Oroxylin A reverses hypoxia-induced cisplatin resistance through inhibiting HIF-1α mediated XPC transcription

Flavonoids in the Treatment of Non-small Cell Lung Cancer via Immunomodulation: Progress to Date

Lung cancer is one of the most common malignancies in the world, while non-small cell lung cancer (NSCLC) accounts for about 80% of all lung cancers. Most patients with NSCLC have advanced stage disease at diagnosis, and the 5-year survival rate can be discouragingly low. Flavonoids are widely found in fruits, vegetables, teas, and medicinal plants, with a variety of functional effects, including anti-inflammatory, antioxidant, and anticancer properties. This review aims to focus on the research progress of flavonoids in the treatment of NSCLC, including immunomodulatory effects on NSCLC, promotion of reactive oxygen species (ROS) production, interaction with microRNA (miRNA), and interactions with certain proteins. In addition, combining flavonoids and anticancer agents, radiotherapy, or nanoparticles can reverse NSCLC  drug resistance, inducing apoptosis of cancer cells. It therefore appears that flavonoids alone or in combination with other treatment agents may be a promising therapeutic modality for treating NSCLC, with great potential in mass production and clinical applications.

HIF-1α-induced long noncoding RNA LINC02776 promotes drug resistance of ovarian cancer by increasing polyADP-ribosylation

BACKGROUND

Chemoresistance remains a major hurdle in ovarian cancer (OC) treatment, as many patients eventually develop resistance to platinum-based chemotherapy and/or PARP inhibitors (PARPi).

METHODS

We performed transcriptome-wide analysis by RNA sequencing (RNA-seq) data of platinum-resistant and -sensitive OC tissues. We demonstrated the role of LINC02776 in platinum resistance in OC cells, mice models and patient-derived organoid (PDO) models.

RESULTS

We identify the long noncoding RNA LINC02776 as a critical factor of platinum resistance. Elevated expression of LINC02776 is observed in platinum-resistant OC and serves as an independent prognostic factor for OC patients. Functionally, silencing LINC02776 reduces proliferation and DNA damage repair in OC cells, thereby enhancing sensitivity to platinum and PARPi in both xenograft mouse models and patient-derived organoid (PDO) models with acquired chemoresistance. Mechanistically, LINC02776 binds to the catalytic domain of poly (ADP-ribose) polymerase 1 (PARP1), promoting PARP1-dependent polyADP-ribosylation (PARylation) and facilitating homologous recombination (HR) restoration. Additionally, high HIF-1α expression in platinum-resistant tissues further stimulates LINC02776 transcription.

CONCLUSIONS

Our findings suggest that targeting LINC02776 represents a promising therapeutic strategy for OC patients who have developed resistance to platinum or PARPi.

KEY POINTS

LINC02776 promotes OC cell proliferation by regulating DNA damage and apoptosis signaling pathways. LINC02776 binds PARP1 to promote DNA damage-triggered PARylation in OC cells. LINC02776 mediates cisplatin and olaparib resistance in OC cells by enhancing PARP1-mediated PARylation activity and regulating the PARP1-mediated HR pathway. The high expression of LINC02776 is induced by HIF-1α in platinum-resistant OC cells and tissues.

Traditional Chinese medicine in lung cancer treatment

Lung cancer remains a major global health challenge and one of the leading causes of cancer-related deaths worldwide. Despite significant advancements in treatment, challenges such as drug resistance, side effects, metastasis and recurrence continue to impact patient outcomes and quality of life. In response, there is growing interest in complementary and integrative approaches to cancer care. Traditional Chinese medicine (TCM), with its long history, abundant clinical experience, holistic perspective and individualized approach, has garnered increasing attention for its role in lung cancer prevention and management. This review provides a comprehensive overview of the advances in TCM for lung cancer treatment, covering its theoretical foundation, treatment principles, clinical experiences and evidence supporting its efficacy. We also provide a systematic summary of the preclinical mechanisms, through which TCM impacts lung cancer, including the induction of cell death, reversal of drug resistance, inhibition of metastasis and modulation of immune responses. Additionally, future prospects for TCM in lung cancer treatment are discussed, offering insights into its expanded application and integration with modern medicine to address this challenging disease.

Combination of Vitex pseudo-negundo methanolic-extract with cisplatin can induce antioxidant activity and apoptosis in HeLa and Caski cells

Background

Cisplatin-based chemotherapy as a common therapeutic regimen for cervical cancer patients, is becoming more and more ineffective due to high resistance. This urges the need for introducing novel metabolics such as botanical drugs with the capacity to increase the cisplatin effectiveness. In that regard, here we investigated the anticancer effects of the Cisplatin-Vitex pseudo-Negundo combination in cervical cancer cell lines.

Method and Material

V. pseudo-Negundo fruits were dried and extracted methanolic fraction. The MTT assay was performed to evaluate cytotoxicity of both drugs in CaSki and HeLa cells. Then, apoptosis, ROS production, and cell cycling were assessed by flow cytometry assay in cells treated with V. pseudo-Negundo and Cisplatin and their combination. Also, the rate of cell migration and colony formation were measured, using wound healing and colony formation assay, respectively. Also, the expression level of related genes (CD133, BAX, BCL2, Casp-3/8/9, MMP-3) was evaluated using the RT-PCR method.

Results

The obtained results established that the V. pseudo-Negundo plant has medicinal properties to induce apoptotic and antioxidant signals. The combination treatment of methanol extraction and Cisplatin had a cytotoxic effect on cervical cancer cell lines (HeLa and CaSki) compared to monotherapy. Also, combination therapy resulted in an increased apoptosis rate and diminished ROS production in both CaSki and HeLa cell lines. Furthermore, V. pseudo-Negundo and Cisplatin combination therapy leads to cell cycle arrest in the G2-M and G0-G1 phase in HeLa and CaSki cell lines, respectively. Moreover, combination therapy decreased the colony formation and cell motility in both cell lines and upregulated caspases gene expression.

Conclusion

The combination of V. pseudo-Negundo with Cisplatin therapy results in a significant anti-cancer and antioxidant effect compared to cisplatin, representing a promising candidate for future clinical investigations.

Efficacy of Oroxylin A in ameliorating renal fibrosis with emphasis on Sirt1 activation and TGF-β/Smad3 pathway modulation

Introduction

Renal fibrosis poses a serious threat to human health. At present, there are few types of traditional Chinese medicine used to treat this disease, and Oroxylin A (OA), as a natural product with multiple biological activities, is expected to be used for the treatment of renal fibrosis.

Methods

The tolerance of osteoarthritis and its impact on renal fibrosis were studied through ADMET, Lipinski's filter, establishment of a unilateral ureteral obstruction (UUO) model, and molecular docking.

