting, immunofluorescence, CCK-8 assays, Annexin V/propidium iodide apoptosis assay, and Transwell migration assays were carried out to determine the function of Reelin on DDP resistance.

Results

Reelin was markedly increased in A549/DDP cells relative to A549 cells. Knockdown of Reelin enhanced DDP chemosensitivity of A549/DDP cells, whereas overexpression of Reelin enhanced DDP resistance of A549, H1299, and H460 cells. Reelin induced DDP resistance in NSCLC cells via facilitating epithelial-mesenchymal transition (EMT). Furthermore, Reelin modulated p38/GSK3β signal transduction and promoted Snail (EMT-associated transcription factor) expression. Suppression of p38/Snail reversed Reelin-induced EMT and resistance of NSCLC cells to DDP.

Conclusions

These data indicated that Reelin induces DDP resistance of NSCLC by regulation of the p38/GSK3β/Snail/EMT signaling pathway and provide evidence that Reelin suppression can be an effective strategy to suppress DDP resistance in NSCLC.

Ginsenoside Rh1 Alleviates HK-2 Apoptosis by Inhibiting ROS and the JNK/p53 Pathways

Background

Cisplatin is widely used in the treatment of malignant patients; however, its adverse nephrotoxic effects limit its clinical use. Ginsenoside Rh1 is a main component of ginseng and has many pharmaceutical effects, including immunomodulatory effects.

Objective

The objective of this research is to assess the effects of ginsenoside Rh1 on a cisplatin-induced HK-2 injury model and to study its potential effect mechanisms.

Methods

HK-2 cell vitality was assessed via Cell Counting Kit-8 (CCK-8) assay. Carboxyfluorescein succinimidyl ester/propidium iodide (CFSF/PI) staining was used to detect the apoptosis of HK-2 cells. ROS expression was detected by DCFDA. The expressions of JNK, p53, caspase-3, Bax, and NGAL were detected by western blot.

Results

Ginsenoside Rh1 was found to increase the vitality of HK-2 cells and inhibit ROS production and the apoptosis of HK-2 cells in a cisplatin-induced injury model. Ginsenoside Rh1 was found to inhibit the expression of JNK, p53, caspase-3, Bax, and NGAL in a cisplatin-induced injury model.

Conclusion

Ginsenoside Rh1 alleviated HK-2 apoptosis in a cisplatin-induced injury model by inhibiting ROS production and the JNK/p53 pathway. Ginsenoside Rh1 may be a promising drug for the alleviation of cisplatin-induced nephrotoxicity in malignant patients.

Berberine chloride suppresses non-small cell lung cancer by deregulating Sin3A/TOP2B pathway in vitro and in vivo

PURPOSE

Berberine chloride (BBC) is a well-known plant isoquinoline alkaloid derived from Berberis aristata. In this study, we aim to explore the effect of BBC on non-small cell lung cancer (NSCLC), and further expound the underlying mechanism of BBC induces NSCLC cell death in vitro and in vivo.

METHODS

CCK-8 assay and colony formation assay were used to test the viability and colony formation ability of NSCLC cells. Apoptosis analysis was used to analyze the apoptotic cells. siRNAs were utilized to disturb the expression of Sin3A. qPCR and Western blot analysis were employed to determine mRNA and protein levels of related genes and proteins. Tumor xenografts model was used for in vivo detection.

RESULTS

BBC inhibited the proliferation and colony formation of human NSCLC cells in a dose- and time-dependent manner. In addition, BBC induced DNA double-stranded breaks (DSBs) through downregulating TOP2B level, leading to apoptosis in human NSCLC cells. The Chip-seq data of A549 cells obtained from the ENCODE consortium indicate that Sin3A binds on the promoters of TOP2B. Knockdown of Sin3A led to downregulation of TOP2B in human NSCLC cells. Furthermore, BBC decreased Sin3A expression and shortened the half-life of Sin3A, results in downregulation of TOP2B in human NSCLC cells.

CONCLUSION

In this study, we demonstrated a new mechanism that BBC suppresses human NSCLC by deregulating Sin3A/TOP2B pathway, leading to DNA damage and apoptosis in human NSCLC in vitro and in vivo.

