Inhibition of autophagy by chloroquine prevents resistance to PI3K/AKT inhibitors and potentiates their antitumor effect in combination with paclitaxel in triple negative breast cancer models

Alpha lipoic acid modulates metabolic reprogramming in breast cancer stem cells enriched 3D spheroids by targeting phosphoinositide 3-kinase: In silico and in vitro insights

Breast cancer stem cells (BCSCs) are a unique subpopulation of tumor cells driving tumor resistance, progression, metastasis, and recurrence. Reprogrammed cellular metabolism and key signaling pathways, including Wnt/β-catenin, TGF-β, STAT3, and PI3K/AKT/mTOR pathway play a vital role in maintaining BCSCs. Importantly, PI3K/Akt/mTOR pathway regulates metabolism, survival, growth, and invasion, with PIK3CA, encoding the PI3K catalytic subunit p110α, the most frequently mutated gene in breast cancer. This study investigates the effects of alpha-lipoic acid (LA) on the metabolic profile of BCSCs, focusing on its interaction with PI3K signaling. LA was found to bind PI3K, disrupting cancer-associated metabolic pathways and significantly inhibiting BCSC metabolism. Metabolomic analysis of MCF-7 and MDA-MB-231-derived breast cancer spheroids showed LA-induced metabolic shifts. In MCF-7 spheroids, LA induced upaccumulation of 15 metabolites and downaccumulation of 5, while in MDA-MB-231 spheroids, it induced upaccumulation of 3 and downaccumulation of 16. LA also enhanced the sensitivity of breast cancer spheroids to doxorubicin (Dox), demonstrating a synergistic effect. Mechanistically, LA modulates the PI3K/Akt/mTOR pathway, impairing cell survival and proliferation. These findings highlight the potential of LA as a therapeutic agent for reprogramming cancer metabolism and enhancing chemotherapy efficacy. These results provide a strong rationale for incorporating LA into combination therapy strategies for breast cancer treatment.

RIP2/NF-κB/PD-L1 signaling pathway is involved in temozolomide resistance by inducing autophagy in glioblastoma cells

Autophagy is an important factor in temozolomide (TMZ) resistance in glioblastoma (GBM). Receptor-interacting protein 2 (RIP2) is associated with autophagy, but its role and mechanism in regulating autophagy in GBM cells remain unclear. To analyze RIP2 expression in GBM in The Cancer Genome Atlas (TCGA) dataset. GBM cells were stimulated using recombinant human RIP2 protein (rRIP2) or RIP2 plasmid. Cell proliferation and apoptosis were assessed using CCK-8 assay and flow cytometry. Western blotting and immunofluorescence (IF) assays were performed to detect protein expression in cells and tumor tissues. Moreover, the relationship between RIP2-induced autophagy and TMZ resistance was verified in a GBM xenograft model. We determined that RIP2 expression was upregulated in GBM. rRIP2 and RIP2 overexpression induced TMZ resistance in the GBM cell lines. RIP2 overexpressing xenograft tumors have reduced sensitivity to TMZ. In addition, we showed that PD-L1 protein expression was upregulated in GBM tissues with RIP2 overexpression. rRIP2 and RIP2 overexpression induced autophagy in GBM cells through AMPK. Notably, RIP2 upregulated PD-L1 expression through the NF-κB signaling pathway, which induced autophagy and TMZ resistance in GBM cells. Moreover, NF-κB or autophagy inhibition reversed TMZ resistance in RIP2 overexpressing GBM cells in a xenograft model. In conclusion, RIP2 induces TMZ resistance in GBM cells by promoting autophagy through the NF-κB/PD-L1 signaling pathway, indicating that the RIP2/NF-κB/PD-L1 pathway may be therapeutic target for TMZ resistance.

Regulation of Different Types of Cell Death by Noncoding RNAs: Molecular Insights and Therapeutic Implications

Noncoding RNAs (ncRNAs) are crucial regulatory molecules in various biological processes, despite not coding for proteins. ncRNAs are further divided into long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) based on the size of their nucleotides. These ncRNAs play crucial roles in transcriptional, post-transcriptional, and epigenetic regulation. The regulatory roles of noncoding RNAs, including lncRNAs, miRNAs, and circRNAs, are essential in various modalities of cellular death, such as apoptosis, ferroptosis, cuproptosis, pyroptosis, disulfidptosis, and necroptosis. These noncoding RNAs are integral to modulating gene expression and protein functionality during cellular death mechanisms. In apoptosis, lncRNAs, miRNAs, and circRNAs influence the transcription of apoptotic genes. In ferroptosis, these noncoding RNAs target genes and proteins involved in iron homeostasis and oxidative stress responses. For cuproptosis, noncoding RNAs regulate pathways associated with the accumulation of copper ions, leading to cellular death. During pyroptosis, noncoding RNAs modulate inflammatory mediators and caspases, affecting the proinflammatory cell death pathway. In necroptosis, noncoding RNAs oversee the formation and functionality of necrosomes, thereby influencing the balance between cellular survival and death. Disulfidptosis is a unique type of regulated cell death caused by the excessive formation of disulfide bonds within cells, leading to cytoskeletal collapse and oxidative stress, especially under glucose-limited conditions. This investigation highlights the complex mechanisms through which noncoding RNAs coordinate cellular death, emphasizing their therapeutic promise as potential targets, particularly in the domain of cancer treatment.

Inhibition of ATG5-mediated autophagy maintains PMAIP1 stability to promote cell apoptosis and suppress triple-negative breast cancer progression

OBJECTIVE

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer characterized by a high recurrence rate and a lack of effective targeted therapies. The purpose of this study was to investigate the interaction between the pro-apoptotic factor phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1) and autophagy-related protein 5 (ATG5), as well as their regulatory mechanisms in TNBC cell apoptosis and autophagy, to identify potential therapeutic targets for TNBC.

METHODS

TNBC-related datasets were retrieved from The Cancer Genome Atlas and selected by Prediction Analysis of Microarray 50 analysis to assess the expression of PMAIP1 in the samples. Additionally, the expression of PMAIP1 in the TNBC cell lines (MDA-MB-231) was detected using quantitative real-time polymerase chain reaction. In MDA-MB-231 cells, the expression of PMAIP1 and ATG5 was overexpressed or knocked down, and autophagy was inhibited using chloroquine (20 μM). Gene and protein expression levels were evaluated using quantitative real-time polymerase chain reaction and Western blot, respectively. Immunofluorescence was used to observe microtubule-associated protein 1 light chain 3 puncta formation to assess autophagy levels. Furthermore, cell apoptosis, proliferation, migration, and invasion were analyzed using terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, colony formation assay, and Transwell assay.

RESULTS

Compared to the control group, the expression of PMAIP1 was significantly elevated in TNBC tissues and MDA-MB-231 cells. Furthermore, overexpression of PMAIP1 led to a marked increase in apoptosis levels and a remarkable reduction in autophagy levels in MDA-MB-231 cells, while knockdown of PMAIP1 showed the opposite effects. Additionally, knockdown of ATG5 expression or treatment with chloroquine not only resulted in an increase in PMAIP1 expression in a time-dependent manner, but also reduced autophagy levels and enhanced apoptosis levels of cells. Furthermore, simultaneous knockdown of PMAIP1 and ATG5 considerably up-regulated apoptosis levels while down-regulating autophagy levels. Moreover, knockdown of PMAIP1 alone promoted the viability, invasion, and migration abilities of TNBC cells, while dual knockdown reversed these effects.

CONCLUSION

Inhibition of ATG5-mediated autophagy maintains PMAIP1 stability, thereby promoting cell apoptosis and suppressing TNBC progression.

Chloroquine Enhances Chemosensitivity of Breast Cancer via mTOR Inhibition

Background: Chloroquine (CQ) has been extensively validated for its safety as an antimalarial drug. The treatment regimen combining CQ with 5-fluorouracil (5-FU) has demonstrated promising antitumor effects in both in vitro and animal models. However, the clinical application of this combination therapy still faces numerous challenges, primarily due to the unelucidated mechanistic underpinnings. Methods: We validated the synergistic effect of CQ in antitumor therapy using 5-fluorouracil and N-acetylcysteine. Subsequently, we employed lysosomal pH probes and inhibitors (5-BDBD and bafilomycin A1) to verify the mechanism of CQ in synergistic antitumor therapy. Finally, the therapeutic efficacy and underlying mechanisms of CQ were further confirmed through in vivo experiments. Results: Here, we found that CQ can inhibit the ATP-induced activation of mammalian target of rapamycin (mTOR), enhancing the inhibition of 5-FU on the proliferation and survival of tumors. Mechanistically, CQ affects the lysosomal pH value, leading to the inhibition of P2X4 receptor activity. The ATP-P2X4-mTOR axis is consequently disrupted, resulting in the weakened activation of mTOR. Conclusions: Our findings suggest that CQ may inhibit ATP-induced mTOR activation by suppressing P2X4 receptor signaling, thereby altering the apoptosis resistance of tumors. The combination of CQ and 5-FU represents a promising therapeutic strategy, particularly for mTOR-hyperactivated malignancies refractory to conventional chemotherapy. These findings not only advance our understanding of the mechanisms underlying CQ-based combination therapy but also highlight the therapeutic potential of pharmacologically targeting mTOR and its alternative pathways in combination chemotherapy regimens.

Mechanism of ethyl acetate fraction of Amorphophallus konjac against breast cancer based on network pharmacology, molecular docking and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Amorphophallus konjac (Sheliugu), a medicinal and edible herb from East China and regions south of the Yangtze River, exhibits significant antitumor activity. However, its active constituents and mechanisms remain poorly understood.

