Celecoxib exerts antitumor effects in HL-60 acute leukemia cells and inhibits autophagy by affecting lysosome function

Pulmonary surfactant biogenesis blockage mediated polyhexamethylene guanidine disinfectant induced pulmonary fibrosis

The widespread use of disinfectants and inhalation exposure to aerosolized forms is closely associated with adverse health effects on the respiratory system and pulmonary fibrosis, but the mechanism remains unclear. Here, we investigated the time-course pulmonary fibrosis effects of polyhexamethylene guanidine (PHMG) disinfectant inhalation exposure and elucidated its underlying mechanism. Specifically, scRNA-seq analysis revealed an initial increase in epithelial cell numbers after 4 weeks of PHMG exposure during induced pulmonary fibrosis, followed by a subsequent decrease after 8 weeks of exposure. Mechanistically, PHMG disrupted autophagic flux leading to intracellular accumulation and blocked pulmonary surfactant biogenesis in alveolar type II epithelial (AT2) cells both in vitro and in vivo. Furthermore, intervention studies using metformin confirmed that autophagy dysfunction mediated the blockage of pulmonary surfactant biogenesis in AT2 cells, playing a pivotal role in PHMG-induced pulmonary fibrosis. Our elucidation of these toxicological mechanisms provides valuable insights into the pathogenesis of pulmonary fibrosis triggered by environmental PHMG exposure, thereby offering a promising therapeutic target for mitigating and treating PHMG-associated pulmonary fibrosis.

Synergistic celecoxib and dimethyl-celecoxib combinations block cervix cancer growth through multiple mechanisms

OBJECTIVE

The synergistic inhibitory effect of celecoxib (CXB) and dimethyl-celecoxib (DMC) plus paclitaxel (PA) or cisplatin (CP) on human cervix HeLa and SiHa cells was assessed at multiple cellular levels in order to elucidate the biochemical mechanisms triggered by the synergistic drug combinations.

METHODS

The effect of CXB (5 μM)/CP (2 μM) or CXB (5 μM)/PA (15 μM) and DMC (15 μM)/CP (5 μM) or DMC (15 μM)/PA (20 μM) for 24 h was assayed on cancer cell proliferation, energy metabolism, mitophagy, ROS production, glycoprotein-P activity, DNA stability and apoptosis/necrosis.

RESULTS

Drug combinations synergistically decreased HeLa and SiHa cell proliferation (>75%) and arrested cellular cycle by decreasing S and G2/M phases as well as the Ki67 content (HeLa) by 7.5-30 times. Cell viability was preserved (>90%) and no apparent effects on non-cancer cell growth were observed. Mitochondrial and glycolytic protein contents (44-95%) and ΔΨm (45-50%) in HeLa cells and oxidative phosphorylation and glycolysis fluxes (70-90%) in HeLa and SiHa cells were severely decreased, which in turn promoted a drastic fall in the ATP supply (85-88%). High levels of mitophagy proteins in HeLa cells and active mitochondrial digestion in HeLa and SiHa cells was observed. Mitochondrial fission and microtubule proteins were also affected. Intracellular ROS content (2-2.3-fold) and ROS production was stimulated (2.3-4 times), whereas content and activity of glycoprotein-P (45-85%) were diminished. DNA fragmentation was not observed and apoptosis/necrosis was not detected suggesting that cell death could be mainly associated to mitophagy induction.

CONCLUSIONS

CXB or DMC combination with canonical chemotherapy may be a promising chemotherapy strategy against cervical cancer growth, because it can selectively block multiple cell processes including inhibition of energy pathways and in consequence ATP-dependent processes such as cell proliferation, glycoprotein-P activity, ROS production and mitophagy, with no apparent effects on non-cancer cells.