Shenmai Injection Supresses Glycolysis and Enhances Cisplatin Cytotoxicity in Cisplatin-Resistant A549/DDP Cells via the AKT-mTOR-c-Myc Signaling Pathway

Tumor cells, especially drug-resistant cells, predominately support growth by glycolysis even under the condition of adequate oxygen, which is known as the Warburg effect. Glucose metabolism reprogramming is one of the main factors causing tumor resistance. Previous studies on Shenmai injection (SMI), a Chinese herbal medicine, have shown enhanced efficacy in the treatment of tumors in combination with chemotherapy drugs, but the mechanism is not clear. In this study, we investigated the effect of SMI combined with cisplatin on cisplatin-resistant lung adenocarcinoma A549/DDP cells. Our results showed that cisplatin-resistant A549/DDP cells exhibited increased glucose consumption, lactate production, and expression levels of key glycolytic enzymes, including hexokinase 2 (HK2), pyruvate kinase M1/2 (PKM1/2), pyruvate kinase M2 (PKM2), glucose transporter 1 (GLUT1), and lactate dehydrogenase A (LDHA), compared with cisplatin-sensitive A549 cells. SMI combined with cisplatin in A549/DDP cells, led to significantly lower expression levels of key glycolytic enzymes, such as HK2, PKM1/2, GLUT1, and pyruvate dehydrogenase (PDH). In addition, we found that the combination of SMI and cisplatin could inhibit cell proliferation and promote apoptosis by reducing the expression levels of p-Akt, p-mTOR, and c-Myc, and then, it reduced the glycolysis level. These results suggest that SMI enhances the antitumor effect of cisplatin via glucose metabolism reprogramming. Therefore, the combination of SMI and cisplatin may be a potential therapeutic strategy to treat cisplatin-resistant nonsmall cell lung cancer.

Ubiquitin ligase CHAF1B induces cisplatin resistance in lung adenocarcinoma by promoting NCOR2 degradation

Background

Lung cancer is the most common malignant tumor in the world. The Whole-proteome microarray showed that ubiquitin ligase chromatin assembly factor 1 subunit B (CHAF1B) expression in A549/DDP cells is higher than in A549 cells. Our study explored the molecular mechanism of CHAF1B affecting cisplatin resistance in lung adenocarcinoma (LUAD).

Methods

Proteome microarray quantify the differentially expressed proteins between LUAD cell line A549 and its cisplatin-resistant strain A549/DDP. Quantitative real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot (WB) confirmed the CHAF1B expression. Public databases analyzed the prognosis of LUAD patients with varied LUAD expression followed by the substrates prediction of CHAF1B. Public databases showed that nuclear receptor corepressor 2 (NCOR2) may be substrates of CHAF1B. WB detected that CHAF1B expression affected the expression of NCOR2. Cell and animal experiments and clinical data detected function and integrating mechanism of CHAF1B compounds.

Results

Proteome chips results indicated that CHAF1B, PPP1R13L, and CDC20 was higher than A549 in A549/DDP. Public databases showed that high expression of CHAF1B, PPP1R13L, and CDC20 was negatively correlated with prognosis in LUAD patients. PCR and WB results indicated higher CHAF1B expression in A549/DDP cells than that in A549 cells. NCOR2 and PPP5C were confirmed to be substrates of CHAF1B. CHAF1B knockdown significantly increased the sensitivity of cisplatin in A549/DDP cells and the upregulated NCOR2 expression. CHAF1B and NCOR2 are interacting proteins and the position of interaction between CHAF1B and NCOR2 was mainly in the nucleus. CHAF1B promotes ubiquitination degradation of NCOR2. Cells and animal experiments showed that under the action of cisplatin, after knockdown of CHAF1B and NCOR2 in A549/DDP group compared with CHAF1B knockdown alone, the cell proliferation and migratory ability increased and apoptotic rate decreased, and the growth rate and size of transplanted tumor increased significantly. Immunohistochemistry suggested that Ki-67 increased, while apoptosis-related indicators caspase-3 decreased significantly. Clinical data showed that patients with high expression of CHAF1B are more susceptible to cisplatin resistance.

Conclusion

Ubiquitin ligase CAHF1B can induce cisplatin resistance in LUAD by promoting the ubiquitination degradation of NCOR2.