AIMS OF THE STUDY

This study explores the therapeutic effects of the konjac ethyl acetate fraction (KEAF) in triple-negative breast cancer (TNBC) and elucidates its underlying mechanisms.

MATERIALS AND METHODS

UPLC-MS/MS identified KEAF's chemical components, and network pharmacology determined its key targets in TNBC. Survival curves of essential genes were analyzed using UALCAN, bc-GenExMiner, and Kaplan-Meier plotter databases. Protein expression and prognostic data identified TNBC-linked genes. Molecular docking assessed binding affinities of KEAF's bioactive components with these genes. In vitro experiments validated KEAF's effects on proliferation, migration, cell cycle regulation, and apoptosis.

RESULTS

KEAF contained 15 active compounds and 146 principal targets, with eight key targets identified: TP53, EGFR, AKT1, MYC, STAT3, HIF1A, ESR1, and JUN. GO and KEGG enrichment analyses highlighted the PI3K/Akt signaling pathway as central to KEAF's therapeutic effects. Protein expression and prognostic studies confirmed EGFR and ESR1 as critical in TNBC progression. Molecular docking revealed strong binding of scutellarein and genistein to EGFR and ESR1 (T score >5). In vitro, KEAF inhibited MDA-MB-231 cell proliferation and migration, modulated the cell cycle, and induced apoptosis by downregulating PI3K/Akt signaling.

CONCLUSION

Scutellarein and genistein in KEAF exhibit therapeutic potential against TNBC by targeting EGFR and ESR1 and suppressing the PI3K/Akt signaling pathway.

High antigen-presenting CAF levels correlate with reduced glycosaminoglycan biosynthesis-heparan sulfate/heparin metabolism in immune cells and poor prognosis in esophageal squamous cell carcinoma: Insights from bulk and single-cell transcriptome profiling

In esophageal squamous cell carcinoma (ESCC), the tumor microenvironment (TME) is characterized by a significant accumulation of cancer-associated fibroblasts (CAFs), which play a pivotal role in the host response against tumor cells. While fibroblasts are known to be crucial in the metabolic reprogramming of the TME, the specific metabolic alterations induced by these cells remain largely undefined. Utilizing single-cell RNA sequencing, we have identified a distinct subpopulation of antigen-presenting CAF (apCAF) within ESCC tumors. Our findings reveal that apCAF contribute to adverse patient outcomes by remodeling the tumor metabolic environment. Notably, apCAF modulate the glycosaminoglycan biosynthesis-heparan sulfate/heparin metabolism pathway in T cells, B cells, and macrophages. Disruption of this pathway may facilitate immune evasion by the tumor. These insights underscore the critical role of CAFs in shaping the metabolic landscape of the TME and lay the groundwork for developing therapeutic strategies aimed at enhancing anti-tumor immunity.

Targeting of arachidonic acid-modulated autophagy to enhance the sensitivity of ROS1 + or ALK + non-small cell lung cancer to crizotinib therapy

Background

As an approved targeting drug, crizotinib has been widely used in the treatment of patients with non-small cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK) rearrangements or c-ros oncogene 1 (ROS1) fusions and has demonstrated remarkable therapeutic effects. However, crizotinib-treated patients frequently experience drug resistance, and there are still some underlying mechanisms, which remain unclear. Autophagy, a cellular process that involves the degradation and recycling of cellular components, has been implicated in the development of drug resistance. In this study, we aim to elucidate the mechanisms of crizotinib resistance involving autophagy dysregulation and identify novel therapeutic targets to overcome this resistance.

Methods

We first established a model for crizotinib resistance in HCC78 and H3122 cells. Next, the level of proliferation, apoptosis, autophagy flux, and reactive oxygen species (ROS) of these cells were measured. Subsequently, we analyzed the published single-cell RNA sequencing data from three ALK-rearranged lung cancer organoid samples and performed a metabolomics assay on crizotinib-resistant HCC78 cells. Finally, the therapeutic effects were confirmed in vitro by targeting autophagy flux.

Results

Crizotinib induced cell apoptosis and growth arrest by promoting the accumulation of autophagosomes through the inhibition of autophagy flux in ROS1 + or ALK + NSCLC. In contrast, crizotinib-resistant NSCLC cells showed inactivation of signal transducer and activator of transcription 3 (STAT3) phosphorylation and downregulation of prostaglandin endoperoxide synthase 2 (PTGS2), leading to an increase in the metabolite arachidonic acid (AA). AA further promoted autophagy flux and reduced autophagosome accumulation, driving crizotinib resistance under conditions of drug stress. Moreover, chloroquine (CQ), anti-malaria drug and lysosome inhibitor developed in 1940, could induce cell death in crizotinib-resistant NSCLC by blocking AA-mediated autophagy flux and facilitating autophagosome accumulation, significantly enhancing the treatment efficacy of crizotinib in drug-resistant NSCLC.

Conclusions

We discovered a new mechanism of first generation ALK- and ROS1-TKIs resistance, which points to the role of the metabolite AA in resistance to tyrosine kinase inhibitors. It may potentially provide an alternative strategy to overcoming crizotinib resistance in NSCLC treatment by reversing AA-mediated autophagy.

Hypoxia-Induced VGF Promotes Cell Migration and Invasion in Prostate Cancer via the PI3K/Akt Axis

BACKGROUND

Metastasis is a major cause of prostate cancer (PCa)-related deaths in men. Recent studies have indicated that VGF nerve growth factor inducible (VGF) affects tumor invasion and metastasis. The present study investigated whether VGF is abnormally expressed in PCa and affects PCa progression and investigated the specific regulatory mechanisms by which VGF affects PCa invasion and metastasis.

METHODS

The sh- hypoxia-inducible factor1 alpha (HIF-1α) plasmid was transfected into human cell lines 22Rv1 and C4-2 to create cell lines with stable low expression and overexpression of VGF. Quantitative PCR (qPCR) was performed to detect VGF mRNA. Western blot was performed to detect invasive migration-related proteins. Akt activator SC79 (4 μg/mL) was added. After adding docetaxel (4 nM) to cells transfected with sh-NC and sh-VGF, the capacity of the cells to migrate invasively was assessed using the Transwell and scratch assays. Nude mice were injected with cells stably transfected with sh-NC or sh-VGF and the metastasis of the cancer cells was detected by live imaging and HE staining after the injection of docetaxel (10 mg/kg).

RESULTS

Abnormal levels of VGF in PCa tissue and plasma samples were detected, and VGF knockdown suppressed PCa metastasis. VGF was also shown to affect the invasion and metastasis of PCa cells via PI3K/Akt signaling. VGF knockdown limited PCa metastasis and the inhibitory impact was higher when paired with docetaxel (p < 0.001). After hypoxia induction, both the mRNA and protein levels of VGF and HIF-1α increased, which is associated with a poor prognosis for PCa.

CONCLUSION

By stimulating the PI3K/Akt pathway, VGF encourages the invasive metastasis of PCa. As a result, targeting VGF may be a potential treatment approach for metastatic PCa therapy.

The complex interplay between redox dysregulation and mTOR signaling pathway in cancer: A rationale for cancer treatment

The mechanistic target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that plays a critical role in regulating cellular processes such as growth, proliferation, and metabolism in healthy cells. Dysregulation of mTOR signaling and oxidative stress have been implicated in various diseases including cancer. This review aims to provide an overview of the current understanding of mTOR and its involvement in cell survival and the regulation of cancer cell metabolism as well as its complex interplay with reactive oxygen species (ROS). On the one hand, ROS can inhibit or activate mTOR pathway in cancer cells through various mechanisms. Conversely, mTOR signaling can induce oxidative stress in tumor cells notably due to the inhibition in the expression of antioxidant enzyme genes. Since mTOR is often activated and plays crucial role in cancer cell survival, the use of mTOR inhibitors, which often induce ROS accumulation, could be an interesting approach for cancer treatment. This review will address the advantages, disadvantages, combination strategies, and limitations associated with therapeutic modulation of mTOR signaling pathway in cancer treatment.

Advancements in programmed cell death research in antitumor therapy: a comprehensive overview

Cell death is a normal physiological process within cells that involves multiple pathways, such as normal DNA damage, cell cycle arrest, and programmed cell death (PCD). Cell death has been a hot spot of research in tumor-related fields, especially programmed cell death, which is a key form of cell death and is classified into different types according to the mechanism of occurrence, such as apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and disulfidptosis. Given the important role of PCD in maintaining tissue homeostasis and inhibiting tumorigenesis and development, more and more basic and clinical studies are devoted to revealing its potential application in anti-tumor strategies. The purpose of this review is to systematically review the regulatory mechanisms of PCD and to summarize the latest research progress of anti-tumor treatment strategies based on PCD.

KAT2B inhibits proliferation and invasion via inactivating TGF-β/Smad3 pathway-medicated autophagy and EMT in epithelial ovarian cancer

Lysine acetyltransferase 2B (KAT2B) plays a crucial role in epigenetic regulation and tumor pathogenesis. Our study investigates KAT2B's function in epithelial ovarian cancer (EOC) using in vivo and in vitro methods. Immunohistochemistry showed the KAT2B expression in EOC tissues. RNA sequencing (RNA-seq) further identified altered gene expression profiles following KAT2B silencing in EOC cells. Western blot and qRT-PCR were employed to assess the protein and mRNA expression, respectively. KAT2B downregulated in EOC tissues and correlated with both FIGO stage and grade. KAT2B silencing induced autophagy, enhancing cell proliferation and invasion, while overexpression had opposite effects. In vivo, KAT2B silencing increased tumor volume and weight, mitigated by autophagy inhibitor chloroquine. Bioinformatics and co-immunoprecipitation assays identified a KAT2B-SMAD7 interaction. Mechanistic investigations suggested that KAT2B knockdown enhanced autophagy via activation of the TGF-β/Smad3/7 signaling pathway, thereby driving epithelial-mesenchymal transition (EMT), proliferation, and invasion in EOC. Additionally, our data hint at a potential role for the AKT/mTOR pathway. KAT2B acts as a putative tumor suppressor in EOC, where its reduced expression correlates with advanced disease stages. It is implicated in the regulation of autophagy, proliferation, and invasion via the TGF-β/Smad3/7 pathway, positioning KAT2B as a candidate therapeutic target for EOC interventions.