Results

OA has good drug tolerance. Compared with the sham group, UUO mice that did not receive OA treatment showed severe tubular dilation and atrophy, extracellular matrix (ECM) deposition, and inflammatory cell infiltration in their kidneys, while OA-treated mice showed significant improvement in these symptoms. OA treatment remarkably restrained the accumulation of fibronectin and α-SMA. Moreover, OA treatment remarkably decreased the abnormal upregulation of inflammatory factors (IL-1β, IL-6, and TNF-α) in the obstructed kidney of UUO mice. Sirtuin1 (Sirt1) expression was markedly diminished in the kidneys of UUO mice and TGF-β1-induced HK-2 cells, whereas this reduction was largely reversed after OA treatment. The results support that OA exerts antifibrotic effects partly through the promotion of the activity of Sirt1. In in vitro results, OA treatment markedly inhibited the activation of Smad3 in UUO mice, thereby ameliorating renal fibrosis. OA could form hydrogen bonds with key the amino acid ASN226 in Sirt1, thereby activating Sirt1, which might also be the reason why OA could resist renal fibrosis.

Discussion

Our study indicated that OA might exert anti-renal fibrosis effects through the activation of Sirt1 and the suppression of the TGF-β/Smad3 signaling pathway.

Oroxylin A-induced Trained Immunity Promotes LC3-associated Phagocytosis in Macrophage in Protecting Mice Against Sepsis

Sepsis is defined as a dysregulated host response to infection that leads to multiorgan failure. Innate immune memory, i.e., "trained immunity", can result in stronger immune responses and provide protection against various infections. Many biological agents, including β-glucan, can induce trained immunity, but these stimuli may cause uncontrolled inflammation. Oroxylin A (OA) is an active flavonoid compound that is derived from Scutellaria baicalensis. OA is an agonist for inducing trained immunity in vivo and in vitro, and β-glucan was used as a positive control. The protective effects of OA-induced trained immunity were evaluated in mouse models that were established by either lipopolysaccharide (LPS) administration or caecal ligation and puncture (CLP). The expression of inflammatory factors and signaling pathway components involved in trained immunity was evaluated in vitro using qRT‒PCR, western blotting (WB) and enzyme-linked immunosorbent assay (ELISA). Flow cytometry and confocal microscopy were used to examine reactive oxygen species (ROS) levels and phagocytosis in trained macrophages. A PCR array was used to screen genes that were differentially expressed in trained macrophages. Here, we revealed that OA alleviated sepsis via trained immunity. OA-treated macrophages displayed increased glycolysis and mTOR phosphorylation, and mTOR inhibitors suppressed OA-induced trained immunity by effectively reprogramming macrophages. The PCR array revealed key genes in the mTOR signaling pathway in OA-treated macrophages. Furthermore, OA targeted the Dectin-1-syk axis to promote LC3-associated phagocytosis (LAP) by trained macrophages, thereby enhancing the ability of these macrophages to protect against infection. This ability could be transferred to a new host via the adoptive transfer of peritoneal macrophages. This study is the first to provide new insights into the potential of OA-induced trained immunity to be used as a strategy to protect mice against sepsis by promoting LAP by macrophages.

Hydrochlorothiazide disrupts DNA damage response to exacerbate skin photosensitivity

Hydrochlorothiazide (HCTZ) is a widely utilized diuretic for the treatment of hypertension. The photosensitivity of HCTZ has been recognized for six decades, with UVA being considered the primary culprit. However, the precise molecular mechanism of HCTZ sensitizing skin to UV radiation remains unknown. In this study, we demonstrate that HCTZ exacerbates UVB-induced photosensitivity in normal skin by disrupting the DNA damage response, a crucial network responsible for maintaining epidermal homeostasis. Here, we found that HCTZ aggravates UVB-induced mouse skin damage. Through transcriptomic and proteomic profiling, we have found that the cell cycle and p53 signaling pathway may contribute to the photosensitivity caused by HCTZ. In keratinocytes, HCTZ promotes the transition from G1 to S phase and inhibits the p53 signaling pathway after exposure to UV radiation. We have found that HCTZ enhances the accumulation of DNA damage induced by UVB and impairs nucleotide excision repair (NER), which is responsible for repairing UVB-induced DNA lesions, by inhibiting the expression of NER-related genes and shortening the duration of G1 phase. Furthermore, pharmacologically inducing G1 arrest eliminates HCTZ-induced accumulation of damaged DNA. These findings unveil an unknown mechanism through which HCTZ impairs NER and interferes with UVB-induced cell cycle arrest, ultimately leading to improper response towards DNA damage and increased skin sensitivity.

Cellular and molecular mechanisms of oroxylin A in cancer therapy: Recent advances

Seeking an effective and safe scheme is the common goal of clinical treatment of tumor patients. In recent years, traditional Chinese medicine has attracted more and more attention in order to discover new drugs with good anti-tumor effects. Oroxylin A (OA) is a compound found in natural Oroxylum indicum and Scutellaria baicalensis Georgi plants and has been used in the treatment of various cancers. Studies have shown that OA has a wide range of powerful biological activities and plays an important role in neuroprotection, anti-inflammation, anti-virus, anti-allergy, anti-tumor and so on. OA shows high efficacy in tumor treatment. Therefore, it has attracted great attention of researchers all over the world. This review aims to discuss the anti-tumor effects of OA from the aspects of cell cycle arrest, induction of cell proliferation and apoptosis, induction of autophagy, anti-inflammation, inhibition of glycolysis, angiogenesis, invasion, metastasis and reversal of drug resistance. In addition, the safety and toxicity of the compound were also discussed. As a next step, to clarify the benefits and adverse effects of Oroxylin A in cancer patients further experiments, especially clinical trials, are needed.

Hypoxia-inducible factor in cancer: from pathway regulation to therapeutic opportunity

Cancer remains one of the most formidable challenges in modern medicine, due to its complex and dynamic nature, which demands innovative therapeutic approaches. One major challenge to cancer treatment is the tumour microenvironment and in particular tumour hypoxia (low oxygen levels), which contributes to tumour progression and immune evasion. At the cellular level, this is primarily governed by hypoxia-inducible factor (HIF). HIF is a transcription factor that orchestrates cellular responses to low oxygen levels, driving angiogenesis, metabolic adaptation and immune regulation. HIF's dysregulation is frequently observed in various cancer types and correlates with increased aggressiveness, metastasis, resistance to therapy and poor patient prognosis. Consequently, understanding the cellular mechanisms underlying HIF activation and its downstream effects has become crucial to developing targeted cancer therapies for improving cancer patient outcomes and represents a key step towards precision medicine. Recent advancements in drug development have led to the emergence of HIF inhibitors, which aim to disrupt HIF-driven processes in cancer providing therapeutic benefit. Here, we provide a review of the molecular mechanisms through which HIF promotes tumour growth and resistance, emphasising the potential clinical benefits of HIF-targeted therapies. This review will discuss the challenges and opportunities associated with translating HIF inhibition into clinical practice, including ongoing clinical trials and future directions in the development of HIF-based cancer treatments.