[Role of P21 in Resistance of Lung Cancer]

Lung cancer is the most common malignant tumor in the world with the highest incidence of deaths. In recent years, the treatment of lung cancer has made a significant breakthrough. However, as the tumor progresses, lung cancer cells inevitably acquire resistance and the efficacy of the treatment are greatly reduced. P21 protein plays a dual role in tumors, which not only regulates the cell cycle, induces apoptosis, inhibits cell proliferation, but also protects cells against apoptosis and promotes tumor cell resistance. This article reviews the research on P21 and lung cancer resistance, to provide new ideas for individualized treatment of lung cancer and overcoming lung cancer resistance.

Annexin A2 promotion of hepatocellular carcinoma tumorigenesis via the immune microenvironment

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with a dismal prognosis, especially when diagnosed at advanced stages. Annexin A2 (ANXA2), is found to promote cancer progression and therapeutic resistance. However, the underlining mechanisms of ANXA2 in immune escape of HCC remain poorly understood up to now. Herein, we summarized the molecular function of ANXA2 in HCC and its relationship with prognosis. Furthermore, we tentatively elucidated the underlying mechanism of ANXA2 immune escape of HCC by upregulating the proportion of regulatory T cells and the expression of several inhibitory molecules, and by downregulating the proportion of natural killer cells and dendritic cells and the expression of several inhibitory molecules or effector molecules. We expect a lot of in-depth studies to further reveal the underlying mechanism of ANXA2 in immune escape of HCC in the future.

WDHD1 Leads to Cisplatin Resistance by Promoting MAPRE2 Ubiquitination in Lung Adenocarcinoma

Ubiquitin ligases have been shown to regulate drug sensitivity. This study aimed to explore the role of the ubiquitin ligase WD repeat and HMG-box DNA binding protein 1 (WDHD1) in regulating cisplatin sensitivity in lung adenocarcinoma (LUAD). A quantitative analysis of the global proteome identified differential protein expression between LUAD A549 cells and the cisplatin-resistant strain A549/DDP. Public databases revealed the relationship between ubiquitin ligase expression and the prognosis of patients with LUAD. Quantitative real-time polymerase chain reaction and Western blotting were used to estimate the WDHD1 expression levels. Analysis of public databases predicted the substrate of WDHD1. Western blotting detected the effect of WDHD1 on microtubule-associated protein RP/EB family member 2 (MAPRE2) and DSTN. Functional analysis of MAPRE2 verified the interaction between WDHD1 and MAPRE2, as well as the interacting sites by methyl-thiazolyl-tetrazolium assay and flow cytometry, immunoprecipitation, protein stability, and immunofluorescence. Cell and animal experiments confirmed the effect of WDHD1 and MAPRE2 on cisplatin sensitivity in LUAD. Clinical data evaluated the impact of WDHD1 expression level on cisplatin sensitivity. Quantitative analysis of the global proteome revealed ubiquitin-dependent protein catabolism to be more active in A549/DDP cells than in A549 cells. WDHD1 expression was higher in A549/DDP cells than in A549 cells, and knocking out WDHD1 increased the sensitivity of A549/DDP cells to cisplatin. WDHD1 overexpression negatively correlated with the overall survival of LUAD patients. We observed that MAPRE2 was upregulated when WDHD1 was knocked out. A MAPRE2 knockout in A549 cells resulted in increased cell viability while decreasing apoptosis when the A549 cells exposed to cisplatin. WDHD1 and MAPRE2 were found to interact in the nucleus, and WDHD1 promoted the ubiquitination of MAPRE2. Following cisplatin exposure, the WDHD1 and MAPRE2 knockout groups facilitated cell proliferation and migration, inhibited apoptosis in A549/DDP cells, decreased apoptosis, and increased tumor size and growth rate in animal experiments. Immunohistochemistry showed that Ki67 levels increased, and levels of apoptotic indicators significantly decreased in the WDHD1 and MAPRE2 knockout groups. Clinical data confirmed that WDHD1 overexpression negatively correlated with cisplatin sensitivity. Thus, the ubiquitin ligase WDHD1 induces cisplatin resistance in LUAD by promoting MAPRE2 ubiquitination.