Mefenamic Acid-Upregulated Nrf2/SQSTM1 Protects Hepatocytes against Oxidative Stress-Induced Cell Damage

Mefenamic acid (MFA) is a commonly prescribed non-steroidal anti-inflammatory drug (NSAID) with anti-inflammatory and analgesic properties. MFA is known to have potent antioxidant properties and a neuroprotective effect against oxidative stress. However, its impact on the liver is unclear. This study aimed to elucidate the antioxidative effects of MFA and their underlying mechanisms. We observed that MFA treatment upregulated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Treatment with various anthranilic acid derivative-class NSAIDs, including MFA, increased the expression of sequestosome 1 (SQSTM1) in HepG2 cells. MFA disrupted the interaction between Kelch-like ECH-associated protein 1 (Keap1) and Nrf2, activating the Nrf2 signaling pathway. SQTM1 knockdown experiments revealed that the effect of MFA on the Nrf2 pathway was masked in the absence of SQSTM1. To assess the cytoprotective effect of MFA, we employed tert-Butyl hydroperoxide (tBHP) as a ROS inducer. Notably, MFA exhibited a protective effect against tBHP-induced cytotoxicity in HepG2 cells. This cytoprotective effect was abolished when SQSTM1 was knocked down, suggesting the involvement of SQSTM1 in mediating the protective effect of MFA against tBHP-induced toxicity. In conclusion, this study demonstrated that MFA exhibits cytoprotective effects by upregulating SQSTM1 and activating the Nrf2 pathway. These findings improve our understanding of the pharmacological actions of MFA and highlight its potential as a therapeutic agent for oxidative stress-related conditions.

Polyphenols: Chemoprevention and therapeutic potentials in hematological malignancies

Polyphenols are one of the largest plant-derived natural product and they play an important role in plants' defense as well as in human health and disease. A number of them are pleiotropic molecules and have been shown to regulate signaling pathways, immune response and cell growth and proliferation which all play a role in cancer development. Hematological malignancies on the other hand, are cancers of the blood. While current therapies are efficacious, they are usually expensive and with unwanted side effects. Thus, the search for newer less toxic agents. Polyphenols have been reported to possess antineoplastic properties which include cell cycle arrest, and apoptosis via multiple mechanisms. They also have immunomodulatory activities where they enhance T cell activation and suppress regulatory T cells. They carry out these actions through such pathways as PI3K/Akt/mTOR and the kynurenine. They can also reverse cancer resistance to chemotherapy agents. In this review, i look at some of the molecular mechanism of action of polyphenols and their potential roles as therapeutic agents in hematological malignancies. Here i discuss their anti-proliferative and anti-neoplastic activities especially their abilities modulate signaling pathways as well as immune response in hematological malignancies. I also looked at clinical studies done mainly in the last 10-15 years on various polyphenol combination and how they enhance synergism. I recommend that further preclinical and clinical studies be carried out to ensure safety and efficacy before polyphenol therapies be officially moved to the clinics.

Inhibiting Cytoprotective Autophagy in Cancer Therapy: An Update on Pharmacological Small-Molecule Compounds

Autophagy is a self-degradation process in which damaged proteins and organelles are engulfed into autophagosomes for digestion and eventually recycled for cellular metabolism to maintain intracellular homeostasis. Accumulating studies have reported that autophagy has the Janus role in cancer as a tumor suppressor or an oncogenic role to promote the growth of established tumors and developing drug resistance. Importantly, cytoprotective autophagy plays a prominent role in many types of human cancers, thus inhibiting autophagy, and has been regarded as a promising therapeutic strategy for cancer therapy. Here, we focus on summarizing small-molecule compounds inhibiting the autophagy process, as well as further discuss other dual-target small-molecule compounds, combination strategies, and other strategies to improve potential cancer therapy. Therefore, these findings will shed new light on exploiting more small-molecule compounds inhibiting cytoprotective autophagy as candidate drugs for fighting human cancers in the future.

Identification and validation of CALCRL-associated prognostic genes in acute myeloid leukemia

In the past few decades, several advances have been made in the field of acute myeloid leukemia (AML), especially in the development of novel drugs. However, the overall survival rate remains particularly disappointing due to a high rate of chemotherapy resistance and relapse. The calcitonin receptor-like receptor (CALCRL) is a novel promising therapeutic target of AML and has been indicated to be strongly correlated with chemotherapy resistance and relapse driven by leukemic stem cells. Nevertheless, the CALCRL downstream genes associated with the drug resistance and relapse of AML remain to be elucidated. Within this study, we used multiple gene expression datasets from the Gene Expression Omnibus (GEO) database and cBioPortal to explore the candidate CALCRL-associated genes that could potentially mediate the chemoresistance and relapse of AML. Then, we investigated the prognostic value, coexpression relationship with CALCRL, and expression characteristics of these genes using independent data from The Cancer Genome Atlas (TCGA). Eventually, three genes were screened out as CALCRL-associated prognostic genes. The expression of AGTPBP1 and LYST was negatively correlated with CALCRL, high expression of which was associated with favorable prognosis in AML. In contrast, the expression of ETS2 was positively correlated with CALCRL, high expression of which was associated with poor prognosis in AML. The results indicated that the three prognostic genes are potential CALCRL downstream genes that mediate drug resistance and relapse in AML. This study helps to further explore the role and molecular pathways of CALCRL in mediating drug resistance and relapse of AML.