Nanomedicine Strategies in Conquering and Utilizing the Cancer Hypoxia Environment

Cancer with a complex pathological process is a major disease to human welfare. Due to the imbalance between oxygen (O2) supply and consumption, hypoxia is a natural characteristic of most solid tumors and an important obstacle for cancer therapy, which is closely related to tumor proliferation, metastasis, and invasion. Various strategies to exploit the feature of tumor hypoxia have been developed in the past decade, which can be used to alleviate tumor hypoxia, or utilize the hypoxia for targeted delivery and diagnostic imaging. The strategies to alleviate tumor hypoxia include delivering O2, in situ O2 generation, reprogramming the tumor vascular system, decreasing O2 consumption, and inhibiting HIF-1 related pathways. On the other side, hypoxia can also be utilized for hypoxia-responsive chemical construction and hypoxia-active prodrug-based strategies. Taking advantage of hypoxia in the tumor region, a number of methods have been applied to identify and keep track of changes in tumor hypoxia. Herein, we thoroughly review the recent progress of nanomedicine strategies in both conquering and utilizing hypoxia to combat cancer and put forward the prospect of emerging nanomaterials for future clinical transformation, which hopes to provide perspectives in nanomaterials design.

Natural medicinal compounds target signal transduction pathways to overcome ABC drug efflux transporter-mediated multidrug resistance in cancer

ATP-binding cassette (ABC) transporters such as ABCB1, ABCG2, and ABCC1 are the major players in drug efflux-mediated multidrug resistance (MDR), which severely affects the efficacy of chemotherapy. Several synthetic compounds block the drug transport by ABC transporters; however, they exhibit a narrow therapeutic window, and produce side effects in non-target normal tissues. Conversely, the downregulation of the expression of ABC drug transporters seems to be a promising strategy to reverse MDR in cancer cells. Several signaling pathways, such as NF-κB, STAT3, Gli, NICD, YAP/TAZ, and Nrf2 upregulate the expression of ABC drug transporters in drug-resistant cancers. Recently, natural medicinal compounds have gained importance to overcome the ABC drug-efflux pump-mediated MDR in cancer. These compounds target transcription factors and the associated signal transduction pathways, thereby downregulating the expression of ABC transporters in drug-resistant cancer cells. Several potent natural compounds have been identified as lead candidates to synergistically enhance chemotherapeutic efficacy, and a few of them are already in clinical trials. Therefore, modulation of signal transduction pathways using natural medicinal compounds for the reversal of ABC drug transporter-mediated MDR in cancer is a novel approach for improving the efficiency of the existing chemotherapeutics. In this review, we discuss the modulatory role of natural medicinal compounds on cellular signaling pathways that regulate the expression of ABC transporters in drug-resistant cancer cells.

Bioinformatics-based analysis reveals elevated CYTL1 as a potential therapeutic target for BRAF-mutated melanoma

Introduction: Despite many recent emerging therapeutic modalities that have prolonged the survival of melanoma patients, the prognosis of melanoma remains discouraging, and further understanding of the mechanisms underlying melanoma progression is needed. Melanoma patients often have multiple genetic mutations, with BRAF mutations being the most common. In this study, public databases were exploited to explore a potential therapeutic target for BRAF-mutated melanoma. Methods: In this study, we analyzed differentially expressed genes (DEGs) in normal tissues and melanomas, Braf wild-type and Braf mutant melanomas using information from TCGA databases and the GEO database. Subsequently, we analyzed the differential expression of CYTL1 in various tumor tissues and its effect on melanoma prognosis, and resolved the mutation status of CYTL1 and its related signalling pathways. By knocking down CYTL1 in melanoma cells, the effects of CYTL1 on melanoma cell proliferation, migration and invasion were further examined by CCK8 assay, Transwell assay and cell migration assay. Results: 24 overlapping genes were identified by analyzing DEGs common to melanoma and normal tissue, BRAF-mutated and BRAF wild-type melanoma. Among them, CYTL1 was highly expressed in melanoma, especially in BRAF-mutated melanoma, and the high expression of CYTL1 was associated with epithelial-mesenchymal transition (EMT), cell cycle, and cellular response to UV. In melanoma patients, especially BRAF-mutated melanoma patients, clinical studies showed a positive correlation between increased CYTL1 expression and shorter overall survival (OS) and disease-free survival (DFS). In vitro experiments further confirmed that the knockdown of CYTL1 significantly inhibited the migration and invasive ability of melanoma cells. Conclusion: CYTL1 is a valuable prognostic biomarker and a potentially effective therapeutic target in melanoma, especially BRAF-mutated melanoma.

Novel cancer treatment paradigm targeting hypoxia-induced factor in conjunction with current therapies to overcome resistance

Chemotherapy, radiotherapy, targeted therapy, and immunotherapy are established cancer treatment modalities that are widely used due to their demonstrated efficacy against tumors and favorable safety profiles or tolerability. Nevertheless, treatment resistance continues to be one of the most pressing unsolved conundrums in cancer treatment. Hypoxia-inducible factors (HIFs) are a family of transcription factors that regulate cellular responses to hypoxia by activating genes involved in various adaptations, including erythropoiesis, glucose metabolism, angiogenesis, cell proliferation, and apoptosis. Despite this critical function, overexpression of HIFs has been observed in numerous cancers, leading to resistance to therapy and disease progression. In recent years, much effort has been poured into developing innovative cancer treatments that target the HIF pathway. Combining HIF inhibitors with current cancer therapies to increase anti-tumor activity and diminish treatment resistance is one strategy for combating therapeutic resistance. This review focuses on how HIF inhibitors could be applied in conjunction with current cancer treatments, including those now being evaluated in clinical trials, to usher in a new era of cancer therapy.

Anticancer potential of oroxylin A: from mechanistic insight to synergistic perspectives

Oroxylin A (OA), a well-known constituent of the root of Scutellariae plants, has been used in ethnomedicine already for centuries in treating various neoplastic disorders. However, only recent molecular studies have revealed the different mechanisms behind its action, demonstrating antiproliferative, anti-inflammatory, and proapoptotic effects, restricting also the spread of cancer cells to distant organs. A variety of cellular targets and modulated signal transduction pathways regulated by OA have been determined in diverse cells derived from different malignant tissues. In this review article, these anticancer activities are thoroughly described, representing OA as a potential lead structure for the design of novel more potent anticancer medicines. In addition, co-effects of this natural compound with conventional anticancer agents are analyzed and the advantages provided by nanotechnological methods for more efficient application of OA are discussed. In this way, OA might represent an excellent example of using ethnopharmacological knowledge for designing modern medicines.