Understanding MAPK Signaling Pathways in Apoptosis

MAPK (mitogen-activated protein kinase) signaling pathways regulate a variety of biological processes through multiple cellular mechanisms. In most of these processes, such as apoptosis, MAPKs have a dual role since they can act as activators or inhibitors, depending on the cell type and the stimulus. In this review, we present the main pro- and anti-apoptotic mechanisms regulated by MAPKs, as well as the crosstalk observed between some MAPKs. We also describe the basic signaling properties of MAPKs (ultrasensitivity, hysteresis, digital response), and the presence of different positive feedback loops in apoptosis. We provide a simple guide to predict MAPKs’ behavior, based on the intensity and duration of the stimulus. Finally, we consider the role of MAPKs in osmostress-induced apoptosis by using Xenopus oocytes as a cell model. As we will see, apoptosis is plagued with multiple positive feedback loops. We hope this review will help to understand how MAPK signaling pathways engage irreversible cellular decisions.

Annexin A13 predicts poor prognosis for lung adenocarcinoma patients and accelerates the proliferation and migration of lung adenocarcinoma cells by modulating epithelial-mesenchymal transition

This study aimed to investigate the role of ANXA13 in lung adenocarcinoma (LUAD) growth, migration, and the underlying mechanisms. Firstly, in the TCGA dataset for LUAD, ANXA13 is found to be highly expressed in patients with LUAD and high expression of ANXA13 predicted poor outcomes in LUAD patients. Consistently, the data of qRT-PCR showed that the expression of ANXA13 was higher in LUAD cell lines (Calu-3, LTEP-a-2, and NCI-H1395) than that in normal lung cell line BEAS2B. Then, we performed gain- and loss of function of ANXA13 in NCI-H1395 and Calu-3 cells, respectively. The results displayed that deficiency of ANXA13 suppresses cell proliferation, invasion, and migration in Calu-3 cells and overexpression of ANXA13 augments cell proliferation, invasion, and migration in NCI-H1395 cells. Finally, it was found that silencing of ANXA13 obviously raised the protein expression levels of E-cadherin and reduced the protein levels of N-cadherin, Vimentin, and Snail in Calu-3 cells whereas overexpression of ANXA13 obviously receded the protein expression levels of E-cadherin and enhanced the protein levels of N-cadherin, Vimentin, and Snail in NCI-H1395 cells. This study analyzed the biological effects of ANXA13 in LUAD cells, indicating that ANXA13 could regard as a therapeutic target for LUAD.

Targeting MAPK Signaling in Cancer: Mechanisms of Drug Resistance and Sensitivity

Mitogen-activated protein kinase (MAPK) pathways represent ubiquitous signal transduction pathways that regulate all aspects of life and are frequently altered in disease. Here, we focus on the role of MAPK pathways in modulating drug sensitivity and resistance in cancer. We briefly discuss new findings in the extracellular signaling-regulated kinase (ERK) pathway, but mainly focus on the mechanisms how stress activated MAPK pathways, such as p38 MAPK and the Jun N-terminal kinases (JNK), impact the response of cancer cells to chemotherapies and targeted therapies. In this context, we also discuss the role of metabolic and epigenetic aberrations and new therapeutic opportunities arising from these changes.

FKBP51 induces p53-dependent apoptosis and enhances drug sensitivity of human non-small-cell lung cancer cells

Lung cancer is one of the most prevalent cancer types worldwide, and non-small-cell lung cancer (NSCLC) accounts for ~85% of all lung cancer cases. Despite the notable prevalence of NSCLC, the mechanisms underlying its progression remain unclear. The present study investigated the involvement of FK506-binding protein 51 (FKBP51) in NSCLC development and determined the factors associated with FKBP51 modification for NSCLC treatment. Immunohistochemical analysis was performed to analyze FKBP51 expression in human NSCLC tissue samples. Additionally, flow cytometry was performed to observe the apoptosis of FKBP51-overexpressing A549 cells. A dual-luciferase reporter assay was performed to confirm the association between FKBP51 and p53 expression, and western blotting was performed to analyze the effects of FKBP51 on the p53 signaling pathway. Finally, cell viability was measured using a Cell Counting Kit-8 assay. The results suggested FKBP51 downregulation in human lung cancer. Furthermore, apoptosis rates may be increased in FKBP51-overexpressing A549 cells. Moreover, FKBP51 promoted p53 expression and subsequent p53 signaling pathway activation. These results indicated that FKBP51 promoted A549 cell apoptosis via the p53 signaling pathway. Additionally, FKBP51 enhanced the sensitivity of A549 cells to cisplatin. Collectively, these data suggested that FKBP51 could serve as a biomarker for human lung cancer and can thus be tailored for incorporation into NSCLC therapy in the future.