NSAIDs and Cancer Resolution: New Paradigms beyond Cyclooxygenase

Acute inflammation or resolved inflammation is an adaptive host defense mechanism and is self-limiting, which returns the body to a state of homeostasis. However, unresolved, uncontrolled, or chronic inflammation may lead to various maladies, including cancer. Important evidence that links inflammation and cancer is that nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, reduce the risk and mortality from many cancers. The fact that NSAIDs inhibit the eicosanoid pathway prompted mechanistic drug developmental work focusing on cyclooxygenase (COX) and its products. The increased prostaglandin E2 levels and the overexpression of COX-2 in the colon and many other cancers provided the rationale for clinical trials with COX-2 inhibitors for cancer prevention or treatment. However, NSAIDs do not require the presence of COX-2 to prevent cancer. In this review, we highlight the effects of NSAIDs and selective COX-2 inhibitors (COXIBs) on targets beyond COX-2 that have shown to be important against many cancers. Finally, we hone in on specialized pro-resolving mediators (SPMs) that are biosynthesized locally and, in a time, -dependent manner to promote the resolution of inflammation and subsequent tissue healing. Different classes of SPMs are reviewed, highlighting aspirin's potential in triggering the production of these resolution-promoting mediators (resolvins, lipoxins, protectins, and maresins), which show promise in inhibiting cancer growth and metastasis.

Proton pump inhibitors interfere with the anti-tumor potency of RC48ADC

Antibody-drug conjugates (ADCs) are a promising modality for cancers, but the interaction between them and proton pump inhibitors (PPIs), the common adjuvant drugs for cancer treatment, has not been understood. Here, the interactions between PPIs and RC48ADC, a novel HER2-targeting ADC, were quantified in vitro. CCK-8 assay showed that RC48ADC displayed a significant inhibitory effect on the proliferation of SK-BR-3, NCI-N87 and SK-OV-3 cells with the IC₅₀ values of 4.91 ± 1.15 ng/mL, 14.54 ± 0.85 ng/mL and 11.28 ± 0.68 ng/mL respectively. PPIs alone had no significant anti-tumor effect in the dose range of 1.37-1000 ng/mL. When used together, PPIs inhibited the anti-tumor activity of RC48ADC in a dose-dependent manner. And 1000 ng/mL (~Cmax) PPIs significantly recovered RC48ADC-inhibited cell proliferation by (32.85 ± 2.81) % (p < 0.05). However, cimetidine, a non-PPIs gastric acid secretion inhibitor, had no significant inhibitory effect on RC48ADC. Furthermore, omeprazole, rather than cimetidine, significantly reduced the activity of vacuolar H⁺-ATPase and Cathepsin B compared with the control cells. These results, if confirmed in vivo, indicate that PPIs are antagonists of RC48ADC, even all ADCs, appearing to be due to inhibition of vacuolar H⁺-ATPase activity. Moreover, cimetidine combined with ADCs instead of PPIs can prevent an adverse drug interaction.

Cadherins, Selectins, and Integrins in CAM-DR in Leukemia

The interaction between leukemia cells and the bone microenvironment is known to provide drug resistance in leukemia cells. This phenomenon, called cell adhesion-mediated drug resistance (CAM-DR), has been demonstrated in many subsets of leukemia including B- and T-acute lymphoblastic leukemia (B- and T-ALL) and acute myeloid leukemia (AML). Cell adhesion molecules (CAMs) are surface molecules that allow cell-cell or cell-extracellular matrix (ECM) adhesion. CAMs not only recognize ligands for binding but also initiate the intracellular signaling pathways that are associated with cell proliferation, survival, and drug resistance upon binding to their ligands. Cadherins, selectins, and integrins are well-known cell adhesion molecules that allow binding to neighboring cells, ECM proteins, and soluble factors. The expression of cadherin, selectin, and integrin correlates with the increased drug resistance of leukemia cells. This paper will review the role of cadherins, selectins, and integrins in CAM-DR and the results of clinical trials targeting these molecules.

