EMT, cancer stem cells and drug resistance: an emerging axis of evil in the war on cancer

TP53AIP1 induce autophagy via the AKT/mTOR signaling pathway in the breast cancer cells

Breast cancer ranks the first in the incidence of female cancer and is the most common cancer threatening the life and health of women worldwide.Tumor protein p53-regulated apoptosis-inducing protein 1 (TP53AIP1) is a pro-apoptotic gene downstream of p53. However, the role of TP53AIP1 in BC needs to be investigated. In vitro and in vivo experiments were conducted to assess the biological functions and associated mechanisms. Several bioinformatics analyses were made, CCK8 assay, wound healing, transwell assays, colony formation assay, EDU, flow cytometry, Immunofluorescence, qRT-PCR and Western-blotting were performed. In our study, we discovered that BC samples had low levels of TP53AIP1 expression, which correlated with a lower survival rate in BC patients. When TP53AIP1 was up-regulated, it caused a decrease in cell proliferation, migration, and invasion. It also induced epithelial-to-mesenchymal transition (EMT) and protective autophagy. Furthermore, the over-expression of TP53AIP1 suppressed tumor growth when tested in vivo. We also noticed that TP53AIP1 up-regulation resulted in decreased levels of phosphorylation in AKT and mTOR, suggesting a mechanistic role. In addition, we performed functional rescue experiments where the activation of AKT was able to counteract the impact of TP53AIP1 on the survival and autophagy in breast cancer cell lines. This suggests that TP53AIP1 acts as an oncogene by controlling the AKT/mTOR pathway. These findings reveal TP53AIP1 as a gene that suppresses tumor growth and triggers autophagy through the AKT/mTOR pathway in breast cancer cells. As a result, TP53AIP1 presents itself as a potential target for novel therapeutic approaches in treating breast cancer.

Cytoglobin attenuates melanoma malignancy but protects melanoma cells from ferroptosis

Cutaneous malignant melanoma is the most aggressive and the deadliest form of skin cancer. There are two types of limitations which universally exist in current melanoma therapy: Adverse effects and reduced efficiency. Cytoglobin (CYGB), an iron hexacoordinated globin, is highly enriched in melanocytes and frequently epigenetically silenced during melanoma genesis. The present study aimed to explore its potential role as a biomarker for ferroptosis treatment. It was observed that B16F10 and A375 melanoma cells with loss of CYGB expression were highly sensitive to ferroptosis inducers RSL3 and erastin, whereas G361 melanoma cells with highly enriched CYGB were resistant to RSL3 or erastin. Ectopically overexpressed CYGB rendered B16F10 and A375 cells resistant to RSL3 or erastin, accompanied by decreased proliferation and epithelial‑mesenchymal transition (EMT). By contrast, knockdown of CYGB expression made G361 cells sensitive to ferroptosis induction but induced proliferation and EMT progression of G361 cells. Mechanistically, CYGB‑induced resistance of melanoma cells to ferroptosis may have been associated, in part, with i) Suppression of EMT; ii) upregulation of glutathione peroxidase 4 expression; iii) decrease of labile iron pool. In vivo study also demonstrated that CYGB overexpression rendered xenograft melanoma much more resist to RSL3 treatment. Based on these findings, CYGB is a potential therapeutic biomarker to screen the melanoma patients who are most likely benefit from ferroptosis treatment.

Cisplatin‑resistant germ cell tumor models: An exploration of the epithelial‑mesenchymal transition regulator SLUG

Germ cell tumors (GCTs) constitute diverse neoplasms arising in the gonads or extragonadal locations. Testicular GCTs (TGCTs) are the predominant solid tumors in adolescents and young men. Despite cisplatin serving as the primary therapeutic intervention for TGCTs, 10‑20% of patients with advanced disease demonstrate resistance to cisplatin‑based chemotherapy, and epithelial‑mesenchymal transition (EMT) is a potential contributor to this resistance. EMT is regulated by various factors, including the snail family transcriptional repressor 2 (SLUG) transcriptional factor, and, to the best of our knowledge, remains unexplored within TGCTs. Therefore, the present study investigated the EMT transcription factor SLUG in TGCTs. In silico analyses were performed to investigate the expression of EMT markers in TGCTs. In addition, a cisplatin‑resistant model for TGCTs was developed using the NTERA‑2 cell line, and a mouse model was also established. Subsequently, EMT was assessed both in vitro and in vivo within the cisplatin‑resistant models using quantitative PCR and western blot analyses. The results of the in silico analysis showed that the different histologies exhibited distinct expression profiles for EMT markers. Seminomas exhibited a lower expression of EMT markers, whereas embryonal carcinomas and mixed GCT demonstrated high expression. Notably, patients with lower SLUG expression had longer median progression‑free survival (46.4 months vs. 28.0 months, P=0.022). In the in vitro analysis, EMT‑associated genes [fibronectin; vimentin (VIM); actin, α2, smooth muscle; collagen type I α1; transforming growth factor‑β1; and SLUG] were upregulated in the cisplatin‑resistant NTERA‑2 (NTERA‑2R) cell line after 72 h of cisplatin treatment. Consistent with this finding, the NTERA‑2R mouse model demonstrated a significant upregulation in the expression levels of VIM and SLUG. In conclusion, the present findings suggested that SLUG may serve a crucial role in connecting EMT with the development of cisplatin resistance, and targeting SLUG may be a putative therapeutic strategy to mitigate cisplatin resistance.

EGCG inhibits migration, invasion and epithelial-mesenchymal transition of renal cell carcinoma by activating TFEB-mediated autophagy

BACKGROUND

The incidence of renal cell carcinoma (RCC) is already in the top ten of all types of cancers, with more than 4 %. Epigallocatechin gallate (EGCG), a polyphenolic compound extracted from green tea, has been shown to be effective in the treatment of various tumors. However, limited studies have demonstrated the effect of EGCG on RCC and its underlying molecular mechanisms.

METHODS

After exposure to gradient concentration (0,5,10,20,40,60,80,100 μM) of EGCG, the cell viability of RCC cells was determined by MTT assay. The migration and invasion abilities of RCC cells were investigated by wound healing and transwell assays. The expression levels of proteins involved in the epithelial-mesenchymal transition (EMT) and autophagy were explored by Western blotting assays. The formation of autophagosome was detected by electron microscope and LC3 puncta assays. Nude mouse xenograft model was used as the model system in vivo.

RESULTS

In the present study, EGCG significantly inhibited the migration, invasion and EMT of RCC cells in a concentrated manner. Further exploration of its mechanism indicated that autophagy is involved in EGCG-mediated metastasis inhibition and EMT inhibition of RCC cells. In addition, EGCG could significantly up-regulate the transcription factor EB (TFEB) and promotes its nuclear localization. The incorporation of TFEB into the nucleus enhanced the transcriptional levels of molecules associated with autophagy. TFEB knockdown inhibited EGCG-mediated autophagy activation, metastasis and EMT inhibition in RCC cells.

CONCLUSIONS

In conclusion, these findings demonstrate for the first time that EGCG inhibits migration, invasion, and EMT of RCC by activating TFEB-mediated autophagy. Therefore, the combination of EGCG and TFFB activators or EMT inhibitors is expected to be a promising therapeutic strategy for RCC.

Targeted therapy approaches for epithelial-mesenchymal transition in triple negative breast cancer

Triple-negative breast cancer (TNBC) is distinguished by negative expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), making it an aggressive subtype of breast cancer and contributes to 15-20% of the total incidence. TNBC is a diverse disease with various genetic variations and molecular subtypes. The tumor microenvironment involves multiple cells, including immune cells, fibroblast cells, extracellular matrix (ECM), and blood vessels that constantly interact with tumor cells and influence each other. The ECM undergoes significant structural changes, leading to induced cell proliferation, migration, adhesion, invasion, and epithelial-to-mesenchymal transition (EMT). The involvement of EMT in the occurrence and development of tumors through invasion and metastasis in TNBC has been a matter of concern. Therefore, EMT markers could be prognostic predictors and potential therapeutic targets in TNBC. Chemotherapy has been one of the primary options for treating patients with TNBC, but its efficacy against TNBC is still limited. Targeted therapy is a critical emerging option with enhanced efficacy and less adverse effects on patients. Various targeted therapy approaches have been developed based on the specific molecules and the signaling pathways involved in TNBC. These include inhibitors of signaling pathways such as TGF-β, Wnt/β-catenin, Notch, TNF-α/NF-κB and EGFR, as well as immune checkpoint inhibitors, such as pembrolizumab, 2laparib, and talazoparib have been widely explored. This article reviews recent developments in EMT in TNBC invasion and metastasis and potential targeted therapy strategies.