LncRNAGAS5 sponges miRNA-221 to promote neurons apoptosis by up-regulated PUMA under hypoxia condition

Objectives: Long noncoding RNAs (lncRNAs) play substantial roles in cerebral ischemia. Growth arrest-specific 5 (GAS5) was reported to be involved in stroke. In the present study, we aimed to investigate the roles of GAS5 in cerebral condition and unveil the underlying mechanism.Method: Transient focal ischemia was induced by intraluminal occlusion of the right Middle cerebral artery occlusion (MCAO) and 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to evaluate the volume of cerebral infarction. RT-qPCR was applied to evaluate the level of GAS5 and miR-221. Fluorescence activated Cell Sorting (FACS) and Terminal deoxynucleotidyl transferased (TUNEL)  were used for detection of apoptosis. Western blotting was applied for protein level. Luciferase assay was applied to reveal the underlying relationship between GAS5 and miR-221 or p53-upregulated modulator of apoptosis (PUMA) and miR-221.Results: The results indicated that GAS5 was up-regulated in MCAO rats and in vitro hypoxia cell model while miR-221 expression was decreased in vitro hypoxia cell model. GAS5 promoted cells apoptosis, while miR-221 inhibited cell apoptosis through regulation of PUMA and downstream JNK/H2AX signaling. Moreover, GAS5 and miR-221 have direct interaction and PUMA was the target of miR-221, indicating that GAS5 regulated PUMA through sponging miR-221.Conclusions: the present study revealed that GAS5 aggravated cell apoptosis in hypoxia condition via miR-221/PUMA axis, which may provide potential targets for the treatment of stroke.

miR-125a-5p inhibits tumorigenesis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent and deadly cancers world-wide. miR-125a-5p is a tumor suppressor in HCC and other cancers, but its mechanisms of action during HCC tumorigenesis remain largely unknown. In this study, we found that miR-125a-5p expression was significantly lower in HCC tissues and cell lines than matched normal tissues and liver cells. miR-125a-5p overexpression inhibited HCC cell proliferation and induced apoptosis in vitro and in vivo, while miR-125a-5p knockdown had the opposite effects. In addition, PTPN1 and MAP3K11 were identified as targets of miR-125a-5p. Knocking down PTPN1 and MAP3K11 activated the JNK MAPK signaling pathway to suppress HCC cell proliferation and induce apoptosis. Our findings suggest that miR-125a-5p may be a useful therapeutic target for treatment of HCC patients.

High Co-expression of Large Tenascin C Splice Variants in Stromal Tissue and Annexin A2 in Cancer Cell Membranes is Associated with Poor Prognosis in Pancreatic Cancer

BACKGROUND

Pancreatic cancer tissue contains abundant stromal components, including extracellular matrix proteins such as tenascin C (TNC), which exists as large (TNC-L) and non-large splice variants. Here, we examined human pancreatic cancer specimens for the expression of total TNC (TNC-ALL) and TNC-L in the stroma and annexin A2 (ANXA2), a cell surface receptor for TNC, and evaluated their significance as prognostic markers for pancreatic cancer.

METHODS

Expression of ANXA2, TNC-ALL, and TNC-L was examined in 106 pancreatic cancer tissues from patients who underwent curative resection and who had not received prior therapy or surgery. Protein expression was measured by immunohistochemistry and scored on a semi-quantitative scale. The relationships between protein expression, clinicopathological factors, and prognosis were evaluated by Cox proportional hazards analysis.

RESULTS

TNC-ALL and TNC-L were detected mainly in the stroma, whereas ANXA2 was predominantly expressed in cancer cell membranes. TNC-ALL was also expressed in non-tumor pancreatic tissue. High levels of stromal TNC-L and membranous ANXA2, but not stromal TNC-ALL, were independently associated with cancer progression and poor prognosis. Moreover, high co-expression of stromal TNC-L and membranous ANXA2 was a superior indicator of poor prognosis compared with detection of TNC-ALL, TNC-L, or ANXA2 alone.

CONCLUSIONS

Our data suggest that co-expression of stromal TNC-L and membranous ANXA2 is a poor prognostic marker compared with detection of TNC-L or ANXA2 alone for pancreatic cancer patients. Additionally, targeting of crosstalk between stromal TNC and cancer cell ANXA2 could be a promising therapeutic strategy to overcome refractory pancreatic cancer.