Targeting STK26 and ATG4B: miR-22-3p as a modulator of autophagy and tumor progression in HCC

Drug-induced protective autophagy significantly affects the efficacy of anticancer therapies. Enhancing tumor cell sensitivity to treatment by inhibiting autophagy is essential for effective cancer therapy. Our study, analyzing data from The Cancer Genome Atlas (TCGA) public database, HCC cell lines, and liver cancer tissue samples, found that miR-22-3p is expressed at low levels in HCC and is significantly associated with clinicopathological features and patient prognosis. Functional assays and xenograft models demonstrated that miR-22-3p suppresses HCC progression. Moreover, Western blot analysis and the LC3B double reporter (mRFP1-EGFP-LC3B) confirmed that miR-22-3p inhibits autophagy in HCC cells. Further investigation identified Sterile 20-like kinase 26 (STK26) and Autophagy Related 4B Cysteine Peptidase (ATG4B) as targets of miR-22-3p. STK26, which is overexpressed in HCC, promotes malignant characteristics such as proliferation, migration, and invasion. Additionally, STK26 facilitates autophagy in HCC by phosphorylating ATG4B at serine 383. miR-22-3p inhibits autophagy by targeting STK26 and ATG4B, thus preventing the phosphorylation of ATG4B at serine 383. Sorafenib treatment increases the levels and phosphorylation of STK26 and ATG4B, inducing protective autophagy. The combination of miR-22-3p with sorafenib demonstrated enhanced antitumor effects both in vitro and in vivo. In conclusion, our findings suggest that miR-22-3p inhibits HCC progression by regulating the expression of STK26 and ATG4B, potentially through autophagy inhibition, thereby increasing sensitivity to sorafenib treatment. This offers a new therapeutic approach for effective HCC.

Application of Gene Editing in Triple-Negative Breast Cancer Research

With the rapid development of gene editing technology, its application in breast cancer has gradually become the focus of research. This article reviews the application of gene editing technology in the treatment of breast cancer, and discusses its challenges and future development directions. The key application areas of gene editing technology in the treatment of breast cancer will be outlined, including the discovery of new therapeutic targets and the development of drugs related to the pathway. Gene editing technology has played an important role in the discovery of new therapeutic targets. Through the use of gene editing technology, breast cancer-related genes are systematically edited to regulate key regulatory factors on related pathways or key tumor suppressor genes such as FOXC1 and BRCA, and the results are analyzed in cell or animal experiments, and the target is obtained from the experimental results, which provides important clues for the development of new drugs. This approach provides an innovative way to find more effective treatment strategies and inhibit tumor growth. In addition, gene editing technology has also promoted the personalization of breast cancer treatment. By analyzing a patient's genomic information, researchers can pinpoint key genetic mutations in a patient's tumor and design personalized treatments. This personalized treatment approach is expected to improve the therapeutic effect and reduce adverse reactions. Finally, the application of gene editing technology also provides support for the development of breast cancer immunotherapy. By editing immune cells to make them more potent against tumors, researchers are trying to develop more effective immunotherapies to bring new treatment options to breast cancer patients.

Interaction Between YTH Domain-Containing Family Protein 2 and SET Domain-Containing Lysine Methyltransferase 7 Suppresses Autophagy in Osteoarthritis Chondrocytes, Exacerbating Cartilage Damage

BACKGROUND AND OBJECTIVE

Osteoarthritis (OA) is characterized by progressive cartilage degeneration mediated by various molecular pathways, including inflammatory and autophagic processes. SET domain-containing lysine methyltransferase 7 (SETD7), a methyltransferase, has been implicated in OA pathology. This study investigates the expression pattern of SETD7 in OA and its role in promoting interleukin-1 beta (IL-1β)-induced chondrocyte injury through modulation of autophagy and inflammation.

METHODS

The expression of SETD7 in cartilage tissues from OA patients and healthy controls was quantified using quantitative reverse transcription PCR and Western blot analysis. Small interfering RNA targeting SETD7 (si-SETD7) was transfected into human articular chondrocytes (HACs) treated with IL-1β to examine its impact on cellular viability, apoptosis, inflammatory responses, and autophagy. Functional assays including Cell Counting Kit-8, flow cytometry, enzyme-linked immunosorbent assay, and commercial kits were employed to assess biochemical changes. Interaction between YTH N6-methyladenosine RNA binding protein 2 (YTHDF2) and SETD7 was explored using RNA immunoprecipitation and co-immunoprecipitation assays.

RESULTS

SETD7 was overexpressed in OA cartilage compared with controls and increased further upon IL-1β treatment. Knockdown of SETD7 in IL-1β-treated HACs improved cellular viability, decreased apoptosis, and reversed the adverse effects on lactate dehydrogenase release and inflammatory markers (tumor necrosis factor-alpha and interleukin-6) while enhancing antioxidant enzymes (catalase, malondialdehyde, and superoxide dismutase). Additionally, autophagy was restored, as evidenced by changes in the levels of autophagy related 5, Beclin1, and sequestosome 1. Interfering with autophagy using chloroquine negated the protective effects of SETD7 knockdown. Furthermore, YTHDF2 was found to stabilize SETD7 mRNA, influencing its expression and enhancing IL-1β-induced chondrocyte injury.

CONCLUSION

SETD7 plays a critical role in the pathogenesis of OA by modulating chondrocyte survival, apoptosis, inflammation, and autophagy. The interaction between YTHDF2 and SETD7 exacerbates chondrocyte injury under inflammatory conditions, highlighting potential therapeutic targets for OA treatment. The YTHDF2/SETD7 axis offers a novel insight into the molecular mechanisms governing cartilage degeneration in OA.

Protein arginine methyltransferase 5 confers the resistance of triple-negative breast cancer to nanoparticle albumin-bound paclitaxel by enhancing autophagy through the dimethylation of ULK1

Chemotherapy remains the major strategy for treating triple-negative breast cancer (TNBC); however, frequently acquired chemoresistance greatly limits the treatment outcomes. Protein arginine methyltransferase 5 (PRMT5), which modulates arginine methylation, is important in chemoresistance acquisition across various cancers. The function of PRMT5 in the development of chemoresistance in TNBC is still not well understood. This work focused on defining PRMT5's function in contributing to the chemoresistance in TNBC and demonstrating the possible mechanisms involved. Two TNBC cell lines resistant to nanoparticle albumin-bound paclitaxel (Nab-PTX), designated MDA-MB-231/R and MDA-MB-468/R, were developed. The expression of PRMT5 was markedly elevated in the cytoplasm of Nab-PTX-resistant cells accompanied with enhanced autophagy. The depletion of PRMT5 rendered these cells sensitive to Nab-PTX-evoked cytotoxicity. The autophagic flux was upregulated in Nab-PTX-resistant cells, which was markedly repressed by PRMT5 depletion. The dimethylation of ULK1 was markedly elevated in Nab-PTX-resistant cells, which was decreased by silencing PRMT5. Re-expression of PRMT5 in PRMT5-depleted cells restored the dimethylation and activation of ULK1 as well as the autophagic flux, while the catalytically-dead PRMT5 (R368A) mutant showed no significant effects. The depletion of PRMT5 rendered the subcutaneous tumors formed by Nab-PTX-resistant TNBC cells sensitive to Nab-PTX. The findings of this work illustrate that PRMT5 confers chemoresistance of TNBC by enhancing autophagy through dimethylation and the activation of ULK1, revealing a novel mechanism for understanding the acquisition of chemoresistance in TNBC. Targeting PRMT5 could be a viable approach for overcoming chemoresistance in the treatment of TNBC.

Anticancer role of flubendazole: Effects and molecular mechanisms (Review)

Flubendazole, an anthelmintic agent with a well-established safety profile, has emerged as a promising anticancer drug that has demonstrated efficacy against a spectrum of cancer types over the past decade. Its anticancer properties encompass a multifaceted mechanism of action, including the inhibition of cancer cell proliferation, disruption of microtubule dynamics, regulation of cell cycle, autophagy, apoptosis, suppression of cancer stem cell characteristics, promotion of ferroptosis and inhibition of angiogenesis. The present review aimed to provide a comprehensive overview of the molecular underpinnings of the anticancer activity of flubendazole, highlighting key molecules and regulatory pathways. Given the breadth of the potential of flubendazole, further research is imperative to identify additional cancer types sensitive to flubendazole, refine experimental methodologies for enhancing its reliability, uncover synergistic drug combinations, improve its bioavailability and explore innovative administration methods. The present review provided a foundation for future studies on the role of flubendazole in oncology and described its molecular mechanisms of action.