Traditional Chinese Medicine has great potential as candidate drugs for lung cancer: A review

ETHNOPHARMACOLOGICAL RELEVANCE

With high mortality and morbidity rates, lung cancer (LC) has become one of the major threats to human health. The treatment strategies for LC currently face issues, such as drug resistance and body tolerance. Traditional Chinese medicine (TCM) is characterized by novel pharmacological mechanisms, low toxicity, and limited side effects. TCM includes a substantial number of biologically active ingredients, several of which are effective monomeric agents against LC. An increasing number of researchers are focusing their efforts on the discovery of active anti-cancer ingredients in TCM.

AIM OF THE REVIEW

In this review, we summarized the anti-LC mechanisms of five types of TCM monomeric compounds. Our goal is to provide research ideas for the identification of new prospective medication candidates for the treatment of LC.

MATERIALS AND METHODS

We collected reports on the anti-LC effects of TCM monomers from web databases, including PubMed, Science Direct, Web of Science, and Europe PubMed Central. Among the keywords used were "lung cancer," "traditional Chinese medicine," "pharmacology," and their combinations thereof. Then, we systematically summarized the anti-LC efficacy and related mechanisms of TCM monomers.

RESULTS

Based on the available literature, this paper reviewed the therapeutic effects and mechanisms of five types of TCM monomers on LC. The characteristics of TCM monomers include the capabilities to suppress the tumor cell cycle, inhibit proliferation, induce apoptosis, promote autophagy, inhibit tumor cell invasion and metastasis, and enhance efficacy or reduce drug resistance when combined with cytotoxic agents and other methods to arrest the progression of LC and prolong the survival of patients.

CONCLUSIONS

TCM contains numerous flavonoids, alkaloids, terpenoids, polyphenols, and other active compounds that are effective against LC. Given their chemical structure and pharmacological properties, these monomers are suitable as candidate drugs for the treatment of LC.

Modulation of diverse oncogenic signaling pathways by oroxylin A: An important strategy for both cancer prevention and treatment

BACKGROUND

Regardless of major advances in diagnosis, prevention and treatment strategies, cancer is still a foreboding cause due to factors like chemoresistance, radioresistance, adverse side effects and cancer recurrence. Therefore, continuous development of unconventional approaches is a prerequisite to overcome foregoing glitches. Natural products have found their way into treatment of serious health conditions, including cancer since ancient times. The compound oroxylin A (OA) is one among those with enormous potential against different malignancies. It is a flavonoid obtained from the several plants such as Oroxylum indicum, Scutellaria baicalensis and S. lateriflora, Anchietea pyrifolia, and Aster himalaicus.

PURPOSE

The main purpose of this study is to comprehensively elucidate the anticancerous effects of OA against various malignancies and unravel their chemosensitization and radiosensitization potential. Pharmacokinetic and pharmacodynamic studies of OA have also been investigated.

METHOD

The literature on antineoplastic effects of OA was searched in PubMed and Scopus, including in vitro and in vivo studies and is summarized based on a systematic review protocol prepared according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The term "oroxylin A" was used in combination with "cancer" and all the title, abstracts and keywords appeared were considered.

RESULTS

In Scopus, a total of 157 articles appeared out of which 103 articles that did not meet the eligibility criteria were eliminated and 54 were critically evaluated. In PubMed, from the 85 results obtained, 26 articles were eliminated and 59 were included in the preparation of this review. Mounting number of studies have illustrated the anticancer effects of OA, and its mechanism of action.

CONCLUSION

OA is a promising natural flavonoid possessing wide range of pleiotropic properties and is a potential anticancer agent. It has a great potential in the treatment of multiple cancers including brain, breast, cervical, colon, esophageal, gall bladder, gastric, hematological, liver, lung, oral, ovarian, pancreatic and skin. However, lack of pharmacokinetic studies, toxicity assessments, and dose standardization studies and adverse effects limit the optimization of this compound as a therapeutic agent.

Silencing TRPM2 enhanced erastin- and RSL3-induced ferroptosis in gastric cancer cells through destabilizing HIF-1α and Nrf2 proteins

Ferroptosis is a regulated form of cell death driven by small molecules or conditions that induce lipid-based reactive oxygen species (ROS) accumulation. Cation channel transient receptor potential melastatin-2 (TRPM2) is crucial for cancer cell survival. Our bioinformatic analysis revealed that TRPM2 is associated with cellular responses to chemical stimulus and oxidative stress, implying the potential role of TRPM2 in ferroptosis. Gastric cancer cells were treated with the ferroptosis-inducer, Erastin and RSL3. siRNA transfection was used to silence TRPM2. The levels of GSH, Fe2+, ROS and lipid peroxidation, and the activity of GPx activity were evaluated by flow cytometry and spectrophotometer. The effect of TRPM2 on ubiquitination of HIF-1α and Nrf2 were evaluated by co-immunoprecipitation. Erastin and RSL3 induced the up-regulation of TRPM2 in gastric cancer cell lines, especially in SGC7901 and MGC803. These two cells also showed stronger resistance to Erastin and RSL3 than the other cell lines. TRPM2 knockdown reduced the concentration of GSH and GPx activity, but enhanced the concentration of Fe2+, ROS and lipid peroxidation, which are significant indicators of ferroptosis. Importantly, silencing TRPM2 enhanced the inhibitory effects of Erastin and RSL3 on gastric cancer cell viability, migration, and invasion. TRPM2 stabilized and finally elevated the abundance of HIF-1α and Nrf2 in SGC7901 and MGC803 cells upon Erastin and RSL3. Activation of HIF-1α impaired Erastin- and RSL3-induced ferroptosis after TRPM2 knockdown. Collectively, silencing TRPM2 enhanced Erastin- and RSL3-induced ferroptosis in gastric cancer cells through destabilizing HIF-1α and Nrf2 proteins.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-022-00545-z.

Oroxylin A: A Promising Flavonoid for Prevention and Treatment of Chronic Diseases

There have been magnificent advancements in the understanding of molecular mechanisms of chronic diseases over the past several years, but these diseases continue to be a considerable cause of death worldwide. Most of the approved medications available for the prevention and treatment of these diseases target only a single gene/protein/pathway and are known to cause severe side effects and are less effective than they are anticipated. Consequently, the development of finer therapeutics that outshine the existing ones is far-reaching. Natural compounds have enormous applications in curbing several disastrous and fatal diseases. Oroxylin A (OA) is a flavonoid obtained from the plants Oroxylum indicum, Scutellaria baicalensis, and S. lateriflora, which have distinctive pharmacological properties. OA modulates the important signaling pathways, including NF-κB, MAPK, ERK1/2, Wnt/β-catenin, PTEN/PI3K/Akt, and signaling molecules, such as TNF-α, TGF-β, MMPs, VEGF, interleukins, Bcl-2, caspases, HIF-1α, EMT proteins, Nrf-2, etc., which play a pivotal role in the molecular mechanism of chronic diseases. Overwhelming pieces of evidence expound on the anti-inflammatory, anti-bacterial, anti-viral, and anti-cancer potentials of this flavonoid, which makes it an engrossing compound for research. Numerous preclinical and clinical studies also displayed the promising potential of OA against cancer, cardiovascular diseases, inflammation, neurological disorders, rheumatoid arthritis, osteoarthritis, etc. Therefore, the current review focuses on delineating the role of OA in combating different chronic diseases and highlighting the intrinsic molecular mechanisms of its action.