Diclofenac impairs autophagic flux via oxidative stress and lysosomal dysfunction: Implications for hepatotoxicity

Treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with various side effects, including cardiovascular and hepatic disorders. Studies suggest that mitochondrial damage and oxidative stress are important mediators of toxicity, yet the underlying mechanisms are poorly understood. In this study, we identified that some NSAIDs, including diclofenac, inhibit autophagic flux in hepatocytes. Further detailed studies demonstrated that diclofenac induced a reactive oxygen species (ROS)-dependent increase in lysosomal pH, attenuated cathepsin activity and blocked autophagosome-lysosome fusion. The reactivation of lysosomal function by treatment with clioquinol or transfection with the transcription factor EB restored lysosomal pH and thus autophagic flux. The production of mitochondrial ROS is critical for this process since scavenging ROS reversed lysosomal dysfunction and activated autophagic flux. The compromised lysosomal activity induced by diclofenac also inhibited the fusion with and degradation of mitochondria by mitophagy. Diclofenac-induced cell death and hepatotoxicity were effectively protected by rapamycin. Thus, we demonstrated that diclofenac induces the intracellular ROS production and lysosomal dysfunction that lead to the suppression of autophagy. Impaired autophagy fails to maintain mitochondrial integrity and aggravates the cellular ROS burden, which leads to diclofenac-induced hepatotoxicity.

The molecular mechanisms of celecoxib in tumor development

BACKGROUND

Clinical studies have shown that celecoxib can significantly inhibit the development of tumors, and basic experiments and in vitro experiments also provide a certain basis, but it is not clear how celecoxib inhibits tumor development in detail.

METHODS

A literature search of all major academic databases was conducted (PubMed, China National Knowledge Internet (CNKI), Wan-fang, China Science and Technology Journal Database (VIP), including the main research on the mechanisms of celecoxib on tumors.

RESULTS

Celecoxib can intervene in tumor development and reduce the formation of drug resistance through multiple molecular mechanisms.

CONCLUSION

Celecoxib mainly regulates the proliferation, migration, and invasion of tumor cells by inhibiting the cyclooxygenases-2/prostaglandin E2 signal axis and thereby inhibiting the phosphorylation of nuclear factor-κ-gene binding, Akt, signal transducer and activator of transcription and the expression of matrix metalloproteinase 2 and matrix metalloproteinase 9. Meanwhile, it was found that celecoxib could promote the apoptosis of tumor cells by enhancing mitochondrial oxidation, activating mitochondrial apoptosis process, promoting endoplasmic reticulum stress process, and autophagy. Celecoxib can also reduce the occurrence of drug resistance by increasing the sensitivity of cancer cells to chemotherapy drugs.

Regulation of Autophagy by Non-Steroidal Anti-Inflammatory Drugs in Cancer

Cancer is the leading cause of death, placing a substantial global health burden. The development of the most effective treatment regimen is the unmet clinical need for cancer. Inflammation plays a role in tumorigenesis and progression, and anti-inflammation may be a promising option for cancer management and prevention. Emerging studies have shown that non-steroidal anti-inflammatory drugs (NSAIDs) display anticarcinogenic and chemopreventive properties through the regulation of autophagy in certain types of cancer. In this review, we summarize the pharmacological functions and side effects of NSAIDs as chemotherapeutic agents, and focus on its mode of action on autophagy regulation, which increases our knowledge of NSAIDs and cancer-related inflammation, and contributes to a putative addition of NSAIDs in the chemoprevention and treatment of cancer.

Old drugs, new uses: Drug repurposing in hematological malignancies

Discovery and development of novel anti-cancer drugs are expensive and time consuming. Systems biology approaches have revealed that a drug being developed for a non-cancer indication can hit other targets as well, which play critical roles in cancer progression. Since drugs for non-cancer indications would have already gone through the preclinical and partial or full clinical development, repurposing such drugs for hematological malignancies would cost much less, and drastically reduce the development time, which is evident in case of thalidomide. Here, we have reviewed some of the drugs for their potential to repurpose for treating the hematological malignancies. We have also enlisted resources that can be helpful in drug repurposing.