Mycoplasma bovis activates apoptotic caspases to suppress xenophagy for its intracellular survival

Mammalian caspases are categorized into apoptotic and inflammatory types. Apoptotic caspases mediate apoptosis activation, while inflammatory caspases participate in inflammasome activation. Previous studies have shown that apoptotic caspases regulate autophagy in both cancer and pharmacological treatment models. However, the relationship between apoptotic caspases and xenophagy during pathogen infection remains elusive. In the current study, we used Mycoplasma bovis (M. bovis) as a model pathogen investigating the relationship between apoptotic caspases and xenophagy during infection. We found that M. bovis activated apoptotic caspases by triggering mitochondrial damage in macrophages, and the intracellular survival of M. bovis was enhanced by the activation of apoptotic caspases and restricted by the inhibition of apoptotic caspases. Moreover, confocal microscopy and Western blot analysis revealed that the activation of apoptotic caspases impedes host xenophagy by cleaving autophagy-related protein Beclin 1. Our findings indicate that M. bovis utilizes host apoptotic caspases to suppress xenophagy, thereby enhancing its intracellular survival. This research contributes to understanding the interplay between apoptotic caspases and xenophagy during pathogen infection, offering novel insights into the intracellular survival mechanisms of mycoplasma in macrophages.

Triggering Pyroptosis by Doxorubicin-Loaded Multifunctional Nanoparticles in Combination with Decitabine for Breast Cancer Chemoimmunotherapy

Pyroptosis, a form of programmed cell death, holds great promise for breast cancer treatment. However, the downregulation of gasdermin E (GSDME) limits the effectiveness of pyroptosis. To address this challenge, we developed a folic acid-modified and glutathione/reactive oxygen species dual-responsive nanocarrier (FPSD NPs) for the targeted delivery of doxorubicin (DOX). Through the combination with DNA methyltransferase inhibitor decitabine (DAC), the GSDME protein expression was significantly increased in 4T1 cells, resulting in cell swelling and ballooning, which are characteristic features of pyroptosis. In vivo experiments further demonstrated the antitumor efficacy of DAC + DOX@FPSD NPs, and the 4T1-bearing mice treated with DAC + DOX@FPSD NPs exhibited reduced tumor volumes, minimized tumor weights, decreased Ki67-positive cells, increased TUNEL apoptosis ratios, and pronounced lesions in H&E staining. Furthermore, DAC + DOX@FPSD NP treatment could promote pyroptosis-associated antitumor immunity, as evidenced by the increased presence of CD3+, CD4+, and CD8+ T cells, heightened secretion of tumor necrosis factor-α and interferon-γ, elevated high-mobility group box-1 levels, and enhanced calreticulin exposure. The FPSD nanocarrier developed in this study had favorable stability, active targeting ability, biocompatibility, and controlled release properties, and the DAC + DOX@FPSD NPs represented an approach to antitumor therapy by inducing pyroptosis, which offers a promising avenue for breast cancer treatment.

Targeting oncogenic MAGEA6 sensitizes triple negative breast cancer to doxorubicin through its autophagy and ferroptosis by stabling AMPKα1

Melanoma-associated antigen A6 (MAGEA6) is well known to have oncogenic activity, but the underlying mechanisms by which it regulates tumor progression and chemo-resistance, especially in triple-negative breast cancer (TNBC), have been unknown. In the study, the differential expression genes (DEGs) in TNBC tumor tissues and TNBC-resistant tumor tissues were analyzed based on TCGA and GEO datasets. MAGEA6, as the most significantly expressed gene, was analyzed by RT-qPCR, western blotting and immunohistochemistry assay in TNBC cell lines and tumor tissues. The potential mechanisms that influence chemo-resistance were also evaluated. Results displayed that MAGEA6 was highly expressed in TNBC and involved in drug resistance. MAGEA6 silencing enhanced the chemo-sensitivity of TNBC to doxorubicin (DOX) in vitro and in vivo, as determined by decreasing IC50 value, proliferation and invasion capacity, and triggering apoptosis. Mechanistically, it was shown that MAGEA6 depletion sensitized TNBC to DOX via regulating autophagy. Ubiquitination assay displayed that knockdown of MAGEA6 decreased the AMPKα1 ubiquitination, thereby elevating the levels of AMPKα1 and p-AMPKα in TNBC cells. Importantly, AMPK inhibitor (Compound C) can reduce the LC3II/I level induced by sh-MAGEA6, indicating that sh-MAGEA6 activated AMPK signaling through suppressing AMPKα1 ubiquitination and then facilitated autophagy in TNBC. Furthermore, we also observed that AMPK is required for SLC7A11 to regulate ferroptosis, and supported the crux roles of MAGEA6/AMPK/SLC7A11-mediated ferroptosis on modulating DOX sensitivity in TNBC cells. These findings indicated that targeting MAGEA6 can enhance the chemo-sensitivity in TNBC via activation of autophagy and ferroptosis; its mechanism involves AMPKα1-dependent autophagy and AMPKα1/SLC7A11-induced ferroptosis.

Recent advancement in developing small molecular inhibitors targeting key kinase pathways against triple-negative breast cancer

Triple-negative breast cancer (TNBC) stands out as the most formidable variant of breast cancer, predominantly affecting younger women and characterized by a bleak outlook and a high likelihood of spreading. The absence of safe and effective targeted treatments leaves standard cytotoxic chemotherapy as the primary option. The role of protein kinases, frequently altered in many cancers, is significant in the advancement and drug resistance of TNBC, making them a logical target for creating new, potent therapies against TNBC. Recently, an array of promising small molecules aimed at various kinases have been developed specifically for TNBC, with combination studies showing a synergistic improvement in combatting this condition. This review underscores the effectiveness of small molecule kinase inhibitors in battling the most lethal form of breast cancer and sheds light on prospective pathways for crafting novel treatments.

Formononetin triggers ferroptosis in triple-negative breast cancer cells by regulating the mTORC1/SREBP1/SCD1 pathway

Introduction

Triple-negative breast cancer (TNBC) is the most malignant type of breast cancer, and its prognosis is still the worst. It is necessary to constantly explore the pathogenesis and effective therapeutic targets of TNBC. Formononetin is an active ingredient with anti-tumor effects that we screened earlier. The main purpose of this study is to elucidate mechanism of the inhibitory effect of Formononetin on TNBC.

Methods

We conducted experiments through both in vivo and in vitro methodologies. The in vivo experiments utilized a nude mice xenotransplantation model, while the in vitro investigations employed two breast cancer cell lines, MDA-MB-231 and MDA-MB-468. Concurrently, ferroptosis associated proteins, lipid peroxide levels, and proteins related to the rapamycin complex 1 were analyzed in both experimental settings.

Results

In our study, Formononetin exhibits significant inhibitory effects on the proliferation of triple TNBC, both in vivo and in vitro. Moreover, it elicits an increase in lipid peroxide levels, downregulates the expression of ferroptosis-associated proteins GPX4 and xCT, and induces ferroptosis in breast cancer cells. Concurrently, Formononetin impedes the formation of the mammalian target of rapamycin complex 1 (mTORC1) and suppresses the expression of downstream Sterol regulatory element-binding protein 1(SREBP1). The utilization of breast cancer cells with SREBP1 overexpression or knockout demonstrates that Formononetin induces ferroptosis by modulating the mTORC1-SREBP1 signaling axis.

Discussion

In conclusion, this study provides evidence that Formononetin exerts an anti-proliferative effect on triple-negative breast cancer by inducing ferroptosis. Moreover, the mTORC1-SREBP1 signal axis is identified as the primary mechanism through which formononetin exerts its therapeutic effects. These findings suggest that formononetin holds promise as a potential targeted drug for clinical treatment of TNBC.

A naturally occurring 22-amino acid fragment of human hemoglobin A inhibits autophagy and HIV-1

Autophagy is an evolutionarily ancient catabolic pathway and has recently emerged as an integral part of the innate immune system. While the core machinery of autophagy is well defined, the physiological regulation of autophagy is less understood. Here, we identify a C-terminal fragment of human hemoglobin A (HBA1, amino acids 111-132) in human bone marrow as a fast-acting non-inflammatory inhibitor of autophagy initiation. It is proteolytically released from full-length HBA1 by cathepsin E, trypsin or pepsin. Biochemical characterization revealed that HBA1(111-132) has an in vitro stability of 52 min in human plasma and adopts a flexible monomeric conformation in solution. Structure-activity relationship studies revealed that the C-terminal 13 amino acids of HBA1(120-132) are sufficient to inhibit autophagy, two charged amino acids (D127, K128) mediate solubility, and two serines (S125, S132) are required for function. Successful viruses like human immunodeficiency virus 1 (HIV-1) evolved strategies to subvert autophagy for virion production. Our results show that HBA1(120-132) reduced virus yields of lab-adapted and primary HIV-1. Summarizing, our data identifies naturally occurring HBA1(111-132) as a physiological, non-inflammatory antagonist of autophagy. Optimized derivatives of HBA1(111-132) may offer perspectives to restrict autophagy-dependent viruses.