Development of a polygenic score predicting drug resistance and patient outcome in breast cancer

Gene expression profiles of hundreds of cancer cell-lines and the cell-lines' response to drug treatment were analyzed to identify genes whose expression correlated with drug resistance. In the GDSC dataset of 809 cancer cell lines, expression of 36 genes were associated with drug resistance (increased IC50) to many anti-cancer drugs. This was validated in the CTRP dataset of 860 cell lines. A polygenic score derived from the correlation coefficients of the 36 genes in cancer cell lines, UAB36, predicted resistance of cell lines to Tamoxifen. Although the 36 genes were selected from cell line behaviors, UAB36 successfully predicted survival of breast cancer patients in three different cohorts of patients treated with Tamoxifen. UAB36 outperforms two existing predictive gene signatures and is a predictor of outcome of breast cancer patients independent of the known clinical co-variates that affect outcome. This approach should provide promising polygenic biomarkers for resistance in many cancer types against specific drugs.

A novel FAK-degrading PROTAC molecule exhibited both anti-tumor activities and efficient MDR reversal effects

FAK (focal adhesion kinase) is widely involved in cancer growth and drug resistance development. Thus, FAK inhibition has emerged as an effective strategy for tumor treatment both as a monotherapy or in combination with other treatments. But the current FAK inhibitors mainly concentrate on its kinase activity, overlooking the potential significance of FAK scaffold proteins. In this study we employed the PROTAC technology, and designed a novel PROTAC molecule F2 targeting FAK based on the FAK inhibitor IN10018. F2 exhibited potent inhibitory activities against 4T1, MDA-MB-231, MDA-MB-468 and MDA-MB-435 cells with IC50 values of 0.73, 1.09, 5.84 and 3.05 μM, respectively. On the other hand, F2 also remarkably reversed the multidrug resistance (MDR) in HCT8/T, A549/T and MCF-7/ADR cells. Both the effects of F2 were stronger than the FAK inhibitor IN10018. To our knowledge, F2 was the first reported FAK-targeted PROTAC molecule exhibiting reversing effects on chemotherapeutic drug resistance, and its highest reversal fold could reach 158 times. The anti-tumor and MDR-reversing effects of F2 might be based on its inhibition on AKT (protein kinase B, PKB) and ERK (extracellular signal-regulated kinase) signaling pathways, as well as its impact on EMT (epithelial-mesenchymal transition). Furthermore, we found that F2 could reduce the protein level of P-gp in HCT8/T cells, thereby contributing to reverse drug resistance from another perspective. Our results will boost confidence in future research focusing on targeting FAK and encourage further investigation of PROTAC with potent in vivo effects.

Chemical Composition, Antioxidant Capacity, and Anticancerous Effects against Human Lung Cancer Cells of a Terpenoid-Rich Fraction of Inula viscosa

Inula viscosa is a widely used plant in traditional Mediterranean and Middle Eastern medicine for various illnesses. I. viscosa has been shown to have anticancer effects against various cancers, but its effects against lung cancer have been under limited investigation. At the same time, I. viscosa is rich in terpenoids whose anti-lung cancer effects have been poorly investigated. This study aimed to examine the potential anticancer properties of methanolic and aqueous extracts of stems and leaves of I. viscosa and its terpenoid-rich fraction against human lung cancer A549 cells. Results showed that the methanolic extracts of I. viscosa had significantly higher polyphenol and flavonoid content and radical scavenging capacity than the aqueous extracts. In addition, leaves methanolic extracts (IVLM) caused the highest reduction in viability of A549 cells among all the extracts. IVLM also reduced the viability of human ovarian SK-OV-3, breast MCF-7, liver HepG2, and colorectal HCT116 cancer cells. A terpenoid-rich I. viscosa fraction (IVL DCM), prepared by liquid-liquid separation of IVLM in dichloromethane (DCM), displayed a substantial reduction in the viability of A549 cells (IC50 = 27.8 ± 1.5 µg/mL at 48 h) and the panel of tested cancerous cell lines but was not cytotoxic to normal human embryonic fibroblasts (HDFn). The assessment of IVL DCM phytochemical constituents using GC-MS analysis revealed 21 metabolites, highlighting an enrichment in terpenoids, such as lupeol and its derivatives, caryophyllene oxide, betulin, and isopulegol, known to exhibit proapoptotic and antimetastatic functions. IVL DCM also showed robust antioxidant capacity and decent polyphenol and flavonoid contents. Furthermore, Western blotting analysis indicated that IVL DCM reduced proliferation (reduction of proliferation marker Ki67 and induction of proliferation inhibitor proteins P21 and P27), contaminant with P38 MAP kinase activation, and induced the intrinsic apoptotic pathway (P53/BCL2/BAX/Caspase3/PARP) in A549 cells. IVL DCM also reduced the migration of A549 cells, potentially by reducing FAK activation. Future identification of anticancer metabolites of IVL DCM, especially terpenoids, is recommended. These data place I. viscosa as a new resource of herbal anticancer agents.

Intersecting pathways: The role of hybrid E/M cells and circulating tumor cells in cancer metastasis and drug resistance

Cancer metastasis and therapy resistance are intricately linked with the dynamics of Epithelial-Mesenchymal Transition (EMT) and Circulating Tumor Cells (CTCs). EMT hybrid cells, characterized by a blend of epithelial and mesenchymal traits, have emerged as pivotal in metastasis and demonstrate remarkable plasticity, enabling transitions across cellular states crucial for intravasation, survival in circulation, and extravasation at distal sites. Concurrently, CTCs, which are detached from primary tumors and travel through the bloodstream, are crucial as potential biomarkers for cancer prognosis and therapeutic response. There is a significant interplay between EMT hybrid cells and CTCs, revealing a complex, bidirectional relationship that significantly influences metastatic progression and has a critical role in cancer drug resistance. This resistance is further influenced by the tumor microenvironment, with factors such as tumor-associated macrophages, cancer-associated fibroblasts, and hypoxic conditions driving EMT and contributing to therapeutic resistance. It is important to understand the molecular mechanisms of EMT, characteristics of EMT hybrid cells and CTCs, and their roles in both metastasis and drug resistance. This comprehensive understanding sheds light on the complexities of cancer metastasis and opens avenues for novel diagnostic approaches and targeted therapies and has significant advancements in combating cancer metastasis and overcoming drug resistance.

mTORC2-driven chromatin cGAS mediates chemoresistance through epigenetic reprogramming in colorectal cancer

Cyclic GMP-AMP synthase (cGAS), a cytosolic DNA sensor that initiates a STING-dependent innate immune response, binds tightly to chromatin, where its catalytic activity is inhibited; however, mechanisms underlying cGAS recruitment to chromatin and functions of chromatin-bound cGAS (ccGAS) remain unclear. Here we show that mTORC2-mediated phosphorylation of human cGAS serine 37 promotes its chromatin localization in colorectal cancer cells, regulating cell growth and drug resistance independently of STING. We discovered that ccGAS recruits the SWI/SNF complex at specific chromatin regions, modifying expression of genes linked to glutaminolysis and DNA replication. Although ccGAS depletion inhibited cell growth, it induced chemoresistance to fluorouracil treatment in vitro and in vivo. Moreover, blocking kidney-type glutaminase, a downstream ccGAS target, overcame chemoresistance caused by ccGAS loss. Thus, ccGAS coordinates colorectal cancer plasticity and acquired chemoresistance through epigenetic patterning. Targeting both mTORC2-ccGAS and glutaminase provides a promising strategy to eliminate quiescent resistant cancer cells.

LRRC45 promotes lung cancer proliferation and progression by enhancing c-MYC, slug, MMP2, and MMP9 expression

BACKGROUND

The leucine-rich repeat-containing (LRRC) superfamily members are known for their significant roles in tumorigenesis and cellular proliferation. However, the specific regulatory role of LRRC45 in lung cancer remains unexplored. This study investigated the impact and underlying mechanisms of LRRC45 on the proliferative, migratory, and invasive capacities of lung adenocarcinoma (LUAD) cells, potentially identifying new targets for therapeutic intervention.

MATERIAL AND METHODS

The importance of LRRC45 in lung cancer was analyzed using the online databases of UCSC Xena, TCGA, TISIDB, and UALCAN, whereas to detect target gene expression, we used the qRT-PCR, Western blot, and immunofluorescence confocal. The cell growth was monitored by colony formation assay and migration was examined by cell migration assay. Finally, a xenograft mouse tumor model using A549 ​cells was used to explore the in vivo effect of LRRC45 in lung cancer.

RESULTS

Inhibition of LRRC45 expression led to a notable decrease in proliferation, migration, and invasion of A549 and H1299 ​cells. LRRC45 silencing significantly reduced the tumor volume and improved the mice's survival. Additionally, inhibition of LRRC45 expression dramatically suppressed c-MYC, Slug, MMP2, and MMP9 expression. Overexpression of c-MYC and/or Slug in the LRRC45-deficient cells can partially or totally restore the LRRC45 deficiency-suppressed growth. Moreover, the overexpression of MMP2 and/or MMP9 could partially or totally restore LRRC45 deficiency-reduced cell metastasis.

CONCLUSIONS

LRRC45 could promote the proliferative, migrative, and invasive capacities of lung cancer cells by increasing c-MYC, Slug, MMP2, and MMP9 expression, indicating the therapeutic implications and potential significance of these pathways in lung cancer.