Eukaryotic initiation factor 5A2 mediates hypoxia-induced autophagy and cisplatin resistance

Hypoxia-induced cisplatin resistance is a major challenge during non-small cell lung cancer (NSCLC) treatment. Based on previous studies, we further explored the effect of eukaryotic initiation factor 5A2 (eIF5A2) in hypoxia-induced cisplatin resistance. In this study, we found that autophagy and cisplatin resistance were increased under hypoxic conditions in three different NSCLC cell lines. Compared with that under normoxic conditions, dramatic upregulation of eIF5A2 and hypoxia inducible factor 1 subunit alpha (HIF-1α) levels were detected under hypoxia exposure. Small interfering RNA silencing of HIF-1α resulted in decreased expression of eIF5A2, indicating that eIF5A2 acts downstream of HIF-1α. In addition, the expression of eIF5A2 was significantly higher in NSCLC tumors compared with that in normal tissues. RNA silencing-mediated downregulation of eIF5A2 decreased hypoxia-induced autophagy, thereby reducing hypoxia-induced cisplatin resistance in NSCLC cells. The roles of eIF5A2 in cisplatin resistance were further validated in vivo. Combined treatment using eIF5A2-targeted downregulation together with cisplatin significantly inhibited tumor growth compared with cisplatin alone in the subcutaneous mouse model. In conclusions, eIF5A2 overexpression is involved in hypoxia-induced autophagy during cisplatin resistance. We suggest that a combination of eIF5A2 targeted therapy and cisplatin chemotherapy is probably an effective strategy to reverse hypoxia-induced cisplatin resistance and inhibit NSCLC development.

Phytochemical Profiling and Bio-Potentiality of Genus Scutellaria: Biomedical Approach

Scutellaria (Lamiaceae) comprises over 360 species. Based on its morphological structure of calyx, also known as Skullcap, it is herbaceous by habit and cosmopolitan by habitat. The species of Scutellaria are widely used in local communities as a natural remedy. The genus contributed over three hundred bioactive compounds mainly represented by flavonoids and phenols, chemical ingredients which serve as potential candidates for the therapy of various biological activities. Thus, the current review is an attempt to highlight the biological significance and its correlation to various isolated bioactive ingredients including flavonoids, terpenoids, phenols, alkaloids, and steroids. However, flavonoids were the dominant group observed. The findings of the Scutellaria reveal that due to its affluent basis of numerous chemical ingredients it has a diverse range of pharmacological potentials, such as antimicrobial, antioxidant, antifeedant, enzyme inhibition, anti-inflammatory, and analgesic significance. Currently, various bioactive ingredients have been investigated for various biological activities from the genus Scutellaria in vitro and in vivo. Furthermore, these data help us to highlight its biomedical application and to isolate the responsible compounds to produce innovative medications as an alternative to synthetic drugs.

Hypoxia Promotes Glioma Stem Cell Proliferation by Enhancing the 14-3-3β Expression via the PI3K Pathway

Glioma is a serious fatal type of cancer with the shorter median survival period and poor quality of living. The overall 5-year survival rate remains low due to high recurrence rates. Glioma stem cells (GSCs) play the important roles in the development of gliomas. Examination of the numerous biomarkers or cancer-associated genes involved in the development or prevention of glioma may therefore serve the discovery of novel strategies to treat patients with glioma. Hypoxia induced by using CoCl2 application and 14-3-3β protein knockdown by specific small interfering RNA transfection were performed in GSCs both in vitro and in vivo to observe their role in glioma progression and metastasis occurrence by using western blot analysis and MTT assay. The results demonstrated that CoCl2 application enhanced the 14-3-3β protein expression and mRNA levels via the PI3K pathway in GSCs. Furthermore, hypoxia promoted GSC cell proliferation and activated the expression of proliferating cell nuclear antigen, which was inhibited following 14-3-3β knockdown. In addition, tumor growth in mice was enhanced by CoCl2 application but reversed following 14-3-3β knockdown, which also enhanced GSC cell apoptosis. In conclusion, the present study demonstrated that hypoxia promoted glioma growth both in vitro and in vivo by increasing the 14-3-3β expression via the PI3K signaling pathway. 14-3-3β and HIF-1α may therefore be considered as the potential therapeutic target to treat patients with glioma.

Perftoran® Inhibits Hypoxia-Associated Resistance in Lung Cancer Cells to Carboplatin

Perftoran^® (perfluorodecalin) is an oxygen carrier, and carboplatin is a common chemotherapy drug used worldwide for lung cancer treatment. Hypoxia is one of the factors that induce resistance of lung cancer cells to carboplatin. This study explored the role of Perftoran^®, as an oxygen carrier, in lowering the resistance of lung cancer cells to carboplatin through suppression of hypoxia pathway mediators. The effect of Perftoran^® on the resistance of human lung cancer A549 cells to carboplatin was investigated through the evaluation of cytotoxicity by MTT, cell death mode by dual DNA staining, DNA damage by comet assay, DNA platination (DNA/carboplatin adducts) by atomic absorption spectroscopy, hypoxia degree by pimonidazole, HIF-1α/HIF-2α concentrations by ELISA, expression of miRNAs (hypoxamiRs miR-210, miR-21, and miR-181a) by qRT-PCR, and the content of drug resistance transporter MRP-2 by immunocytochemical staining. Results indicated that compared to carboplatin, Perftoran^®/carboplatin decreased cell resistance to carboplatin by potentiating its cytotoxicity using only 45% of carboplatin IC₅₀ and inducing apoptosis. Perftoran^® induced DNA platination and DNA damage index in cells compared to carboplatin alone. Moreover, compared to treatment with carboplatin alone, co-treatment of cells with Perftoran^® and carboplatin inhibited cellular pimonidazole hypoxia adducts, diminished HIF-1α/HIF-2α concentrations, suppressed hypoxamiR expression, and decreased MRP-2. In conclusion, Perftoran^® inhibited resistance of lung cancer cells to carboplatin through the inhibition of both hypoxia pathway mediators and the drug resistance transporter MRP-2 and through the induction of DNA/carboplatin adduct formation.