Enhancing antitumor efficacy of CLDN18.2-directed antibody-drug conjugates through autophagy inhibition in gastric cancer

Claudin18.2 (CLDN18.2) is overexpressed in cancers of the digestive system, rendering it an ideal drug target for antibody-drug conjugates (ADCs). Despite many CLDN18.2-directed ADCs undergoing clinical trials, the inconclusive underlying mechanisms pose a hurdle to extending the utility of these agents. In our study, αCLDN18.2-MMAE, an ADC composed of an anti-CLDN18.2 monoclonal antibody and the tubulin inhibitor MMAE, induced a dose-dependent apoptosis via the cleavage of caspase-9/PARP proteins in CLDN18.2-positive gastric cancer cells. It was worth noting that autophagy was remarkably activated during the αCLDN18.2-MMAE treatment, which was characterized by the accumulation of autophagosomes, the conversion of autophagy marker LC3 from its form I to II, and the complete autophagic flux. Inhibiting autophagy by autophagy inhibitor LY294002 remarkably enhanced αCLDN18.2-MMAE-induced cytotoxicity and caspase-mediated apoptosis, indicating the cytoprotective role of autophagy in CLDN18.2-directed ADC-treated gastric cancer cells. Combination with an autophagy inhibitor significantly potentiated the in vivo antitumoral efficacy of αCLDN18.2-MMAE. Besides, the Akt/mTOR pathway inactivation was demonstrated to be implicated in the autophagy initiation in αCLDN18.2-MMAE-treated gastric cancer cells. In conclusion, our study highlighted a groundbreaking investigation into the mechanism of the CLDN18.2-directed ADC, focusing on the crucial role of autophagy, providing a novel insight to treat gastric cancer by the combination of CLDN18.2-directed ADC and autophagy inhibitor.

Non-viral vectors combined delivery of siRNA and anti-cancer drugs to reverse tumor multidrug resistance

Multidrug resistance (MDR) of tumors is one of the main reasons for the failure of chemotherapy. Multidrug resistance refers to the cross-resistance of tumor cells to multiple antitumor drugs with different structures and mechanisms of action. Current strategies to reverse multidrug resistance in tumors include MDR inhibitors and RNAi technology. siRNA is a small molecule RNA that is widely used in RNAi technology and has the characteristics of being prepared in large quantities and chemically modified. However, siRNA is susceptible to degradation in vivo. The effect of siRNA therapy alone is not ideal, so siRNA and anticancer drugs are administered in combination to reverse the MDR of tumors. Non-viral vectors are now commonly used to deliver siRNA and anticancer drugs to tumor sites. This article will review the progress of siRNA and chemotherapeutic drug delivery systems and their mechanisms for reversing multidrug resistance.

Cell death pathways: molecular mechanisms and therapeutic targets for cancer

Cell death regulation is essential for tissue homeostasis and its dysregulation often underlies cancer development. Understanding the different pathways of cell death can provide novel therapeutic strategies for battling cancer. This review explores several key cell death mechanisms of apoptosis, necroptosis, autophagic cell death, ferroptosis, and pyroptosis. The research gap addressed involves a thorough analysis of how these cell death pathways can be precisely targeted for cancer therapy, considering tumor heterogeneity and adaptation. It delves into genetic and epigenetic factors and signaling cascades like the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathways, which are critical for the regulation of cell death. Additionally, the interaction of the microenvironment with tumor cells, and particularly the influence of hypoxia, nutrient deprivation, and immune cellular interactions, are explored. Emphasizing therapeutic strategies, this review highlights emerging modulators and inducers such as B cell lymphoma 2 (BCL2) homology domain 3 (BH3) mimetics, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), chloroquine, and innovative approaches to induce ferroptosis and pyroptosis. This review provides insights into cancer therapy's future direction, focusing on multifaceted approaches to influence cell death pathways and circumvent drug resistance. This examination of evolving strategies underlines the considerable clinical potential and the continuous necessity for in-depth exploration within this scientific domain.

O-Sialoglycoprotein Endopeptidase Deficiency Impairs Proteostasis and Induces Autophagy in Human Embryonic Stem Cells

The OSGEP gene encodes O-sialoglycoprotein endopeptidase, a catalytic unit of the highly conserved KEOPS complex (Kinase, Endopeptidase, and Other Proteins of small Size) that regulates the second biosynthetic step in the formation of N-6-threonylcarbamoyladenosine (t6A). Mutations in KEOPS cause Galloway-Mowat syndrome (GAMOS), whose cellular function in mammals and underlying molecular mechanisms are not well understood. In this study, we utilized lentivirus-mediated OSGEP knockdown to generate OSGEP-deficient human embryonic stem cells (hESCs). OSGEP-knockdown hESCs exhibited reduced stemness factor expression and G2/M phase arrest, indicating a potential role of OSGEP in the regulation of hESC fate. Additionally, OSGEP silencing led to enhanced protein synthesis and increased aggregation of proteins, which further induced inappropriate autophagy, as evidenced by the altered expression of P62 and the conversion of LC3-I to LC3-II. The above findings shed light on the potential involvement of OSGEP in regulating pluripotency and differentiation in hESCs while simultaneously highlighting its crucial role in maintaining proteostasis and autophagy, which may have implications for human disease.

Pharmacology Progresses and Applications of Chloroquine in Cancer Therapy

Chloroquine is a common antimalarial drug and is listed in the World Health Organization Standard List of Essential Medicines because of its safety, low cost and ease of use. Besides its antimalarial property, chloroquine also was used in anti-inflammatory and antivirus, especially in antitumor therapy. A mount of data showed that chloroquine mainly relied on autophagy inhibition to exert its antitumor effects. However, recently, more and more researches have revealed that chloroquine acts through other mechanisms that are autophagy-independent. Nevertheless, the current reviews lacked a comprehensive summary of the antitumor mechanism and combined pharmacotherapy of chloroquine. So here we focused on the antitumor properties of chloroquine, summarized the pharmacological mechanisms of antitumor progression of chloroquine dependent or independent of autophagy inhibition. Moreover, we also discussed the side effects and possible application developments of chloroquine. This review provided a more systematic and cutting-edge knowledge involved in the anti-tumor mechanisms and combined pharmacotherapy of chloroquine in hope of carrying out more in-depth exploration of chloroquine and obtaining more clinical applications.

Challenges of Regulated Cell Death: Implications for Therapy Resistance in Cancer

Regulated cell death, a regulatory form of cell demise, has been extensively studied in multicellular organisms. It plays a pivotal role in maintaining organismal homeostasis under normal and pathological conditions. Although alterations in various regulated cell death modes are hallmark features of tumorigenesis, they can have divergent effects on cancer cells. Consequently, there is a growing interest in targeting these mechanisms using small-molecule compounds for therapeutic purposes, with substantial progress observed across various human cancers. This review focuses on summarizing key signaling pathways associated with apoptotic and autophagy-dependent cell death. Additionally, it explores crucial pathways related to other regulated cell death modes in the context of cancer. The discussion delves into the current understanding of these processes and their implications in cancer treatment, aiming to illuminate novel strategies to combat therapy resistance and enhance overall cancer therapy.

Nicotinamide Supplementation Mitigates Oxidative Injury of Bovine Intestinal Epithelial Cells through Autophagy Modulation

The small intestine is important to the digestion and absorption of rumen undegradable nutrients, as well as the barrier functionality and immunological responses in ruminants. Oxidative stress induces a spectrum of pathophysiological symptoms and nutritional deficits, causing various gastrointestinal ailments. Previous studies have shown that nicotinamide (NAM) has antioxidant properties, but the potential mechanism has not been elucidated. The aim of this study was to explore the effects of NAM on hydrogen peroxide (H2O2)-induced oxidative injury in bovine intestinal epithelial cells (BIECs) and its potential mechanism. The results showed that NAM increased the cell viability and total antioxidant capacity (T-AOC) and decreased the release of lactate dehydrogenase (LDH) in BIECs challenged by H2O2. The NAM exhibited increased expression of catalase, superoxide dismutase 2, and tight junction proteins. The expression of autophagy-related proteins was increased in BIECs challenged by H2O2, and NAM significantly decreased the expression of autophagy-related proteins. When an autophagy-specific inhibitor was used, the oxidative injury in BIECs was not alleviated by NAM, and the T-AOC and the release of LDH were not affected. Collectively, these results indicated that NAM could alleviate oxidative injury in BIECs by enhancing antioxidant capacity and increasing the expression of tight junction proteins, and autophagy played a crucial role in the alleviation.

Desloratadine alleviates ALS-like pathology in hSOD1G93A mice via targeting 5HTR2A on activated spinal astrocytes

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with progressive loss of motor neurons in the spinal cord, cerebral cortex and brain stem. ALS is characterized by gradual muscle atrophy and dyskinesia. The limited knowledge on the pathology of ALS has impeded the development of therapeutics for the disease. Previous studies have shown that autophagy and astrocyte-mediated neuroinflammation are involved in the pathogenesis of ALS, while 5HTR2A participates in the early stage of astrocyte activation, and 5HTR2A antagonism may suppress astrocyte activation. In this study, we evaluated the therapeutic effects of desloratadine (DLT), a selective 5HTR2A antagonist, in human SOD1G93A (hSOD1G93A) ALS model mice, and elucidated the underlying mechanisms. HSOD1G93A mice were administered DLT (20 mg·kg-1·d-1, i.g.) from the age of 8 weeks for 10 weeks or until death. ALS onset time and lifespan were determined using rotarod and righting reflex tests, respectively. We found that astrocyte activation accompanying with serotonin receptor 2 A (5HTR2A) upregulation in the spinal cord was tightly associated with ALS-like pathology, which was effectively attenuated by DLT administration. We showed that DLT administration significantly delayed ALS symptom onset time, prolonged lifespan and ameliorated movement disorders, gastrocnemius injury and spinal motor neuronal loss in hSOD1G93A mice. Spinal cord-specific knockdown of 5HTR2A by intrathecal injection of adeno-associated virus9 (AAV9)-si-5Htr2a also ameliorated ALS pathology in hSOD1G93A mice, and occluded the therapeutic effects of DLT administration. Furthermore, we demonstrated that DLT administration promoted autophagy to reduce mutant hSOD1 levels through 5HTR2A/cAMP/AMPK pathway, suppressed oxidative stress through 5HTR2A/cAMP/AMPK/Nrf2-HO-1/NQO-1 pathway, and inhibited astrocyte neuroinflammation through 5HTR2A/cAMP/AMPK/NF-κB/NLRP3 pathway in the spinal cord of hSOD1G93A mice. In summary, 5HTR2A antagonism shows promise as a therapeutic strategy for ALS, highlighting the potential of DLT in the treatment of the disease. DLT as a 5HTR2A antagonist effectively promoted autophagy to reduce mutant hSOD1 level through 5HTR2A/cAMP/AMPK pathway, suppressed oxidative stress through 5HTR2A/cAMP/AMPK/Nrf2-HO-1/NQO-1 pathway, and inhibited astrocytic neuroinflammation through 5HTR2A/cAMP/AMPK/NF-κB/NLRP3 pathway in the spinal cord of hSOD1G93A mice.