Deciphering cellular and molecular mechanism of MUC13 mucin involved in cancer cell plasticity and drug resistance

There has been a surge of interest in recent years in understanding the intricate mechanisms underlying cancer progression and treatment resistance. One molecule that has recently emerged in these mechanisms is MUC13 mucin, a transmembrane glycoprotein. Researchers have begun to unravel the molecular complexity of MUC13 and its impact on cancer biology. Studies have shown that MUC13 overexpression can disrupt normal cellular polarity, leading to the acquisition of malignant traits. Furthermore, MUC13 has been associated with increased cancer plasticity, allowing cells to undergo epithelial-mesenchymal transition (EMT) and metastasize. Notably, MUC13 has also been implicated in the development of chemoresistance, rendering cancer cells less responsive to traditional treatment options. Understanding the precise role of MUC13 in cellular plasticity, and chemoresistance could pave the way for the development of targeted therapies to combat cancer progression and enhance treatment efficacy.

PP2A B55α inhibits epithelial-mesenchymal transition via regulation of Slug expression in non-small cell lung cancer

PP2A B55α, encoded by PPP2R2A, acts as a regulatory subunit of the serine/threonine phosphatase PP2A. Despite a frequent loss of heterozygosity of PPP2R2A in cases of non-small cell lung cancer (NSCLC), research on PP2A B55α's functions remains limited and controversial. To investigate the biological roles of PP2A B55α, we conducted bulk RNA-sequencing to assess the impact of PPP2R2A knockdown using two shRNAs in a NSCLC cell line. Gene set enrichment analysis (GSEA) of the RNA-sequencing data revealed significant enrichment of the epithelial-mesenchymal transition (EMT) pathway, with SNAI2 (the gene encoding Slug) emerging as one of the top candidates. Our findings demonstrate that PP2A B55α suppresses EMT, as PPP2R2A deficiency through knockdown or homozygous or hemizygous depletion promotes EMT and metastatic behavior in NSCLC cells, as evidenced by changes in EMT biomarkers, invasion and migration abilities, as well as metastasis in a tail vein assay. Mechanistically, PP2A B55α inhibits EMT by downregulating SNAI2 expression via the GSK3β-β-catenin pathway. Importantly, PPP2R2A deficiency also slows cell proliferation by disrupting DNA replication, particularly in PPP2R2A-/- cells. Furthermore, PPP2R2A deficiency, especially PPP2R2A-/- cells, leads to an increase in the cancer stem cell population, which correlates with enhanced resistance to chemotherapy. Overall, the decrease in PP2A B55α levels due to hemizygous/homozygous depletion heightens EMT and the metastatic or stemness/drug resistance potential of NSCLC cells despite their proliferation disadvantage. Our study highlights the significance of PP2A B55α in EMT and metastasis and suggests that targeting EMT/stemness could be a potential therapeutic strategy for treating PPP2R2A-deficient NSCLC.

Clinical applications of circulating biomarkers in non-small cell lung cancer

Despite recent advances in cancer diagnostics and treatment, the mortality associated with lung cancer is still the highest in the world. Late-stage diagnosis, often accompanied by metastasis, is a major contributor to the high mortality rates, emphasizing the urgent need for reliable and readily accessible diagnostic tools that can detect biomarkers unique to lung cancer. Circulating factors, such as circulating tumor DNA and extracellular vesicles, from liquid biopsy have been recognized as diagnostic or prognostic markers in lung cancer. Numerous clinical studies are currently underway to investigate the potential of circulating tumor DNA, circulating tumor RNA, exosomes, and exosomal microRNA within the context of lung cancer. Those clinical studies aim to address the poor diagnostics and limited treatment options for lung cancer, with the ultimate goal of developing clinical markers and personalized therapies. In this review, we discuss the roles of each circulating factor, its current research status, and ongoing clinical studies of circulating factors in non-small cell lung cancer. Additionally, we discuss the circulating factors specifically found in lung cancer stem cells and examine approved diagnostic assays designed to detect circulating biomarkers in lung cancer patients.

Glutamine Metabolism and Prostate Cancer

Glutamine (Gln) is a non-essential amino acid that is involved in the development and progression of several malignancies, including prostate cancer (PCa). While Gln is non-essential for non-malignant prostate epithelial cells, PCa cells become highly dependent on an exogenous source of Gln. The Gln metabolism in PCa is tightly controlled by well-described oncogenes such as MYC, AR, and mTOR. These oncogenes contribute to therapy resistance and progression to the aggressive castration-resistant PCa. Inhibition of Gln catabolism impedes PCa growth, survival, and tumor-initiating potential while sensitizing the cells to radiotherapy. Therefore, given its significant role in tumor growth, targeting Gln metabolism is a promising approach for developing new therapeutic strategies. Ongoing clinical trials evaluate the safety and efficacy of Gln catabolism inhibitors in combination with conventional and targeted therapies in patients with various solid tumors, including PCa. Further understanding of how PCa cells metabolically interact with their microenvironment will facilitate the clinical translation of Gln inhibitors and help improve therapeutic outcomes. This review focuses on the role of Gln in PCa progression and therapy resistance and provides insights into current clinical trials.

Hypermethylated RASAL1's promotive role in chemoresistance and tumorigenesis of choriocarcinoma was regulated by TET2 but not DNMTs

BACKGROUND

Patients with choriocarcinoma (CC) accompanying chemoresistance conventionally present a poor prognosis. Whether ras protein activator like-1 (RASAL1) functions as a tumor promoter or suppressor depends on tumor types. However, the role of RASAL1 in process of chemoresistance of CC and underlying molecular mechanism remain elusive.

METHODS

The expression pattern of RASAL1 in CC cells and tissues was measured using Western blotting, immunohistochemistry and qRT-PCR. Cell viability and proliferative ability were assessed by MTT assay, Tunnel assay and flow cytometric analysis. Additionally, the stemness was evaluated by the colony formation and tumor sphere formation. Methotrexate (MTX) was applied to exam the chemosensitivity of CC cells.

RESULTS

The expression of RASAL1 was reduced both at the protein and mRNA levels in CC tissues and cells compared to hydatidiform mole (HM) and invasive mole (IM). Loss of RASAL1 was attributed to its promoter hypermethylation and could be restored by 5-Aza. Knock-down of RASAL1 promoted the viability, proliferative potential, stemness and EMT phenotype of JEG-3 cells. However, induced overexpression of RASAL1 by 5-Aza significantly prohibited cell proliferation and stemness potential of the JAR cell. Additionally, the xenograft model indicated that knockdown of RASAL1 led to a remarkable increase of tumor volume and weight in comparison with its counterpart. Moreover, the stimulatory activity brought by decrease of RASAL1 could be deprived by β-catenin inhibitor XAV 939, yet the suppressive activity resulted from its promoter demethylation could be rescued by β-catenin activator BML-284, indicating that function of RASAL1 depends on β-catenin. Besides, the co-immunoprecipitation assay confirmed the physical binding between RASAL1 and β-catenin. Further investigations showed hypermethylated RASAL1 was regulated by TET2 but not DNMTs.

CONCLUSION

Taken together, the present data elucidated that reduced RASAL1 through its promoter hypermethylation regulated by TET2 promoted the tumorigenicity and chemoresistance of CC via modulating β-catenin both in vitro and in vivo.

FOXC1 transcriptionally suppresses ABHD5 to inhibit the progression of renal cell carcinoma through AMPK/mTOR pathway

BACKGROUND

Increased activity of the transcription factor FOXC1 leads to elevated transcription of target genes, ultimately facilitating the progression of various cancer types. However, there are currently no literature reports on the role of FOXC1 in renal cell carcinoma.

METHODS

By using RT-qPCR, immunohistochemistry and Western blotting, FOXC1 mRNA and protein expression was evaluated. Gain of function experiments were utilized to assess the proliferation and metastasis ability of cells. A nude mouse model was created for transplanting tumors and establishing a lung metastasis model to observe cell proliferation and spread in a living organism. Various techniques including biological analysis, CHIP assay, luciferase assay, RT-qRCR and Western blotting experiments were utilized to investigate how FOXC1 contributes to the transcription of ABHD5 on a molecular level. FOXC1 was assessed by Western blot for its impact on AMPK/mTOR signaling pathway.

RESULTS

FOXC1 is down-regulated in RCC, causing unfavorable prognosis of patients with RCC. Further experiments showed that forced FOXC1 expression significantly restrains RCC cell growth and cell metastasis. Mechanically, FOXC1 promotes the transcription of ABHD5 to activate AMPK signal pathway to inhibit mTOR signal pathway. Finally, knockdown of ABHD5 recovered the inhibitory role of FOXC1 overexpression induced cell growth and metastasis suppression.

CONCLUSION

In general, our study demonstrates that FOXC1 exerts its tumor suppressor role by promoting ABHD5 transcription to regulating AMPK/mTOR signal pathway. FOXC1 could serve as both a diagnostic indicator and potential treatment focus for RCC.