Pharmacological Effects of Cisplatin Combination with Natural Products in Cancer Chemotherapy

Cisplatin and other platinum-based drugs, such as carboplatin, ormaplatin, and oxaliplatin, have been widely used to treat a multitude of human cancers. However, a considerable proportion of patients often relapse due to drug resistance and/or toxicity to multiple organs including the liver, kidneys, gastrointestinal tract, and the cardiovascular, hematologic, and nervous systems. In this study, we sought to provide a comprehensive review of the current state of the science highlighting the use of cisplatin in cancer therapy, with a special emphasis on its molecular mechanisms of action, and treatment modalities including the combination therapy with natural products. Hence, we searched the literature using various scientific databases., such as MEDLINE, PubMed, Google Scholar, and relevant sources, to collect and review relevant publications on cisplatin, natural products, combination therapy, uses in cancer treatment, modes of action, and therapeutic strategies. Our search results revealed that new strategic approaches for cancer treatment, including the combination therapy of cisplatin and natural products, have been evaluated with some degree of success. Scientific evidence from both in vitro and in vivo studies demonstrates that many medicinal plants contain bioactive compounds that are promising candidates for the treatment of human diseases, and therefore represent an excellent source for drug discovery. In preclinical studies, it has been demonstrated that natural products not only enhance the therapeutic activity of cisplatin but also attenuate its chemotherapy-induced toxicity. Many experimental studies have also reported that natural products exert their therapeutic action by triggering apoptosis through modulation of mitogen-activated protein kinase (MAPK) and p53 signal transduction pathways and enhancement of cisplatin chemosensitivity. Furthermore, natural products protect against cisplatin-induced organ toxicity by modulating several gene transcription factors and inducing cell death through apoptosis and/or necrosis. In addition, formulations of cisplatin with polymeric, lipid, inorganic, and carbon-based nano-drug delivery systems have been found to delay drug release, prolong half-life, and reduce systemic toxicity while other formulations, such as nanocapsules, nanogels, and hydrogels, have been reported to enhance cell penetration, target cancer cells, and inhibit tumor progression.

Escape From Cisplatin-Induced Senescence of Hypoxic Lung Cancer Cells Can Be Overcome by Hydroxychloroquine

Chemotherapy is the commonly used treatment for advanced lung cancer. However, it produces side effects such as the development of chemoresistance. A possible responsible mechanism may be therapy-induced senescence (TIS). TIS cells display increased senescence-associated β-galactosidase (SA-β-gal) activity and irreversible growth arrest. However, recent data suggest that TIS cells can reactivate their proliferative potential and lead to cancer recurrence. Our previous study indicated that reactivation of proliferation by TIS cells might be related with autophagy modulation. However, exact relationship between both processes required further studies. Therefore, the aim of our study was to investigate the role of autophagy in the senescence-related chemoresistance of lung cancer cells. For this purpose, human and murine lung cancer cells were treated with two commonly used chemotherapeutics: cisplatin (CIS), which forms DNA adducts or docetaxel (DOC), a microtubule poison. Hypoxia, often overlooked in experimental settings, has been implicated as a mechanism responsible for a significant change in the response to treatment. Thus, cells were cultured under normoxic (~19% O₂) or hypoxic (1% O₂) conditions. Herein, we show that hypoxia increases resistance to CIS. Lung cancer cells cultured under hypoxic conditions escaped from CIS-induced senescence, displayed reduced SA-β-gal activity and a decreased percentage of cells in the G2/M phase of the cell cycle. In turn, hypoxia increased the proliferation of lung cancer cells and the proportion of cells proceeding to the G0/G1 phase. Further molecular analyses demonstrated that hypoxia inhibited the prosenescent p53/p21 signaling pathway and induced epithelial to mesenchymal transition in CIS-treated cancer cells. In cells treated with DOC, such effects were not observed. Of importance, pharmacological autophagy inhibitor, hydroxychloroquine (HCQ) was capable of overcoming short-term CIS-induced resistance of lung cancer cells in hypoxic conditions. Altogether, our data demonstrated that hypoxia favors cancer cell escape from CIS-induced senescence, what could be overcome by inhibition of autophagy with HCQ. Therefore, we propose that HCQ might be used to interfere with the ability of senescent cancer cells to repopulate following exposure to DNA-damaging agents. This effect, however, needs to be tested in a long-term perspective for preclinical and clinical applications.

XPC multifaceted roles beyond DNA damage repair: p53-dependent and p53-independent functions of XPC in cell fate decisions

Xeroderma pigmentosum group C protein (XPC) acts as a DNA damage recognition factor for bulky adducts and as an initiator of global genome nucleotide excision repair (GG-NER). Novel insights have shown that the role of XPC is not limited to NER, but is also implicated in DNA damage response (DDR), as well as in cell fate decisions upon stress. Moreover, XPC has a proteolytic role through its interaction with p53 and casp-2S. XPC is also able to determine cellular outcomes through its interaction with downstream proteins, such as p21, ARF, and p16. XPC interactions with effector proteins may drive cells to various fates such as apoptosis, senescence, or tumorigenesis. In this review, we explore XPC's involvement in different molecular pathways in the cell and suggest that XPC can be considered not only as a genomic caretaker and gatekeeper but also as a tumor suppressor and cellular-fate decision maker. These findings envisage that resistance to cell death, induced by DNA-damaging therapeutics, in highly prevalent P53-deficent tumors might be overcome through new therapeutic approaches that aim to activate XPC in these tumors. Moreover, this review encourages care providers to consider XPC status in cancer patients before chemotherapy in order to improve the chances of successful treatment and enhance patients' survival.

XPA Enhances Temozolomide Resistance of Glioblastoma Cells by Promoting Nucleotide Excision Repair

Glioblastoma is the most frequent, as well as aggressive kind of high-grade malignant glioma. Chemoresistance is posing a significant clinical barrier to the efficacy of temozolomide-based glioblastoma treatment. By suppressing xeroderma pigmentosum group A (XPA), a pivotal DNA damage recognition protein implicated in nucleotide excision repair (NER), we devised a novel method to enhance glioblastoma therapy and alleviate temozolomide resistance. On the basis of preliminary assessment, we found that XPA dramatically increased in glioblastoma compared with normal cells and contributed to temozolomide resistance. By constructing XPA stably knockdown cells, we illustrate that XPA protects glioma cells from temozolomide-triggered reproductive cell death, apoptosis, as well as DNA repair. Besides, XPA silencing remarkably enhances temozolomide efficacy in vivo. This study revealed a crucial function of XPA-dependent NER in the resistance of glioma cells to temozolomide.