GL-V9 inhibits the activation of AR-AKT-HK2 signaling networks and induces prostate cancer cell apoptosis through mitochondria-mediated mechanism

Prostate cancer (PCa) is a serious health concern for men due to its high incidence and mortality rate. The first therapy typically adopted is androgen deprivation therapy (ADT). However, patient response to ADT varies, and 20-30% of PCa cases develop into castration-resistant prostate cancer (CRPC). This article investigates the anti-PCa effect of a drug candidate named GL-V9 and highlights the significant mechanism involving the AKT-hexokinase II (HKII) pathway. In both androgen receptor (AR)-expressing 22RV1 cells and AR-negative PC3 cells, GL-V9 suppressed phosphorylated AKT and mitochondrial location of HKII. This led to glycolytic inhibition and mitochondrial pathway-mediated apoptosis. Additionally, GL-V9 inhibited AR activity in 22RV1 cells and disrupted the feedback activation of AKT signaling in condition of AR inhibition. This disruption greatly increased the anti-PCa efficacy of the AR antagonist bicalutamide. In conclusion, we present a novel anti-PCa candidate and combination drug strategies to combat CRPC by intervening in the AR-AKT-HKII signaling network.

TRF2 as novel marker of tumor response to taxane-based therapy: from mechanistic insight to clinical implication

BACKGROUND

Breast Cancer (BC) can be classified, due to its heterogeneity, into multiple subtypes that differ for prognosis and clinical management. Notably, triple negative breast cancer (TNBC) - the most aggressive BC form - is refractory to endocrine and most of the target therapies. In this view, taxane-based therapy still represents the elective strategy for the treatment of this tumor. However, due variability in patients' response, management of TNBC still represents an unmet medical need. Telomeric Binding Factor 2 (TRF2), a key regulator of telomere integrity that is over-expressed in several tumors, including TNBC, has been recently found to plays a role in regulating autophagy, a degradative process that is involved in drug detoxification. Based on these considerations, we pointed, here, at investigating if TRF2, regulating autophagy, can affect tumor sensitivity to therapy.

METHODS

Human TNBC cell lines, over-expressing or not TRF2, were subjected to treatment with different taxanes and drug efficacy was tested in terms of autophagic response and cell proliferation. Autophagy was evaluated first biochemically, by measuring the levels of LC3, and then by immunofluorescence analysis of LC3-puncta positive cells. Concerning the proliferation, cells were subjected to colony formation assays associated with western blot and FACS analyses. The obtained results were then confirmed also in mouse models. Finally, the clinical relevance of our findings was established by retrospective analysis on a cohort of TNBC patients subjected to taxane-based neoadjuvant chemotherapy.

RESULTS

This study demonstrated that TRF2, inhibiting autophagy, is able to increase the sensitivity of TNBC cells to taxanes. The data, first obtained in in vitro models, were then recapitulated in preclinical mouse models and in a cohort of TNBC patients, definitively demonstrating that TRF2 over-expression enhances the efficacy of taxane-based neoadjuvant therapy in reducing tumor growth and its recurrence upon surgical intervention.

CONCLUSIONS

Based on our finding it is possible to conclude that TRF2, already known for its role in promoting tumor formation and progression, might represents an Achilles' heel for cancer. In this view, TRF2 might be exploited as a putative biomarker to predict the response of TNBC patients to taxane-based neoadjuvant chemotherapy.

Lysosome-related biomarkers in preeclampsia and cancers: Machine learning and bioinformatics analysis

BACKGROUND

Lysosomes serve as regulatory hubs, and play a pivotal role in human diseases. However, the precise functions and mechanisms of action of lysosome-related genes remain unclear in preeclampsia and cancers. This study aimed to identify lysosome-related biomarkers in preeclampsia, and further explore the biomarkers shared between preeclampsia and cancers.

MATERIALS AND METHODS

We obtained GSE60438 and GSE75010 datasets from the Gene Expression Omnibus database, pre-procesed them and merged them into a training cohort. The limma package in R was used to identify the differentially expressed mRNAs between the preeclampsia and normal control groups. Differentially expressed lysosome-related genes were identified by intersecting the differentially expressed mRNAs and lysosome-related genes obtained from Gene Ontology and GSEA databases. Gene Ontology annotations and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were performed using the DAVID database. The CIBERSORT method was used to analyze immune cell infiltration. Weighted gene co-expression analyses and three machine learning algorithm were used to identify lysosome-related diagnostic biomarkers. Lysosome-related diagnostic biomarkers were further validated in the testing cohort GSE25906. Nomogram diagnostic models for preeclampsia were constructed. In addition, pan-cancer analysis of lysosome-related diagnostic biomarkers were identified by was performed using the TIMER, Sangebox and TISIDB databases. Finally, the Drug-Gene Interaction, TheMarker and DSigDB Databases were used for drug-gene interactions analysis.

RESULTS

A total of 11 differentially expressed lysosome-related genes were identified between the preeclampsia and control groups. Three molecular clusters connected to lysosome were identified, and enrichment analysis demonstrated their strong relevance to the development and progression of preeclampsia. Immune infiltration analysis revealed significant immunity heterogeneity among different clusters. GBA, OCRL, TLR7 and HEXB were identified as lysosome-related diagnostic biomarkers with high AUC values, and validated in the testing cohort GSE25906. Nomogram, calibration curve, and decision curve analysis confirmed the accuracy of predicting the occurrence of preeclampsia based on OCRL and HEXB. Pan-cancer analysis showed that GBA, OCRL, TLR7 and HEXB were associated with the prognosis of patients with various tumors and tumor immune cell infiltration. Twelve drugs were identified as potential drugs for the treatment of preeclampsia and cancers.

CONCLUSION

This study identified GBA, OCRL, TLR7 and HEXB as potential lysosome-related diagnostic biomarkers shared between preeclampsia and cancers.

Thrombospondin-1-mediated crosstalk between autophagy and oxidative stress orchestrates repair of blast lung injury

Coal mining carries inherent risks of catastrophic gas explosions capable of inflicting severe lung injury. Using complementary in vivo and in vitro models, we explored mechanisms underlying alveolar epithelial damage and repair following a gas explosion in this study. In a rat model, the gas explosion was demonstrated to trigger inflammation and injury within the alveolar epithelium. The following scRNA-sequencing revealed that alveolar epithelial cells exhibited the most profound transcriptomic changes after gas explosion compared to other pulmonary cell types. In the L2 alveolar epithelial cells, the blast was found to cause autophagic flux by inducing autophagosome formation, LC3 lipidation, and p62 degradation. Transcriptomic profiling of the L2 cells identified PI3K-Akt and p53 pathways as critical modulators governing autophagic and oxidative stress responses to blast damage. Notably, Thrombospondin-1 (Thbs1) was determined for the first time as a pivotal node interconnecting these two pathways. The findings of this study illuminate intricate mechanisms of alveolar epithelial injury and recovery after blast trauma, highlighting autophagic and oxidative stress responses mediated by Thbs1-associated PI3K-Akt and p53 pathways as high-value therapeutic targets, and strategic modulation of these pathways in future studies may mitigate lung damage by reducing oxidative stress while engaging endogenous tissue repair processes like autophagy.

Chloroquine and Chemotherapeutic Compounds in Experimental Cancer Treatment

Chloroquine (CQ) and its derivate hydroxychloroquine (HCQ), the compounds with recognized ability to suppress autophagy, have been tested in experimental works and in clinical trials as adjuvant therapy for the treatment of tumors of different origin to increase the efficacy of cytotoxic agents. Such a strategy can be effective in overcoming the resistance of cancer cells to standard chemotherapy or anti-angiogenic therapy. This review presents the results of the combined application of CQ/HCQ with conventional chemotherapy drugs (doxorubicin, paclitaxel, platinum-based compounds, gemcitabine, tyrosine kinases and PI3K/Akt/mTOR inhibitors, and other agents) for the treatment of different malignancies obtained in experiments on cultured cancer cells, animal xenografts models, and in a few clinical trials. The effects of such an approach on the viability of cancer cells or tumor growth, as well as autophagy-dependent and -independent molecular mechanisms underlying cellular responses of cancer cells to CQ/HCQ, are summarized. Although the majority of experimental in vitro and in vivo studies have shown that CQ/HCQ can effectively sensitize cancer cells to cytotoxic agents and increase the potential of chemotherapy, the results of clinical trials are often inconsistent. Nevertheless, the pharmacological suppression of autophagy remains a promising tool for increasing the efficacy of standard chemotherapy, and the development of more specific inhibitors is required.