Kinesin Facilitates Phenotypic Targeting of Therapeutic Resistance in Advanced Prostate Cancer

Understanding the mechanisms underlying resistance is critical to improving therapeutic outcomes in patients with metastatic castration-resistant prostate cancer. Previous work showed that dynamic interconversions between epithelial-mesenchymal transition to mesenchymal-epithelial transition defines the phenotypic landscape of prostate tumors, as a potential driver of the emergence of therapeutic resistance. In this study, we use in vitro and in vivo preclinical MDA PCa patient-derived xenograft models of resistant human prostate cancer to determine molecular mechanisms of cross-resistance between antiandrogen therapy and taxane chemotherapy, underlying the therapeutically resistant phenotype. Transcriptomic profiling revealed that resistant and sensitive prostate cancer C4-2B cells have a unique differential gene signature response to cabazitaxel. Gene pathway analysis showed that sensitive cells exhibit an increase in DNA damage, while resistant cells express genes associated with protein regulation in response to cabazitaxel. The patient-derived xenograft model specimens are from patients who have metastatic lethal castration-resistant prostate cancer, treated with androgen deprivation therapy, antiandrogens, and chemotherapy including second-line taxane chemotherapy, cabazitaxel. Immunohistochemistry revealed high expression of E-cadherin and low expression of vimentin resulting in redifferentiation toward an epithelial phenotype. Furthermore, the mitotic kinesin-related protein involved in microtubule binding and the SLCO1B3 transporter (implicated in cabazitaxel intracellular transport) are associated with resistance in these prostate tumors. Combinational targeting of kinesins (ispinesib) with cabazitaxel was more effective than single monotherapies in inducing cell death in resistant prostate tumors. Implications: Our findings are of translational significance in identifying kinesin as a novel target of cross-resistance toward enhancing therapeutic vulnerability and improved clinical outcomes in patients with advanced prostate cancer.

Biological effect of ETV4 and the underlying mechanism of its regulatory effect on epithelial‑mesenchymal transition in intrahepatic cholangiocarcinoma cells

Intrahepatic cholangiocarcinoma (ICC) is a highly invasive malignant tumor. The prognosis of patients with ICC after radical surgical resection remains poor, due to local infiltration, distant metastasis, a high recurrence rate and lack of effective treatment strategies. E26 transformation-specific sequence variant 4 (ETV4) is a pro-carcinogenic factor that is upregulated in several tumors; however, the role of ETV4 in ICC is relatively unknown. The present study aimed to determine the role of ETV4 in the Hccc9810 ICC cell line and to assess how it contributes to epithelial-mesenchymal transition (EMT) in ICC. Hccc9810 cells were infected with lentiviruses to construct stable ETV4-overexpressing cells, stable ETV4 knockdown cells and corresponding control groups. The Cell Counting Kit-8 and Transwell assays were used to quantify cell proliferation, invasion and migration, and the effects on cell cycle progression and apoptosis were detected by flow cytometry. ETV4 was identified as a driver of cell growth, invasion, migration and cell cycle progression, while restraining apoptosis in Hccc9810 cells. Reverse transcription-quantitative PCR and western blotting revealed that increased ETV4 levels may drive EMT by triggering the TGF-β1/Smad signaling pathway. This cascade, in turn, may foster tumor cell proliferation, migration, invasion and cell cycle advancement, and hinder apoptosis.

Cyanidin inhibits glioma stem cells proliferation through the Wnt signaling pathway

BACKGROUND

Cyanidin has a protective effect on the nervous system and has been reported to treat tumor effectively. However, its impact on glioma stem cells (GSC) is unknown.

METHODS

Using seven GSC lines, the anti-tumor effect of cyanidin is tested. The effect of cyanidin on the cell viability in each cell line is evaluated. Wnt signaling pathway-related genes are checked after treatment of cyanidin. Cytoplasmic/nuclear β-catenin protein levels post cyanidin treatment is detected. Protein levels of c-Myc after cyanidin treatment are determined. Twist1 and Snail1 protein levels after cyanidin treatment are checked as well.

RESULTS

Cyanidin significantly reduces the cell viability of all GSCs, and exhibited the most substantial effect in GBM2 but no apparent effect in 293T cells. It can regulate the Wnt signaling pathway of all GSC lines. In the GBM2, GBM7, G166, and G179 cell lines, there is upregulation of WNT1 and MYC genes, while in the G144 and GliNS2 cell line, these two genes are down-regulated after cyanidin treatment. Cytoplasmic and nuclear protein levels of β-catenin in all cell lines are down-regulated. Cyanidin treatment significantly decreases the protein level for c-Myc in the GBM2 cell line compared with untreated cells, not in G144 or GliNS2 cells. Furthermore, cyanidin strongly reduces the expression of Twist1 and Snail1 in GBM2, G179, and G144 cell lines, while the GliNS2 cells show an opposite change in the cytoplasm and no change in nuclear.

CONCLUSION

Cyanidin exerts an anti-tumor effect in glioma stem cell lines, probably through the Wnt signaling pathway.

Composition, functions, and applications of exosomal membrane proteins

Exosomes play a crucial role in various biological processes, such as human development, immune responses, and disease occurrence. The membrane proteins on exosomes are pivotal factors for their biological functionality. Currently, numerous membrane proteins have been identified on exosome membranes, participating in intercellular communication, mediating target cell recognition, and regulating immune processes. Furthermore, membrane proteins from exosomes derived from cancer cells can serve as relevant biomarkers for early cancer diagnosis. This article provides a comprehensive review of the composition of exosome membrane proteins and their diverse functions in the organism's biological processes. Through in-depth exploration of exosome membrane proteins, it is expected to offer essential foundations for the future development of novel biomedical diagnostics and therapies.

LncRNAs and asymmetric cell division: the epigenetic mechanisms

Asymmetric cell division (ACD) plays a pivotal role in development, tissue homeostasis, and stem cell maintenance. Emerging evidence suggests that long non-coding RNAs (lncRNAs) are key regulators of ACD, orchestrating the intricate molecular machinery that governs cell fate determination. This review summarizes current literature to elucidate the diverse roles of lncRNAs in modulating ACD across various biological contexts. The regulatory mechanisms of asymmetric cell division mediated by lncRNAs, including their interactions with protein effectors, epigenetic regulation, and subcellular localization are explored. Additionally, we discuss the implications of dysregulated lncRNAs in mediating ACD that lead to tumorigenesis. By integrating findings from diverse experimental models and cell types, this review provides insights into the multifaceted roles of lncRNAs in governing asymmetric cell division, shedding light on fundamental biological processes. Further research in this area may lead to the development of novel therapies targeting dysregulated lncRNAs to restore proper cell division and function. The knowledge of lncRNAs regulating ACD could potentially revolutionize the field of regenerative medicine and cancer therapy by targeting specific lncRNAs involved in ACD. By unraveling the complex interactions between lncRNAs and cellular processes, the potential novel opportunities for precision medicine approaches may be uncovered.

TSP50 facilitates breast cancer stem cell-like properties maintenance and epithelial-mesenchymal transition via PI3K p110α mediated activation of AKT signaling pathway

BACKGROUND

Studies have confirmed that epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC)-like properties are conducive to cancer metastasis. In recent years, testes-specific protease 50 (TSP50) has been identified as a prognostic factor and is involved in tumorigenesis regulation. However, the role and molecular mechanisms of TSP50 in EMT and CSC-like properties maintenance remain unclear.

METHODS

The expression and prognostic value of TSP50 in breast cancer were excavated from public databases and explored using bioinformatics analysis. Then the expression of TSP50 and related genes was further validated by quantitative RT-PCR (qRT-PCR), Western blot, and immunohistochemistry (IHC). In order to investigate the function of TSP50 in breast cancer, loss- and gain-of-function experiments were conducted, both in vitro and in vivo. Furthermore, immunofluorescence (IF) and immunoprecipitation (IP) assays were performed to explore the potential molecular mechanisms of TSP50. Finally, the correlation between the expression of TSP50 and related genes in breast cancer tissue microarray and clinicopathological characteristics was analyzed by IHC.

RESULTS

TSP50 was negatively correlated with the prognosis of patients with breast cancer. TSP50 promoted CSC-like traits and EMT in both breast cancer cells and mouse xenograft tumor tissues. Additionally, inhibition of PI3K/AKT partly reversed TSP50-induced activation of CSC-like properties, EMT and tumorigenesis. Mechanistically, TSP50 and PI3K p85α regulatory subunit could competitively interact with the PI3K p110α catalytic subunit to promote p110α enzymatic activity, thereby activating the PI3K/AKT signaling pathway for CSC-like phenotypes maintenance and EMT promotion. Moreover, IHC analysis of human breast cancer specimens revealed that TSP50 expression was positively correlated with p-AKT and ALDH1 protein levels. Notably, breast cancer clinicopathological characteristics, such as patient survival time, tumor size, Ki67, pathologic stage, N stage, estrogen receptor (ER) and progesterone receptor (PR) levels, correlated well with TSP50/p-AKT/ALDH1 expression status.