Autophagy: novel applications of nonsteroidal anti-inflammatory drugs for primary cancer

In eukaryotic cells, autophagy is a process associated with programmed cell death. During this process, cytoplasmic proteins and organelles are engulfed by double-membrane autophagosomes, which then fuse with lysosomes to form autolysosomes. These autolysosomes then degrade their contents to recycle the cellular components. Autophagy has been implicated in a wide variety of physiological and pathological processes that are closely related to tumorigenesis. In recent years, an increasing number of studies have indicated that nonsteroidal anti-inflammatory drugs, such as celecoxib, meloxicam, sulindac, aspirin, sildenafil, rofecoxib, and sodium salicylate, have diverse effects in cancer that are mediated by the autophagy pathway. These nonsteroidal anti-inflammatory drugs can modulate tumor autophagy through the PI3K/Akt/mTOR, MAPK/ERK1/2, P53/DRAM, AMPK/mTOR, Bip/GRP78, CHOP/ GADD153, and HGF/MET signaling pathways and inhibit lysosome function, leading to p53-dependent G1 cell-cycle arrest. In this review, we summarize the research progress in autophagy induced by nonsteroidal anti-inflammatory drugs and the molecular mechanisms of autophagy in cancer cells to provide a reference for the potential benefits of nonsteroidal anti-inflammatory drugs in cancer chemotherapy.

Design of Small Molecule Autophagy Modulators: A Promising Druggable Strategy

Autophagy is a lysosome-dependent mechanism of intracellular degradation for maintaining cellular homeostasis. Dysregulation of autophagy has been verified to be closely linked to a number of human diseases. Consequently, targeting autophagy has been highlighted as a novel therapeutic strategy for clinical utility. Mounting efforts have been done in recent years to elucidate the mechanisms of autophagy regulation and to identify potential modulators of autophagy. However, most of the compounds target complex and multifaceted pathway and proteins, which may limit the evaluation of therapeutic value and in depth studies as chemical tools. Therefore, the development of specific and active autophagy modulators becomes most desirable. Here, we briefly review the regulation of autophagy and then summarize the recent development of small molecules targeting the core autophagic machinery. Finally, we put forward our viewpoints on the current problems, with the aim to provide reference for future drug discovery and potential therapeutic perspectives on novel, potent, selective autophagy modulators.

Specific role of RhoC in tumor invasion and metastasis

Rho GTPases are regulators of many cellular functions and are often dysregulated in cancer. However, the precise role of Rho proteins for tumor development is not well understood. In breast cancer, overexpression of RhoC is linked with poor prognosis. Here, we aim to compare the function of RhoC and its homolog family member RhoA in breast cancer progression. We established stable breast epithelial cell lines with inducible expression of RhoA and RhoC, respectively. Moreover, we made use of Rho-activating bacterial toxins (Cytotoxic Necrotizing Factors) to stimulate the endogenous pool of Rho GTPases in benign breast epithelial cells and simultaneously knocked down specific Rho proteins. Whereas activation of Rho GTPases was sufficient to induce an invasive phenotype in three-dimensional culture systems, overexpression of RhoA or RhoC were not. However, RhoC but not RhoA was required for invasion, whereas RhoA and RhoC equally regulated proliferation. We further identified downstream target genes of RhoC involved in invasion and identified PTGS2 (COX-2) being preferentially upregulated by RhoC. Consistently, the COX-2 inhibitor Celecoxib blocked the invasive phenotype induced by the Rho-activating toxins.

Marketed drugs used for the management of hypercholesterolemia as anticancer armament

The design of novel pharmacologic agents as well as their approval for sale in markets all over the world is a tedious and pricey process. Inevitably, oncologic patients commonly experience unwanted effects of new anticancer drugs, while the acquisition of clinical experience for these drugs is largely based on doctor–patient partnership which is not always effective. The repositioning of marketed non-antineoplastic drugs that hopefully exhibit anticancer properties into the field of oncology is a challenging option that gains ground and attracts preclinical and clinical research in an effort to override all these hindrances and minimize the risk for reduced efficacy and/or personalized toxicity. This review aims to present the anticancer properties of drugs used for the management of hypercholesterolemia. A global view of the antitumorigenicity of all marketed antihypercholesterolemic drugs is of major importance, given that atherosclerosis, which is etiologically linked to hypercholesterolemia, is a leading worldwide cause of morbidity and mortality, while hypercholesterolemia and tumorigenesis are known to be interrelated. In vitro, in vivo and clinical literature data accumulated so far outline the mechanistic basis of the antitumor function of these agents and how they could find application at the clinical setting.