Targeting autophagy for breast cancer prevention and therapy: From classical methods to phytochemical agents

Breast cancer is a heterogeneous illness comprising diverse biological subtypes, each of which differs in incidence, response to therapies, and prognosis. Despite the presence of novel medications that effectively target vital cellular signaling pathways and their application in clinical practice, breast cancer can still develop resistance to therapies by various mechanisms. Autophagy is a conserved catabolic cellular process that maintains intracellular metabolic homeostasis by removing dysfunctional or unnecessary cellular materials to recycle cytosolic components. This process serves as an adaptive survival response to diverse stress stimuli, thereby contributing to tumor initiation, progression, and drug resistance, leading to restriction of the effectiveness of chemotherapeutic treatments. Regarding this potential role of autophagy, molecular regulation and signal transduction of this process represent an attractive approach to combat cancer development and drug resistance. Among various therapeutic agents, bioactive plant-derived compounds have received significant interest as promising anticancer drugs. A plethora of evidence has shown that phytochemicals with the capacity to modulate autophagy may have the potential to be used as inhibitors of breast cancer growth. In this review, we describe recent findings on autophagy targeting along with conventional methods for breast cancer therapy. Subsequently, we introduce phytochemical compounds with the capacity to modulate autophagy for breast cancer treatment.

Astragaloside IV enhances the sensitivity of breast cancer stem cells to paclitaxel by inhibiting stemness

Background

Chemotherapy is one of the common treatments for breast cancer. The induction of cancer stem cells (CSCs) is an important reason for chemotherapy failure and breast cancer recurrence. Astragaloside IV (ASIV) is one of the effective components of the traditional Chinese medicine (TCM) Astragalus membranaceus, which can improve the sensitivity of various tumors to chemotherapy drugs. Here, we explored the sensitization effect of ASIV to chemotherapy drug paclitaxel (PTX) in breast cancer from the perspective of CSCs.

Methods

The study included both in vitro and in vivo experiments. CSCs from the breast cancer cell line MCF7 with stem cell characteristics were successfully induced in vitro. Cell viability and proliferation were detected using the Cell Counting Kit-8 (CCK-8) and colony formation assays, and flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) methods were performed to detect cell apoptosis. Stemness-related protein expression was determined by western blotting (WB) and immunohistochemistry (IHC). Body weight, histopathology, and visceral organ damage of mice were used to monitor drug toxicity.

Results

The expression of stemness markers including Sox2, Nanog, and ALDHA1 was stronger in MCF7-CSCs than in MCF7. PTX treatment inhibited the proliferation of tumor cells by promoting cell apoptosis, whereas the stemness of breast cancer stem cells (BCSCs) resisted the effects of PTX. ASIV decreased the stemness of BCSCs, increased the sensitivity of BCSCs to PTX, and synergistically promoted PTX-induced apoptosis of breast cancer cells. Our results showed that the total cell apoptosis rate increased by about 25% after adding ASIV compared with BCSCs treated with PTX alone. The in vivo experiments demonstrated that ASIV enhanced the ability of PTX to inhibit the growth of breast cancer. WB and IHC showed that ASIV reduced the stemness of CSCs.

Conclusions

In this study, the resistance of breast cancer to PTX was attributed to the existence of CSCs; ASIV weakened the resistance of MCF7-CSCs to PTX by significantly attenuating the hallmarks of breast cancer stemness and improved the efficacy of PTX.

Breast Cancer Chemoresistance: Insights into the Regulatory Role of lncRNA

Long noncoding RNAs (lncRNAs) are a subclass of noncoding RNAs composed of more than 200 nucleotides without the ability to encode functional proteins. Given their involvement in critical cellular processes such as gene expression regulation, transcription, and translation, lncRNAs play a significant role in organism homeostasis. Breast cancer (BC) is the second most common cancer worldwide and evidence has shown a relationship between aberrant lncRNA expression and BC development. One of the main obstacles in BC control is multidrug chemoresistance, which is associated with the deregulation of multiple mechanisms such as efflux transporter activity, mitochondrial metabolism reprogramming, and epigenetic regulation as well as apoptosis and autophagy. Studies have shown the involvement of a large number of lncRNAs in the regulation of such pathways. However, the underlying mechanism is not clearly elucidated. In this review, we present the principal mechanisms associated with BC chemoresistance that can be directly or indirectly regulated by lncRNA, highlighting the importance of lncRNA in controlling BC chemoresistance. Understanding these mechanisms in deep detail may interest the clinical outcome of BC patients and could be used as therapeutic targets to overcome BC therapy resistance.

Biology of childhood hepatoblastoma and the search for novel treatments

Our research laboratory has a longstanding interest in developmental disorders and embryonic tumors, and recent efforts have focused on the pathogenesis of pediatric liver tumors. This review focuses on hepatoblastoma (HB), the most common pediatric liver malignancy. Despite advances in treatment, patients with metastatic HB have a poor prognosis, and survivors often have permanent side effects attributable to chemotherapy. In an effort to improve survival and lessen long-term complications of HB, we have searched for novel molecular vulnerabilities using a combination of patient derived cell lines, metabolomics, and RNA sequencing of human samples at diagnosis and follow-up. These studies have shed light on pathogenesis and identified putative targets for future therapies in children with advanced HB.

Flubendazole Enhances the Inhibitory Effect of Paclitaxel via HIF1α/PI3K/AKT Signaling Pathways in Breast Cancer

Paclitaxel, a natural anticancer drug, is widely recognized and extensively utilized in the treatment of breast cancer (BC). However, it may lead to certain side effects or drug resistance. Fortunately, combination therapy with another anti-tumor agent has been explored as an option to improve the efficacy of paclitaxel in the treatment of BC. Herein, we first evaluated the synergistic effects of paclitaxel and flubendazole through combination index (CI) calculations. Secondly, flubendazole was demonstrated to synergize paclitaxel-mediated BC cell killing in vitro and in vivo. Moreover, we discovered that flubendazole could reverse the drug resistance of paclitaxel-resistant BC cells. Mechanistically, flubendazole was demonstrated to enhance the inhibitory effect of paclitaxel via HIF1α/PI3K/AKT signaling pathways. Collectively, our findings demonstrate the effectiveness of flubendazole in combination with paclitaxel for treating BC, providing an insight into exploiting more novel combination therapies for BC in the future.

Emerging roles of interactions between ncRNAs and other epigenetic modifications in breast cancer

Up till the present moment, breast cancer is still the leading cause of cancer-related death in women worldwide. Although the treatment methods and protocols for breast cancer are constantly improving, the long-term prognosis of patients is still not optimistic due to the complex heterogeneity of the disease, multi-organ metastasis, chemotherapy and radiotherapy resistance. As a newly discovered class of non-coding RNAs, ncRNAs play an important role in various cancers. Especially in breast cancer, lncRNAs have received extensive attention and have been confirmed to regulate cancer progression through a variety of pathways. Meanwhile, the study of epigenetic modification, including DNA methylation, RNA methylation and histone modification, has developed rapidly in recent years, which has greatly promoted the attention to the important role of non-coding RNAs in breast cancer. In this review, we carefully and comprehensively describe the interactions between several major classes of epigenetic modifications and ncRNAs, as well as their different subsequent biological effects, and discuss their potential for practical clinical applications.

Ipatasertib exhibits anti‑tumorigenic effects and enhances sensitivity to paclitaxel in endometrial cancer in vitro and in vivo

Endometrial cancer is the most common gynecologic cancer and one of the only cancers for which incidence and mortality is steadily increasing. Although curable with surgery in the early stages, endometrial cancer presents a significant clinical challenge in the metastatic and recurrent setting with few novel treatment strategies emerging in the past fifty years. Ipatasertib (IPAT) is an orally bioavailable pan‑AKT inhibitor, which targets all three AKT isoforms and has demonstrated anti‑tumor activity in pre‑clinical models, with clinical trials emerging for many cancer types. In the present study, the MTT assay was employed to evaluate the therapeutic efficacy of IPAT or IPAT in combination with paclitaxel (PTX) in endometrial cancer cell lines and primary cultures of endometrial cancer. The effect of IPAT and PTX on the growth of endometrial tumors was evaluated in a transgenic mouse model of endometrial cancer. Apoptosis was assessed using cleaved caspase assays and cellular stress was assessed using ROS, JC1 and tetramethylrhodamine ethyl ester assays. The protein expression levels of markers of apoptosis and cellular stress, and DNA damage were evaluated using western blotting and immunohistochemistry. IPAT significantly inhibited cell proliferation, caused cell cycle G1 phase arrest, and induced cellular stress and mitochondrial apoptosis in a dose dependent manner in human endometrial cancer cell lines. Combined treatment with low doses of IPAT and PTX led to synergistic inhibition of cell proliferation and induction of cleaved caspase 3 activity in the human endometrial cancer cell lines and the primary cultures. Furthermore, IPAT effectively reduced tumor growth, accompanied by decreased protein expression levels of Ki67 and phosphorylation of S6 in the Lkb1fl/flp53fl/fl mouse model of endometrioid endometrial cancer. The combination of IPAT and PTX resulted in increased expression of phosphorylated‑H2AX and KIF14, markers of DNA damage and microtubule dysfunction respectively, as compared with IPAT alone, PTX alone or placebo‑treated mice. The results of the present study provide a biological rationale to evaluate IPAT and the combination of IPAT and PTX in future clinical trials for endometrial cancer.