XPC Protein Improves Lung Adenocarcinoma Prognosis by Inhibiting Lung Cancer Cell Stemness

Objective: Xeroderma Pigmentosum Complementation Group C (XPC) is a protein involving in nucleotide excision repair (NER). XPC also plays an important role in the lung cancer occurrence with the mechanism remian unclear up to date. Studies showed that the increased stemness of lung cancer cells is related to the recurrence and metastasis of lung cancer. This study aimed to study and analyze the correlation of XPC with lung cancer stem cell biomarkers expression and the overall survival (OS) of lung adenocarcinoma patients. Methods: 140 cases of clinical lung adenocarcinoma tissue samples and 48 cases of paired paracancerous tissue samples were made into tissue microarray. Immunohistochemistry (IHC) was used to detect the expression of XPC and CD133 in cancer and paracancerous tissues. Semi-quantitative analysis and statistics were performed by Pannoramic Digital Slide Scanner. The expression of XPC and CD133 in fresh tissues was verified by Western blotting assay. siXPC was used to knock down XPC in lung cancer cell lines to study the effect of XPC on the expression of lung cancer stem cell biomarkers and the ability of cell invasion. And shXPC was used to knockdown XPC in A549 and H1650 to study the effect of XPC on the expression of lung cancer stem cell biomarkers. Results: IHC and Western blotting results showed that XPC expression significantly decreased, while CD133 expression significantly increased in cancer tissues comparing to paracancerous tissues (P _XPC < 0.0001, P _CD133 = 0.0395). The high level of XPC in cancer was associated with a better prognosis (Log-rank p = 0.0577) in lung adenocarcinoma patients. Downregulation of XPC in lung cancer cells showed increased expression of cancer stem cell biomarkers and the increased cell invasion abilities. Conclusion: It is suggested that XPC can exert the ability of anti-tumor formation, tumor invasion and metastasis inhibition, and prognostic survival improvement in lung adenocarcinoma patients by regulating the stemness of lung cancer cells.

Anti-Cancer Activity of Phytochemicals Targeting Hypoxia-Inducible Factor-1 Alpha

Hypoxia-inducible factor-1 alpha (HIF-1α) is overexpressed in cancer, leading to a poor prognosis in patients. Diverse cellular factors are able to regulate HIF-1α expression in hypoxia and even in non-hypoxic conditions, affecting its progression and malignant characteristics by regulating the expression of the HIF-1α target genes that are involved in cell survival, angiogenesis, metabolism, therapeutic resistance, et cetera. Numerous studies have exhibited the anti-cancer effect of HIF-1α inhibition itself and the augmentation of anti-cancer treatment efficacy by interfering with HIF-1α-mediated signaling. The anti-cancer effect of plant-derived phytochemicals has been evaluated, and they have been found to possess significant therapeutic potentials against numerous cancer types. A better understanding of phytochemicals is indispensable for establishing advanced strategies for cancer therapy. This article reviews the anti-cancer effect of phytochemicals in connection with HIF-1α regulation.

miR-339-5p Inhibits Autophagy to Reduce the Resistance of Laryngeal Carcinoma on Cisplatin via Targeting TAK1

Laryngeal carcinoma is a malignant disease with high morbidity and mortality. Several studies have indicated that miRNA dysfunction involves in the development of laryngeal carcinoma. In this study, the connection of miR-339-5p and laryngeal carcinoma was investigated, and qRT-PCR, CCK-8, and flow cytometry assay were used to observe the function of miR-339-5p on laryngeal carcinoma. Besides, the target database, dual-luciferase reporter assay, and western blot were used to explore the regulation mechanism of miR-339-5p on the progression of laryngeal carcinoma. The results showed that miR-339-5p was significantly downregulated in cisplatin-resistant cells of laryngeal carcinoma, and miR-339-5p upregulation could weaken the resistance of laryngeal carcinoma cells on cisplatin. Moreover, miR-339-5p could directly react with 3'-UTR of TAK1, and TAK1 could reverse the effects of miR-339-5p on the progression of autophagy. In conclusion, this study suggests that miR-339-5p can inhibit the autophagy to decrease the cisplatin resistance of laryngeal carcinoma via targeting TAK1.

Pathogenesis and therapeutic strategy in platinum resistance lung cancer

Platinum compounds (cisplatin and carboplatin) represent the most active anticancer agents in clinical use both of lung cancer in mono-and combination therapies. However, platinum resistance limits its clinical application. It is necessary to understand the molecular mechanism of platinum resistance, identify predictive markers, and develop newer, more effective and less toxic agents to treat platinum resistance in lung cancer. Here, it summarizes the main molecular mechanisms associated with platinum resistance in lung cancer and the development of new approaches to tackle this clinically relevant problem. Moreover, it could lead to the development of more effective treatment for refractory lung cancer in future.

Overcoming chemotherapy resistance using pH-sensitive hollow MnO2 nanoshells that target the hypoxic tumor microenvironment of metastasized oral squamous cell carcinoma

BACKGROUND

Smart nanoscale drug delivery systems that target acidic tumor microenvironments (TME) could offer controlled release of drugs and modulate the hypoxic TME to enhance cancer therapy. The majority of previously reported MnO₂ nanostructures are nanoparticles, nanosheets, or nanocomposites incorporated with other types of nanoparticles, which may not offer the most effective method for drug loading or for the controlled release of therapeutic payloads. Previous studies have designed MnO₂ nanoshells that achieve tumor-specific and enhanced combination therapy for localized advanced cancer. However, the therapeutic effect of MnO₂ nanoshells on metastatic cancer is still uncertain.

RESULT

Here, intelligent "theranostic" platforms were synthesized based on hollow mesoporous MnO₂ (H-MnO₂) nanoshells that were loaded with chemotherapy agents docetaxel and cisplatin (TP) to form H-MnO₂-PEG/TP nanoshells, which were designed to alleviate tumor hypoxia, attenuate angiogenesis, trigger the dissolution of Mn²⁺, and synergize the efficacy of first-class anticancer chemotherapy. The obtained H-MnO₂-PEG/TP nanoshells decomposed in the acidic TME, releasing the loaded drugs (TP) and simultaneously attenuated tumor hypoxia and hypoxia-inducible factor-1α (HIF-1α) expression by inducing endogenous tumor hydrogen peroxide (H₂O₂) decomposition. In vitro experiments showed that compared with the control group, the proliferation, colony formation and migration ability of CAL27 and SCC7 cells were significantly reduced in H-MnO₂-PEG/TP group, while cell apoptosis was enhanced, and the expression of hypoxia-inducible factor-1α(HIF-1α) was down-regulated. In vivo experiments showed that tumor to normal organ uptake ratio (T/N ratio) of mice in H-MnO₂-PEG/TP group was significantly higher than that in TP group alone (without the nanoparticle), and tumor growth was partially delayed. In the H-MnO₂-PEG/TP treatment group, HE staining showed that most of the tumor cells were severely damaged, and TUNEL assay showed cell apoptosis was up-regulated. He staining of renal and liver sections showed no obvious fibrosis, necrosis or hypertrophy, indicating good biosafety. Fluorescence staining showed that HIF-1α expression was decreased, suggesting that the accumulation of MnO₂ in the tumor caused the decomposition of H₂O₂ into O₂ and alleviated the hypoxia of the tumor.

CONCLUSION

In conclusion, a remarkable in vivo and in vitro synergistic therapeutic effect is achieved through the combination of TP chemotherapy, which simultaneously triggered a series of antiangiogenic and oxidative antitumor reactions.