CONCLUSION

The effects of TSP50 on EMT and CSC-like properties promotion were verified to be dependent on PI3K p110α. Together, our study revealed a novel mechanism by which TSP50 facilitates the progression of breast cancer, which can provide new insights into TSP50-based breast cancer treatment strategies.

Role of Non-coding RNAs in the Response of Glioblastoma to Temozolomide

Chemotherapy and radiotherapy are widely used in clinical practice across the globe as cancer treatments. Intrinsic or acquired chemoresistance poses a significant problem for medical practitioners and researchers, causing tumor recurrence and metastasis. The most dangerous kind of malignant brain tumor is called glioblastoma multiforme (GBM) that often recurs following surgery. The most often used medication for treating GBM is temozolomide chemotherapy; however, most patients eventually become resistant. Researchers are studying preclinical models that accurately reflect human disease and can be used to speed up drug development to overcome chemoresistance in GBM. Non-coding RNAs (ncRNAs) have been shown to be substantial in regulating tumor development and facilitating treatment resistance in several cancers, such as GBM. In this work, we mentioned the mechanisms of how different ncRNAs (microRNAs, long non-coding RNAs, circular RNAs) can regulate temozolomide chemosensitivity in GBM. We also address the role of these ncRNAs encapsulated inside secreted exosomes.

CYR61 confers chemoresistance by upregulating survivin expression in triple-negative breast cancer

Cysteine-rich angiogenic inducer 61 (CYR61) is a protein from the CCN family of matricellular proteins that play diverse regulatory roles in the extracellular matrix. CYR61 is involved in cell adhesion, migration, proliferation, differentiation, apoptosis, and senescence. Here, we show that CYR61 induces chemoresistance in triple-negative breast cancer (TNBC). We observed that CYR61 is overexpressed in TNBC patients, and CYR61 expression correlates negatively with the survival of patients who receive chemotherapy. CYR61 knockdown reduced cell migration, sphere formation and the cancer stem cell (CSC) population and increased the chemosensitivity of TNBC cells. Mechanistically, CYR61 activated Wnt/β-catenin signaling and increased survivin expression, which are associated with chemoresistance, the epithelial-mesenchymal transition, and CSC-like phenotypes. Altogether, our study demonstrates a novel function of CYR61 in chemotherapy resistance in breast cancer.

Assessment and process optimization of high throughput biofabrication of immunocompetent breast cancer model for drug screening applications

Recent advancements in 3D cancer modeling have significantly enhanced our ability to delve into the intricacies of carcinogenesis. Despite the pharmaceutical industry's substantial investment of both capital and time in the drug screening and development pipeline, a concerning trend persists: drug candidates screened on conventional cancer models exhibit a dismal success rate in clinical trials. One pivotal factor contributing to this discrepancy is the absence of drug testing on pathophysiologically biomimetic 3D cancer models during pre-clinical stages. Unfortunately, current manual methods of 3D cancer modeling, such as spheroids and organoids, suffer from limitations in reproducibility and scalability. In our study, we have meticulously developed 3D bioprinted breast cancer model utilizing decellularized adipose tissue-based hydrogel obtained via a detergent-free decellularization method. Our innovative printing techniques allows for rapid, high-throughput fabrication of 3D cancer models in a 96-well plate format, demonstrating unmatched scalability and reproducibility. Moreover, we have conducted extensive validation, showcasing the efficacy of our platform through drug screening assays involving two potent anti-cancer drugs, 5-Fluorouracil and PRIMA-1Met. Notably, our platform facilitates effortless imaging and gene expression analysis, streamlining the evaluation process. In a bid to enhance the relevance of our cancer model, we have introduced a heterogeneous cell population into the DAT-based bioink. Through meticulous optimization and characterization, we have successfully developed a biomimetic immunocompetent breast cancer model, complete with microenvironmental cues and diverse cell populations. This breakthrough paves the way for rapid multiplex drug screening and the development of personalized cancer models, marking a paradigm shift in cancer research and pharmaceutical development.

Automated Analysis of Extracellular Matrix Invasion of Cancer Cells from Tumor Spheroids

The main cause of mortality among cancer patients is metastatic disease. Metastasis develops from cancer cells that invade the stromal tissue and intravasate the circulatory or lymphatic systems to eventually form new tumors in other organs. Blocking cancer cell invasion can potentially prevent or reduce the metastatic progression of cancers. Testing different chemical compounds against cell invasion in three-dimensional cultures is a common laboratory technique. The efficacy of the treatments is often evaluated from confocal microscopic images of the cells using image processing. However, the analysis approaches are often subject to variations and inconsistencies due to user decisions that must be made while processing each image. To overcome this limitation, we developed a fully automated method to quantify the invasion of cancer cells from a 3D tumor spheroid into the surrounding extracellular matrix. We demonstrated that this method resolves cell invasion from spheroids of different shapes and sizes and from cells that invade as a cluster or individually. We also showed that this approach can help quantify the dose-dependent anti-invasive effects of a commonly used chemotherapy drug. Our automated method significantly reduces the time and increases the consistency and accuracy of cancer cell invasion analysis in three-dimensional cultures.

The Antioxidant Potential and Anticancer Activity of Halodule uninervis Ethanolic Extract against Triple-Negative Breast Cancer Cells

Natural remedies have been indispensable to traditional medicine practices for generations, offering therapeutic solutions for various ailments. In modern times, these natural products continue to play a pivotal role in the discovery of new drugs, especially for cancer treatment. The marine ecosystem offers a wide range of plants with potential anticancer activities due to their distinct biochemical diversity and adaptation to extreme situations. The seagrass Halodule uninervis is rich in diverse bioactive metabolites that bestow the plant with various pharmacological properties. However, its anticancer activity against invasive triple-negative breast cancer (TNBC) is still poorly investigated. In the present study, the phytochemical composition of an ethanolic extract of H. uninervis (HUE) was screened, and its antioxidant potential was evaluated. Moreover, the anticancer potential of HUE against MDA-MB-231 cells was investigated along with the possible underlying mechanisms of action. Our results showed that HUE is rich in diverse phytochemicals that are known for their antioxidant and anticancer effects. In MDA-MB-231 cells, HUE targeted the hallmarks of cancer, including cell proliferation, adhesion, migration, invasion, and angiogenesis. The HUE-mediated anti-proliferative and anti-metastatic effects were associated with the downregulation of the proto-oncogenic STAT3 signaling pathway. Taken together, H. uninervis could serve as a valuable source for developing novel drugs targeting TNBC.

From Inflammation to Oncogenesis: Tracing Serum DCLK1 and miRNA Signatures in Chronic Liver Diseases

Chronic liver diseases, fibrosis, cirrhosis, and HCC are often a consequence of persistent inflammation. However, the transition mechanisms from a normal liver to fibrosis, then cirrhosis, and further to HCC are not well understood. This study focused on the role of the tumor stem cell protein doublecortin-like kinase 1 (DCLK1) in the modulation of molecular factors in fibrosis, cirrhosis, or HCC. Serum samples from patients with hepatic fibrosis, cirrhosis, and HCC were analyzed via ELISA or NextGen sequencing and were compared with control samples. Differentially expressed (DE) microRNAs (miRNA) identified from these patient sera were correlated with DCLK1 expression. We observed elevated serum DCLK1 levels in fibrosis, cirrhosis, and HCC patients; however, TGF-β levels were only elevated in fibrosis and cirrhosis. While DE miRNAs were identified for all three disease states, miR-12136 was elevated in fibrosis but was significantly increased further in cirrhosis. Additionally, miR-1246 and miR-184 were upregulated when DCLK1 was high, while miR-206 was downregulated. This work distinguishes DCLK1 and miRNAs' potential role in different axes promoting inflammation to tumor progression and may serve to identify biomarkers for tracking the progression from pre-neoplastic states to HCC in chronic liver disease patients as well as provide targets for treatment.

Targeting the glutamine metabolism to suppress cell proliferation in mesenchymal docetaxel-resistant prostate cancer

Docetaxel (DX) serves as a palliative treatment option for metastatic prostate cancer (PCa). Despite initial remission, acquired DX resistance is inevitable. The mechanisms behind DX resistance have not yet been deciphered, but a mesenchymal phenotype is associated with DX resistance. Mesenchymal phenotypes have been linked to metabolic rewiring, obtaining most ATP production by oxidative phosphorylation (OXPHOS) powered substantially by glutamine (Gln). Likewise, Gln is known to play an essential role in modulating bioenergetic, redox homeostasis and autophagy. Herein, investigations of Gln deprivation on DX-sensitive and -resistant (DR) PCa cells revealed that the DR cell sub-lines were susceptible to Gln deprivation. Mechanistically, Gln deprivation reduced OXPHOS and ATP levels, causing a disturbance in cell cycle progression. Genetic and chemical inhibition of the Gln-metabolism key protein GLS1 could validate the Gln deprivation results, thereby representing a valid therapeutic target. Moreover, immunohistological investigation of GLS1 revealed a high-expressing GLS1 subgroup post-docetaxel failure, exhibiting low overall survival. This subgroup presents an intriguing opportunity for targeted therapy focusing on glutamine metabolism. Thus, these findings highlight a possible clinical rationale for the chemical inhibition of GLS1 as a therapeutic strategy to target mesenchymal DR PCa cells, thereby delaying accelerated tumour progression.