Autophagy Alters the Susceptibility of Candida albicans Biofilms to Antifungal Agents

Candida albicans (C. albicans) reigns as a major cause of clinical candidiasis. C. albicans biofilms are known to increase resistance to antifungal agents, making biofilm-related infections particularly challenging to treat. Drug resistance is of particular concern due to the spread of multidrug-resistant fungal pathogens, while autophagy is crucial for the maintenance of cellular homeostasis. Therefore, this study aimed to investigate the effects of an activator and an inhibitor of autophagy on the susceptibility of C. albicans biofilms to antifungal agents and the related mechanisms. The susceptibility of C. albicans biofilms to different antifungal agents after treatment with or without the autophagy activator or inhibitor was evaluated using XTT assay. Alkaline phosphatase (ALP) activity and reactive oxygen species (ROS) level, as well as the expression of ROS-related and autophagy-related genes, were examined to evaluate the autophagic activity of C. albicans biofilms when treated with antifungal agents. The autophagosomes were observed by transmission electron microscopy (TEM). The susceptibility of C. albicans biofilms to antifungal agents changed when autophagy changed. The ALP activity and ROS level of C. albicans biofilms increased with the treatment of antifungal agents, and autophagosomes could be observed in C. albicans biofilms. Autophagy was involved in the susceptibility of C. albicans biofilms to antifungal agents.

Dysregulated Signalling Pathways Driving Anticancer Drug Resistance

One of the leading causes of death worldwide, in both men and women, is cancer. Despite the significant development in therapeutic strategies, the inevitable emergence of drug resistance limits the success and impedes the curative outcome. Intrinsic and acquired resistance are common mechanisms responsible for cancer relapse. Several factors crucially regulate tumourigenesis and resistance, including physical barriers, tumour microenvironment (TME), heterogeneity, genetic and epigenetic alterations, the immune system, tumour burden, growth kinetics and undruggable targets. Moreover, transforming growth factor-beta (TGF-β), Notch, epidermal growth factor receptor (EGFR), integrin-extracellular matrix (ECM), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), phosphoinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR), wingless-related integration site (Wnt/β-catenin), Janus kinase/signal transducers and activators of transcription (JAK/STAT) and RAS/RAF/mitogen-activated protein kinase (MAPK) signalling pathways are some of the key players that have a pivotal role in drug resistance mechanisms. To guide future cancer treatments and improve results, a deeper comprehension of drug resistance pathways is necessary. This review covers both intrinsic and acquired resistance and gives a comprehensive overview of recent research on mechanisms that enable cancer cells to bypass barriers put up by treatments, and, like "satellite navigation", find alternative routes by which to carry on their "journey" to cancer progression.

Impact of AKT1 on cell invasion and radiosensitivity in a triple negative breast cancer cell line developing brain metastasis

Introduction

The PI3K/AKT pathway is activated in 43-70% of breast cancer (BC)-patients and promotes the metastatic potential of BC cells by increasing cell proliferation, invasion and radioresistance. Therefore, AKT1-inhibition in combination with radiotherapy might be an effective treatment option for triple-negative breast cancer (TNBC)-patients with brain metastases.

Methods

The impact of AKT1-knockout (AKT1_KO) and AKT-inhibition using Ipatasertib on MDA-MB-231 BR cells was assessed using in vitro cell proliferation and migration assays. AKT1-knockout in MDA-MB-231BR cells was performed using CRISPR/Cas9. The effect of AKT1-knockout on radiosensitivity of MDA-MB-231BR cell lines was determined via colony formation assays after cell irradiation. To detect genomic variants in AKT1_KO MDA-MB-231BR cells, whole-genome sequencing (WGS) was performed.

Results

Pharmacological inhibition of AKT with the pan-AKT inhibitor Ipatasertib led to a significant reduction of cell viability but did not impact cell migration. Moreover, only MDA-MB-231BR cells were sensitized following Ipatasertib-treatment. Furthermore, specific AKT1-knockout in MDA-MB-231BR showed reduced cell viability in comparison to control cells, with significant effect in one of two analyzed clones. Unexpectedly, AKT1 knockout led to increased cell migration and clonogenic potential in both AKT1_KO clones. RNAseq-analysis revealed the deregulation of CTSO, CYBB, GPR68, CEBPA, ID1, ID4, METTL15, PBX1 and PTGFRN leading to the increased cell migration, higher clonogenic survival and decreased radiosensitivity as a consequence of the AKT1 knockout in MDA-MB-231BR.

Discussion

Collectively, our results demonstrate that Ipatasertib leads to radiosensitization and reduced cell proliferation of MDA-MB-231BR. AKT1-inhibition showed altered gene expression profile leading to modified cell migration, clonogenic survival and radioresistance in MDA-MB-231BR. We conclude, that AKT1-inhibition in combination with radiotherapy contribute to novel treatment strategies for breast cancer brain metastases.

Assessing of programmed cell death gene signature for predicting ovarian cancer prognosis and treatment response

Background

Programmed cell death (PCD) is an overwhelming factor affecting tumor cell metastasis, but the mechanism of PCD in ovarian cancer (OV) is still uncertain.

Methods

To define the molecular subtypes of OV, we performed unsupervised clustering based on the expression level of prognosis related PCD genes in the Cancer Genome Atlas (TCGA)-OV. COX and least absolute shrinkage and selection operator (LASSO) COX analysis were used to identify the OV prognostic related PCD genes, and the genes identified according to the minimum Akaike information criterion (AIC) were the OV prognostic characteristic genes. According to the regression coefficient in the multivariate COX analysis and gene expression data, the Risk Score of OV prognosis was constructed. Kaplan-Meier analysis was conducted to assess the prognostic status of OV patients, and receiver operating characteristic (ROC) curves were conducted to assess the clinical value of Risk Score. Moreover, RNA-Seq date of OV patient derived from Gene Expression Omnibus (GEO, GSE32062) and the International Cancer Genome Consortium (ICGC) database (ICGC-AU), verifying the robustness of the Risk Score via Kaplan-Meier and ROC analysis.Pathway features were performed by gene set enrichment analysis and single sample gene set enrichment analysis. Finally, Risk Score in terms of chemotherapy drug sensitivity and immunotherapy suitability was also evaluated in different groups.

Results

9-gene composition Risk Score system was finally determined by COX and LASSO COX analysis. Patients in the low Risk Score group possessed improved prognostic status, immune activity. PI3K pathway activity was increased in the high Risk Score group. In the chemotherapy drug sensitivity analysis, we found that the high Risk Score group might be more suitable for treatment with PI3K inhibitors Taselisib and Pictilisib. In addition, we found that patients in the low-risk group responded better to immunotherapy.

Conclusion

Risk Score of 9-gene composition of PCD signature possesses promising clinical potential in OV prognosis, immunotherapy, immune microenvironment activity, and chemotherapeutic drug selection, and our study provides the basis for an in-depth investigation of the PCD mechanism in OV.

Recent Update and Drug Target in Molecular and Pharmacological Insights into Autophagy Modulation in Cancer Treatment and Future Progress

Recent evidence suggests that autophagy is a governed catabolic framework enabling the recycling of nutrients from injured organelles and other cellular constituents via a lysosomal breakdown. This mechanism has been associated with the development of various pathologic conditions, including cancer and neurological disorders; however, recently updated studies have indicated that autophagy plays a dual role in cancer, acting as a cytoprotective or cytotoxic mechanism. Numerous preclinical and clinical investigations have shown that inhibiting autophagy enhances an anticancer medicine's effectiveness in various malignancies. Autophagy antagonists, including chloroquine and hydroxychloroquine, have previously been authorized in clinical trials, encouraging the development of medication-combination therapies targeting the autophagic processes for cancer. In this review, we provide an update on the recent research examining the anticancer efficacy of combining drugs that activate cytoprotective autophagy with autophagy inhibitors. Additionally, we highlight the difficulties and progress toward using cytoprotective autophagy targeting as a cancer treatment strategy. Importantly, we must enable the use of suitable autophagy inhibitors and coadministration delivery systems in conjunction with anticancer agents. Therefore, this review briefly summarizes the general molecular process behind autophagy and its bifunctional role that is important in cancer suppression and in encouraging tumor growth and resistance to chemotherapy and metastasis regulation. We then emphasize how autophagy and cancer cells interacting with one another is a promising therapeutic target in cancer treatment.

Effects of chloroquine and hydroxychloroquine on the sensitivity of pancreatic cancer cells to targeted therapies

Approaches to improve pancreatic cancer therapy are essential as this disease has a very bleak outcome. Approximately 80% of pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). PDAC is a cancer which is difficult to effectively treat as it is often detected late in the disease process. Almost all PDACs (over 90%) have activating mutations in the GTPase gene KRAS. These mutations result in constitutive KRas activation and the mobilization of downstream pathways such as the Raf/MEK/ERK pathway. Small molecule inhibitors of key components of the KRas/Raf/MEK/ERK pathways as well as monoclonal antibodies (MoAbs) specific for upstream growth factor receptors such insulin like growth factor-1 receptor (IGF1-R) and epidermal growth factor receptors (EGFRs) have been developed and have been evaluated in clinical trials. An additional key regulatory gene frequently mutated (∼75%) in PDAC is the TP53 tumor suppressor gene which controls the transcription of multiple genes involved in cell cycle progression, apoptosis, metabolism, cancer progression and other growth regulatory processes. Small molecule mutant TP53 reactivators have been developed which alter the structure of mutant TP53 protein and restore some of its antiproliferative activities. Some mutant TP53 reactivators have been examined in clinical trials with patients with mutant TP53 genes. Inhibitors to the TP53 negative regulator Mouse Double Minute 2 (MDM2) have been developed and analyzed in clinical trials. Chloroquine and hydroxychloroquine are established anti-malarial and anti-inflammatory drugs that also prevent the induction of autophagy which can have effects on cancer survival. Chloroquine and hydroxychloroquine have also been examined in various clinical trials. Recent studies are suggesting effective treatment of PDAC patients may require chemotherapy as well as targeting multiple pathways and biochemical processes.