Scutellaria baicalensis and Their Natural Flavone Compounds as Potential Medicinal Drugs for the Treatment of Nicotine-Induced Non-Small-Cell Lung Cancer and Asthma

Flavonoids as the largest group of natural phytochemical compounds have received significant attention, as demonstrated by clinical trials, due to their chemotherapeutic and/or pharmacological effects against non-small-cell lung cancer (NSCLC) and asthma. Scutellaria baicalensis (S. baicalensis), known as one of the most popular medicinal plants and used in several countries, contains natural active flavone constituents, with the major compounds of the roots being baicalein, baicalin, wogonin, wogonoside and oroxylin A. S. baicalensis and their compounds are proven to have inhibitory effects on NSCLC cells when used at different concentrations. However, the exact mechanisms by which these compounds exert their therapeutic effects against asthma remain unexplored. Indeed, the mechanisms by which S. baicalensis and its flavone compounds exert a protective effect against nicotine-induced NSCLC and asthma are not yet fully understood. Therefore, this review explores the mechanisms involved in the therapeutic potential of flavone-rich extracts from S. baicalensis in nicotine-induced NSCLC and asthma.

Elucidating Role of Reactive Oxygen Species (ROS) in Cisplatin Chemotherapy: A Focus on Molecular Pathways and Possible Therapeutic Strategies

The failure of chemotherapy is a major challenge nowadays, and in order to ensure effective treatment of cancer patients, it is of great importance to reveal the molecular pathways and mechanisms involved in chemoresistance. Cisplatin (CP) is a platinum-containing drug with anti-tumor activity against different cancers in both pre-clinical and clinical studies. However, drug resistance has restricted its potential in the treatment of cancer patients. CP can promote levels of free radicals, particularly reactive oxygen species (ROS) to induce cell death. Due to the double-edged sword role of ROS in cancer as a pro-survival or pro-death mechanism, ROS can result in CP resistance. In the present review, association of ROS with CP sensitivity/resistance is discussed, and in particular, how molecular pathways, both upstream and downstream targets, can affect the response of cancer cells to CP chemotherapy. Furthermore, anti-tumor compounds, such as curcumin, emodin, chloroquine that regulate ROS and related molecular pathways in increasing CP sensitivity are described. Nanoparticles can provide co-delivery of CP with anti-tumor agents and by mediating photodynamic therapy, and induce ROS overgeneration to trigger CP sensitivity. Genetic tools, such as small interfering RNA (siRNA) can down-regulate molecular pathways such as HIF-1α and Nrf2 to promote ROS levels, leading to CP sensitivity. Considering the relationship between ROS and CP chemotherapy, and translating these findings to clinic can pave the way for effective treatment of cancer patients.

Long non-coding RNA MAPKAPK5-AS1/PLAGL2/HIF-1α signaling loop promotes hepatocellular carcinoma progression

Background

Long non-coding RNAs (lncRNAs) are widely involved in human cancers’ progression by regulating tumor cells’ various malignant behaviors. MAPKAPK5-AS1 has been recognized as an oncogene in colorectal cancer. However, the biological role of MAPKAPK5-AS1 in hepatocellular carcinoma (HCC) has not been explored.

Methods

Quantitative real-time PCR was performed to detect the level of MAPKAPK5-AS1 in HCC tissues and cell lines. The effects of MAPKAPK5-AS1 on tumor growth and metastasis were assessed via in vitro experiments, including MTT, colony formation, EdU, flow cytometry, transwell assays, and nude mice models. The western blotting analysis was carried out to determine epithelial-mesenchymal transition (EMT) markers and AKT signaling. The interaction between MAPKAPK5-AS1, miR-154-5p, and PLAGL2 were explored by luciferase reporter assay and RNA immunoprecipitation. The regulatory effect of HIF-1α on MAPKAPK5-AS1 was evaluated by chromatin immunoprecipitation.

Results

MAPKAPK5-AS1 expression was significantly elevated in HCC, and its overexpression associated with malignant clinical features and reduced survival. Functionally, MAPKAPK5-AS1 knockdown repressed the proliferation, mobility, and EMT of HCC cells and induced apoptosis. Ectopic expression of MAPKAPK5-AS1 contributed to HCC cell proliferation and invasion in vitro. Furthermore, MAPKAPK5-AS1 silencing suppressed, while MAPKAPK5-AS1 overexpression enhanced HCC growth and lung metastasis in vivo. Mechanistically, MAPKAPK5-AS1 upregulated PLAG1 like zinc finger 2 (PLAGL2) expression by acting as an endogenous competing RNA (ceRNA) to sponge miR-154-5p, thereby activating EGFR/AKT signaling. Importantly, rescue experiments demonstrated that the miR-154-5p/PLAGL2 axis mediated the function of MAPKAPK5-AS1 in HCC cells. Interestingly, we found that hypoxia-inducible factor 1α (HIF-1α), a transcript factor, could directly bind to the promoter to activate MAPKAPK5-AS1 transcription. MAPKAPK5-AS1 regulated HIF-1α expression through PLAGL2 to form a hypoxia-mediated MAPKAPK5-AS1/PLAGL2/HIF-1α signaling loop in HCC.

Conclusions

Our results reveal a MAPKAPK5-AS1/PLAGL2/HIF-1α signaling loop in HCC progression and suggest that MAPKAPK5-AS1 could be a potential novel therapeutic target of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01868-z.

HIF in Nephrotoxicity during Cisplatin Chemotherapy: Regulation, Function and Therapeutic Potential

Simple Summary

Cisplatin is a widely used chemotherapy drug, but its use and efficacy are limited by its nephrotoxicity. HIF has protective effects against kidney injury during cisplatin chemotherapy, but it may attenuate the anti-cancer effect of cisplatin. In this review, we describe the role and regulation of HIF in cisplatin-induced nephrotoxicity and highlight the therapeutic potential of targeting HIF in chemotherapy.

Abstract

Cisplatin is a highly effective, broad-spectrum chemotherapeutic drug, yet its clinical use and efficacy are limited by its side effects. Particularly, cancer patients receiving cisplatin chemotherapy have high incidence of kidney problems. Hypoxia-inducible factor (HIF) is the “master” transcription factor that is induced under hypoxia to trans-activate various genes for adaptation to the low oxygen condition. Numerous studies have reported that HIF activation protects against AKI and promotes kidney recovery in experimental models of cisplatin-induced acute kidney injury (AKI). In contrast, little is known about the effects of HIF on chronic kidney problems following cisplatin chemotherapy. Prolyl hydroxylase (PHD) inhibitors are potent HIF inducers that recently entered clinical use. By inducing HIF, PHD inhibitors may protect kidneys during cisplatin chemotherapy. However, HIF activation by PHD inhibitors may reduce the anti-cancer effect of cisplatin in tumors. Future studies should test PHD inhibitors in tumor-bearing animal models to verify their effects in kidneys and tumors.