Cetuximab chemotherapy resistance: Insight into the homeostatic evolution of head and neck cancer (Review)

The complex evolution of genetic alterations in cancer that occurs in vivo is a selective process involving numerous factors and mechanisms. Chemotherapeutic agents that prevent the growth and spread of cancer cells induce selective pressure, leading to rapid artificial selection of resistant subclones. This rapid evolution is possible because antineoplastic drugs promote alterations in tumor‑cell metabolism, thus creating a bottleneck event. The few resistant cells that survive in this new environment obtain differential reproductive success that enables them to pass down the newly selected resistant gene pool. The present review aims to summarize key findings of tumor evolution, epithelial‑mesenchymal transition and resistance to cetuximab therapy in head and neck squamous cell carcinoma.

Alternative splicing in EMT and TGF-β signaling during cancer progression

Epithelial to mesenchymal transition (EMT) is a physiological process during development where epithelial cells transform to acquire mesenchymal characteristics, which allows them to migrate and colonize secondary tissues. Many cellular signaling pathways and master transcriptional factors exert a myriad of controls to fine tune this vital process to meet various developmental and physiological needs. Adding to the complexity of this network are post-transcriptional and post-translational regulations. Among them, alternative splicing has been shown to play important roles to drive EMT-associated phenotypic changes, including actin cytoskeleton remodeling, cell-cell junction changes, cell motility and invasiveness. In advanced cancers, transforming growth factor-β (TGF-β) is a major inducer of EMT and is associated with tumor cell metastasis, cancer stem cell self-renewal, and drug resistance. This review aims to provide an overview of recent discoveries regarding alternative splicing events and the involvement of splicing factors in the EMT and TGF-β signaling. It will emphasize the importance of various splicing factors involved in EMT and explore their regulatory mechanisms.

Isolation and phenotypic characterization of cancer stem cells from metastatic oral cancer cells

OBJECTIVES

To isolate cancer stem cells (CSC) from a metastatic oral squamous cell carcinoma (OSCC) cell line and investigate their in vitro and in vivo phenotypic characteristics.

MATERIALS AND METHODS

Subpopulations with individual staining intensities for CD44 and CD326 were isolated from the OSCC cell line LN-1A by FACS: CD44Low/CD326- (CSC-M1), CD44Low/CD326High (CSC-E), and CD44High/CD326- (CSC-M2). Proliferation, clonogenic potential, adhesion, migration, epithelial-mesenchymal transition markers, and sensitivity to cisplatin and TVB-3166 were analyzed in vitro. Tumor formation and metastasis were assessed by subcutaneous and orthotopic inoculations into BALB/c mice.

RESULTS

E-cadherin levels were higher in CSC-E cells while vimentin and Slug more produced by CSC-M2 cells. CSC-M1 and CSC-M2 subpopulations showed higher proliferation, produced more colonies, and have stronger adhesion to the extracellular matrix. All cell lines established tumors; however, CSC-E and CSC-M2 formed larger masses and produced more metastases.

CONCLUSION

The CSC subpopulations here described show increased cancer capabilities in vitro, tumorigenic and metastatic potential in vivo, and may be exploited in the search for novel therapeutic targets for OSCC.

Exploring the mystery of colon cancer from the perspective of molecular subtypes and treatment

The molecular categorization of colon cancer patients remains elusive. Gene set enrichment analysis (GSEA), which investigates the dysregulated genes among tumor and normal samples, has revealed the pivotal role of epithelial-to-mesenchymal transition (EMT) in colon cancer pathogenesis. In this study, we employed multi-clustering method for grouping data, resulting in the identification of two clusters characterized by varying prognostic outcomes. These two subgroups not only displayed disparities in overall survival (OS) but also manifested variations in clinical variables, genetic mutation, and gene expression profiles. Using the nearest template prediction (NTP) method, we were able to replicate the molecular classification effectively within the original dataset and validated it across multiple independent datasets, underscoring its robust repeatability. Furthermore, we constructed two prognostic signatures tailored to each of these subgroups. Our molecular classification, centered on EMT, hold promise in offering fresh insights into the therapy strategies and prognosis assessment for colon cancer.

Mesencephalic astrocyte-derived neurotrophic factor inhibits cervical cancer progression via regulating macrophage phenotype

BACKGROUND

Cervical cancer is a common gynecologic malignant tumor, but the critical factors affecting cervical cancer progression are still not well demonstrated. Mesencephalic astrocyte-derived neurotrophic factor (MANF) has been widely recognized as an anti-inflammatory factor to regulate macrophage polarization. In this study, the effect and mechanism of MANF on cervical cancer were preliminarily explored.

METHODS AND RESULTS

Kaplan-Meier curve was used to show the overall survival time of the involved cervical cancer patients with high and low MANF expression in cervical cancer tissues. MANF was highly expressed in peritumoral tissues of cervical carcinoma by using immunohistochemistry and western blot. MANF mRNA level was detected by using qRT-PCR. Dual-labeled immunofluorescence showed MANF was mainly expressed in macrophages of cervical peritumoral tissues. Moreover, MANF-silenced macrophages promoted HeLa and SiHa cells survival, migration, invasion and EMT via NF-κB signaling activation. The results of tumor formation in nude mice indicated MANF-silenced macrophages promoted cervical tumor formation in vivo.

CONCLUSION

Our study reveals an inhibitory role of MANF in cervical cancer progression, indicating MANF as a new and valuable therapeutic target for cervical cancer treatment.

miR-497/195 Cluster Affects the Development of Colorectal Cancer by Targeting FRA1

The miR-497-195 cluster facilitates the occurrence and development of cancer. This study aims to investigate whether the miR-195-497 cluster could regulate the progression of colorectal cancer by regulating the common target gene, FOS-related antigen 1 (FRA1). Overexpression of the miR-195/497 vector was used to evaluate the effect of overexpression of miR-195-497 clusters on the biological behavior of colon cancer cells. In animal experiments, tumor growth and metastasis were recorded by constructing a nude mouse model of a subcutaneously implanted tumor. miR-195 and miR-497 were expressed to varying degrees in Caco-2, LoVo, and HT-29 cells. Overexpression of miR-195/497 and inhibition of FRA1 decreased HT-29 cell proliferation, inhibited cell invasion and migration, and promoted Epithelial-mesenchymal transition (EMT). In vivo experiments showed that the overexpression of miR-195/497 or inhibition of FRA1 inhibited tumor growth, affected EMT in tumor cells, and inhibited the expression of FRA1. Additionally, the aforementioned conditions had the best effect when used together. The miR-195-497 cluster can regulate the proliferation, EMT, invasion, and migration of colorectal cancer cells by regulating the common target gene FRA1, thereby affecting the development of colorectal cancer.

Ago2/CAV1 interaction potentiates metastasis via controlling Ago2 localization and miRNA action

Ago2 differentially regulates oncogenic and tumor-suppressive miRNAs in cancer cells. This discrepancy suggests a secondary event regulating Ago2/miRNA action in a context-dependent manner. We show here that a positive charge of Ago2 K212, that is preserved by SIR2-mediated Ago2 deacetylation in cancer cells, is responsible for the direct interaction between Ago2 and Caveolin-1 (CAV1). Through this interaction, CAV1 sequesters Ago2 on the plasma membranes and regulates miRNA-mediated translational repression in a compartment-dependent manner. Ago2/CAV1 interaction plays a role in miRNA-mediated mRNA suppression and in miRNA release via extracellular vesicles (EVs) from tumors into the circulation, which can be used as a biomarker of tumor progression. Increased Ago2/CAV1 interaction with tumor progression promotes aggressive cancer behaviors, including metastasis. Ago2/CAV1 interaction acts as a secondary event in miRNA-mediated suppression and increases the complexity of miRNA actions in cancer.

Exploiting transcription factors to target EMT and cancer stem cells for tumor modulation and therapy

Transcription factors (TFs) are essential in controlling gene regulatory networks that determine cellular fate during embryogenesis and tumor development. TFs are the major players in promoting cancer stemness by regulating the function of cancer stem cells (CSCs). Understanding how TFs interact with their downstream targets for determining cell fate during embryogenesis and tumor development is a critical area of research. CSCs are increasingly recognized for their significance in tumorigenesis and patient prognosis, as they play a significant role in cancer initiation, progression, metastasis, and treatment resistance. However, traditional therapies have limited effectiveness in eliminating this subset of cells, allowing CSCs to persist and potentially form secondary tumors. Recent studies have revealed that cancer cells and tumors with CSC-like features also exhibit genes related to the epithelial-to-mesenchymal transition (EMT). EMT-associated transcription factors (EMT-TFs) like TWIST and Snail/Slug can upregulate EMT-related genes and reprogram cancer cells into a stem-like phenotype. Importantly, the regulation of EMT-TFs, particularly through post-translational modifications (PTMs), plays a significant role in cancer metastasis and the acquisition of stem cell-like features. PTMs, including phosphorylation, ubiquitination, and SUMOylation, can alter the stability, localization, and activity of EMT-TFs, thereby modulating their ability to drive EMT and stemness properties in cancer cells. Although targeting EMT-TFs holds potential in tackling CSCs, current pharmacological approaches to do so directly are unavailable. Therefore, this review aims to explore the role of EMT- and CSC-TFs, their connection and impact in cellular development and cancer, emphasizing the potential of TF networks as targets for therapeutic intervention.

Peristromal niches protect lung cancers from targeted therapies through a combined effect of multiple molecular mediators

Targeted therapies directed against oncogenic signaling addictions, such as inhibitors of ALK in ALK+ NSCLC often induce strong and durable clinical responses. However, they are not curative in metastatic cancers, as some tumor cells persist through therapy, eventually developing resistance. Therapy sensitivity can reflect not only cell-intrinsic mechanisms but also inputs from stromal microenvironment. Yet, the contribution of tumor stroma to therapeutic responses in vivo remains poorly defined. To address this gap of knowledge, we assessed the contribution of stroma-mediated resistance to therapeutic responses to the frontline ALK inhibitor alectinib in xenograft models of ALK+ NSCLC. We found that stroma-proximal tumor cells are partially protected against cytostatic effects of alectinib. This effect is observed not only in remission, but also during relapse, indicating the strong contribution of stroma-mediated resistance to both persistence and resistance. This therapy-protective effect of the stromal niche reflects a combined action of multiple mechanisms, including growth factors and extracellular matrix components. Consequently, despite improving alectinib responses, suppression of any individual resistance mechanism was insufficient to fully overcome the protective effect of stroma. Focusing on shared collateral sensitivity of persisters offered a superior therapeutic benefit, especially when using an antibody-drug conjugate with bystander effect to limit therapeutic escape. These findings indicate that stroma-mediated resistance might be the major contributor to both residual and progressing disease and highlight the limitation of focusing on suppressing a single resistance mechanism at a time.

Advances and Challenges in Targeting TGF-β Isoforms for Therapeutic Intervention of Cancer: A Mechanism-Based Perspective

The TGF-β family is a group of 25 kDa secretory cytokines, in mammals consisting of three dimeric isoforms (TGF-βs 1, 2, and 3), each encoded on a separate gene with unique regulatory elements. Each isoform plays unique, diverse, and pivotal roles in cell growth, survival, immune response, and differentiation. However, many researchers in the TGF-β field often mistakenly assume a uniform functionality among all three isoforms. Although TGF-βs are essential for normal development and many cellular and physiological processes, their dysregulated expression contributes significantly to various diseases. Notably, they drive conditions like fibrosis and tumor metastasis/progression. To counter these pathologies, extensive efforts have been directed towards targeting TGF-βs, resulting in the development of a range of TGF-β inhibitors. Despite some clinical success, these agents have yet to reach their full potential in the treatment of cancers. A significant challenge rests in effectively targeting TGF-βs' pathological functions while preserving their physiological roles. Many existing approaches collectively target all three isoforms, failing to target just the specific deregulated ones. Additionally, most strategies tackle the entire TGF-β signaling pathway instead of focusing on disease-specific components or preferentially targeting tumors. This review gives a unique historical overview of the TGF-β field often missed in other reviews and provides a current landscape of TGF-β research, emphasizing isoform-specific functions and disease implications. The review then delves into ongoing therapeutic strategies in cancer, stressing the need for more tools that target specific isoforms and disease-related pathway components, advocating mechanism-based and refined approaches to enhance the effectiveness of TGF-β-targeted cancer therapies.

Understanding the Role of Connexins in Hepatocellular Carcinoma: Molecular and Prognostic Implications

Connexins, a family of tetraspan membrane proteins forming intercellular channels localized in gap junctions, play a pivotal role at the different stages of tumor progression presenting both pro- and anti-tumorigenic effects. Considering the potential role of connexins as tumor suppressors through multiple channel-independent mechanisms, their loss of expression may be associated with tumorigenic activity, while it is hypothesized that connexins favor the clonal expansion of tumor cells and promote cell migration, invasion, and proliferation, affecting metastasis and chemoresistance in some cases. Hepatocellular carcinoma (HCC), characterized by unfavorable prognosis and limited responsiveness to current therapeutic strategies, has been linked to gap junction proteins as tumorigenic factors with prognostic value. Notably, several members of connexins have emerged as promising markers for assessing the progression and aggressiveness of HCC, as well as the chemosensitivity and radiosensitivity of hepatocellular tumor cells. Our review sheds light on the multifaceted role of connexins in HCC pathogenesis, offering valuable insights on recent advances in determining their prognostic and therapeutic potential.

Tumor Microenvironment Modulation by Cancer-Derived Extracellular Vesicles

The tumor microenvironment (TME) plays an important role in the process of tumorigenesis, regulating the growth, metabolism, proliferation, and invasion of cancer cells, as well as contributing to tumor resistance to the conventional chemoradiotherapies. Several types of cells with relatively stable phenotypes have been identified within the TME, including cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), neutrophils, and natural killer (NK) cells, which have been shown to modulate cancer cell proliferation, metastasis, and interaction with the immune system, thus promoting tumor heterogeneity. Growing evidence suggests that tumor-cell-derived extracellular vesicles (EVs), via the transfer of various molecules (e.g., RNA, proteins, peptides, and lipids), play a pivotal role in the transformation of normal cells in the TME into their tumor-associated protumorigenic counterparts. This review article focuses on the functions of EVs in the modulation of the TME with a view to how exosomes contribute to the transformation of normal cells, as well as their importance for cancer diagnosis and therapy.

Three-Dimensional Tumor Models to Study Cancer Stemness-Mediated Drug Resistance

Solid tumors often contain genetically different populations of cancer cells, stromal cells, various structural and soluble proteins, and other soluble signaling molecules. The American Cancer society estimated 1,958,310 new cancer cases and 609,820 cancer deaths in the United States in 2023. A major barrier against successful treatment of cancer patients is drug resistance. Gain of stem cell-like states by cancer cells under drug pressure or due to interactions with the tumor microenvironment is a major mechanism that renders therapies ineffective. Identifying approaches to target cancer stem cells is expected to improve treatment outcomes for patients. Most of our understanding of drug resistance and the role of cancer stemness is from monolayer cell cultures. Recent advances in cell culture technologies have enabled developing sophisticated three-dimensional tumor models that facilitate mechanistic studies of cancer drug resistance. This review summarizes the role of cancer stemness in drug resistance and highlights the various tumor models that are used to discover the underlying mechanisms and test potentially novel therapeutics.

Combinatorial Cooperativity in miR200-Zeb Feedback Network can Control Epithelial-Mesenchymal Transition

Carcinomas often utilize epithelial-mesenchymal transition (EMT) programs for cancer progression and metastasis. Numerous studies report SNAIL-induced miR200/Zeb feedback circuit as crucial in regulating EMT by placing cancer cells in at least three phenotypic states, viz. epithelial (E), hybrid (h-E/M), mesenchymal (M), along the E-M phenotypic spectrum. However, a coherent molecular-level understanding of how such a tiny circuit controls carcinoma cell entrance into and residence in various states is lacking. Here, we use molecular binding data and mathematical modeling to report that the miR200/Zeb circuit can essentially utilize combinatorial cooperativity to control E-M phenotypic plasticity. We identify minimal combinatorial cooperativities that give rise to E, h-E/M, and M phenotypes. We show that disrupting a specific number of miR200 binding sites on Zeb as well as Zeb binding sites on miR200 can have phenotypic consequences-the circuit can dynamically switch between two (E, M) and three (E, h-E/M, M) phenotypes. Further, we report that in both SNAIL-induced and SNAIL knock-out miR200/Zeb circuits, cooperative transcriptional feedback on Zeb as well as Zeb translation inhibition due to miR200 are essential for the occurrence of intermediate h-E/M phenotype. Finally, we demonstrate that SNAIL can be dispensable for EMT, and in the absence of SNAIL, the transcriptional feedback can control cell state transition from E to h-E/M, to M state. Our results thus highlight molecular-level regulation of EMT in miR200/Zeb circuit and we expect these findings to be crucial to future efforts aiming to prevent EMT-facilitated dissemination of carcinomas.

Shrimp Lipids Inhibit Migration, Epithelial-Mesenchymal Transition, and Cancer Stem Cells via Akt/mTOR/c-Myc Pathway Suppression

Shrimp is a rich source of bioactive molecules that provide health benefits. However, the high cholesterol content in shrimp oil may pose a risk. We utilized the cholesterol elimination method to obtain cholesterol-free shrimp lipids (CLs) and investigated their anticancer potential, focusing on cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT). Our study focused on CSCs and EMT, as these factors are known to contribute to cancer metastasis. The results showed that treatment with CLs at doses ranging from 0 to 500 µg/mL significantly suppressed the cell migration ability of human lung cancer (H460 and H292) cells, indicating its potential to inhibit cancer metastasis. The CLs at such concentrations did not cause cytotoxicity to normal human keratinocytes. Additionally, CL treatment was found to significantly reduce the levels of Snail, Slug, and Vimentin, which are markers of EMT. Furthermore, we investigated the effect of CLs on CSC-like phenotypes and found that CLs could significantly suppress the formation of a three-dimensional (3D) tumor spheroid in lung cancer cells. Furthermore, CLs induced apoptosis in the CSC-rich population and significantly depleted the levels of CSC markers CD133, CD44, and Sox2. A mechanistic investigation demonstrated that exposing lung cancer cells to CLs downregulated the phosphorylation of Akt and mTOR, as well as c-Myc expression. Based on these findings, we believe that CLs may have beneficial effects on health as they potentially suppress EMT and CSCs, as well as the cancer-potentiating pathway of Akt/mTOR/c-Myc.

Nanomedicine as a multimodal therapeutic paradigm against cancer: on the way forward in advancing precision therapy

Recent years have witnessed dramatic improvements in nanotechnology-based cancer therapeutics, and it continues to evolve from the use of conventional therapies (chemotherapy, surgery, and radiotherapy) to increasingly multi-complex approaches incorporating thermal energy-based tumor ablation (e.g. magnetic hyperthermia and photothermal therapy), dynamic therapy (e.g. photodynamic therapy), gene therapy, sonodynamic therapy (e.g. ultrasound), immunotherapy, and more recently real-time treatment efficacy monitoring (e.g. theranostic MRI-sensitive nanoparticles). Unlike monotherapy, these multimodal therapies (bimodal, i.e., a combination of two therapies, and trimodal, i.e., a combination of more than two therapies) incorporating nanoplatforms have tremendous potential to improve the tumor tissue penetration and retention of therapeutic agents through selective active/passive targeting effects. These combinatorial therapies can correspondingly alleviate drug response against hypoxic/acidic and immunosuppressive tumor microenvironments and promote/induce tumor cell death through various multi-mechanisms such as apoptosis, autophagy, and reactive oxygen-based cytotoxicity, e.g., ferroptosis, etc. These multi-faced approaches such as targeting the tumor vasculature, neoangiogenic vessels, drug-resistant cancer stem cells (CSCs), preventing intra/extravasation to reduce metastatic growth, and modulation of antitumor immune responses work complementary to each other, enhancing treatment efficacy. In this review, we discuss recent advances in different nanotechnology-mediated synergistic/additive combination therapies, emphasizing their underlying mechanisms for improving cancer prognosis and survival outcomes. Additionally, significant challenges such as CSCs, hypoxia, immunosuppression, and distant/local metastasis associated with therapy resistance and tumor recurrences are reviewed. Furthermore, to improve the clinical precision of these multimodal nanoplatforms in cancer treatment, their successful bench-to-clinic translation with controlled and localized drug-release kinetics, maximizing the therapeutic window while addressing safety and regulatory concerns are discussed. As we advance further, exploiting these strategies in clinically more relevant models such as patient-derived xenografts and 3D organoids will pave the way for the application of precision therapy.

Insights into lenvatinib resistance: mechanisms, potential biomarkers, and strategies to enhance sensitivity

Lenvatinib is a multitargeted tyrosine kinase inhibitor capable of promoting apoptosis, suppressing angiogenesis, inhibiting tumor cell proliferation, and modulating the immune response. In multiple cancer types, lenvatinib has presented manageable safety and is currently approved as an effective first-line therapy. However, with the gradual increase in lenvatinib application, the inevitable progression of resistance to lenvatinib is becoming more prevalent. A series of recent researches have reported the mechanisms underlying the development of lenvatinib resistance in tumor therapy, which are related to the regulation of cell death or proliferation, histological transformation, metabolism, transport processes, and epigenetics. In this review, we aim to outline recent discoveries achieved in terms of the mechanisms and potential predictive biomarkers of lenvatinib resistance as well as to summarize untapped approaches available for improving the therapeutic efficacy of lenvatinib in patients with various types of cancers.

Plasticity-induced repression of Irf6 underlies acquired resistance to cancer immunotherapy in pancreatic ductal adenocarcinoma

Acquired resistance to immunotherapy remains a critical yet incompletely understood biological mechanism. Here, using a mouse model of pancreatic ductal adenocarcinoma (PDAC) to study tumor relapse following immunotherapy-induced responses, we find that resistance is reproducibly associated with an epithelial-to-mesenchymal transition (EMT), with EMT-transcription factors ZEB1 and SNAIL functioning as master genetic and epigenetic regulators of this effect. Acquired resistance in this model is not due to immunosuppression in the tumor immune microenvironment, disruptions in the antigen presentation machinery, or altered expression of immune checkpoints. Rather, resistance is due to a tumor cell-intrinsic defect in T-cell killing. Molecularly, EMT leads to the epigenetic and transcriptional silencing of interferon regulatory factor 6 (Irf6), rendering tumor cells less sensitive to the pro-apoptotic effects of TNF-α. These findings indicate that acquired resistance to immunotherapy may be mediated by programs distinct from those governing primary resistance, including plasticity programs that render tumor cells impervious to T-cell killing.

Fractionation and phytochemical composition of an ethanolic extract of Ziziphus nummularia leaves: antioxidant and anticancerous properties in human triple negative breast cancer cells

Natural products have long been utilized in traditional medicine as remedies to improve health and treat illnesses, and have had a key role in modern drug discovery. Recently, there has been a revived interest in the search for bioactives from natural sources as alternative or complementary modalities to synthetic medicines; especially for cancer treatment, which incidence and mortality rates are on the rise worldwide. Ziziphus nummularia has been widely used in traditional medicine for the treatment of various diseases. Its traditional uses and numerous ethnopharmacological properties may be attributed to its richness in bioactive metabolites. However, its phytochemical composition or chemopreventive effects against the aggressive triple-negative breast cancer (TNBC) are still poorly explored. Here, phytochemical composition of an ethanolic extract of Z. nummularia leaves (ZNE) and its chromatographically isolated fractions was identified both qualitatively by spectrophotometric assays and analytically by HPLC-PDA-MS/MS. The anti-proliferative effects of ZNE were tested in several cancer cell lines, but we focused on its anti-TNBC effects since they were not explored yet. The anti-cancerous potential of ZNE and its fractions was tested in vitro in MDA-MB-231, a TNBC cell line. Results showed that ZNE and its Fraction 6 (F6) reduced the viability of MDA-MB-231 cells. F6 decreased MDA-MB-231 viability more than crude ZNE or its other fractions. ZNE and F6 are rich in phytochemicals and HPLC-PDA-MS/MS analysis identified several metabolites that were previously reported to have anti-cancerous effects. Both ZNE and F6 showed potent antioxidant capacity in the DPPH assay, but promoted reactive oxygen species (ROS) production in MDA-MB-231 cells; an effect which was blunted by the antioxidant N-acetyl cysteine (NAC). NAC also blunted ZNE- and F6-induced reduction in TNBC cell viability. We also demonstrated that ZNE and F6 induced an arrest of the cell cycle, and triggered apoptosis- and autophagy-mediated cell death. ZNE and F6 inhibited metastasis-related cellular processes by modifying cell migration, invasion, and adhesion. Taken together, our findings reveal that Z. nummularia is rich in phytochemicals that can attenuate the malignant phenotype of TNBC and may offer innovative avenues for the discovery of new drug leads for treatment of TNBC and other cancers.

Terpenoid-Mediated Targeting of STAT3 Signaling in Cancer: An Overview of Preclinical Studies

Cancer has become one of the most multifaceted and widespread illnesses affecting human health, causing substantial mortality at an alarming rate. After cardiovascular problems, the condition has a high occurrence rate and ranks second in terms of mortality. The development of new drugs has been facilitated by increased research and a deeper understanding of the mechanisms behind the emergence and advancement of the disease. Numerous preclinical and clinical studies have repeatedly demonstrated the protective effects of natural terpenoids against a range of malignancies. Numerous potential bioactive terpenoids have been investigated in natural sources for their chemopreventive and chemoprotective properties. In practically all body cells, the signaling molecule referred to as signal transducer and activator of transcription 3 (STAT3) is widely expressed. Numerous studies have demonstrated that STAT3 regulates its downstream target genes, including Bcl-2, Bcl-xL, cyclin D1, c-Myc, and survivin, to promote the growth of cells, differentiation, cell cycle progression, angiogenesis, and immune suppression in addition to chemotherapy resistance. Researchers viewed STAT3 as a primary target for cancer therapy because of its crucial involvement in cancer formation. This therapy primarily focuses on directly and indirectly preventing the expression of STAT3 in tumor cells. By explicitly targeting STAT3 in both in vitro and in vivo settings, it has been possible to explain the protective effect of terpenoids against malignant cells. In this study, we provide a complete overview of STAT3 signal transduction processes, the involvement of STAT3 in carcinogenesis, and mechanisms related to STAT3 persistent activation. The article also thoroughly summarizes the inhibition of STAT3 signaling by certain terpenoid phytochemicals, which have demonstrated strong efficacy in several preclinical cancer models.