Novel organometallic chloroquine derivative inhibits tumor growth

Emerging roles of lysosome homeostasis (repair, lysophagy and biogenesis) in cancer progression and therapy

In the era of personalized therapy, precise targeting of subcellular organelles holds great promise for cancer modality. Taking into consideration that lysosome represents the intersection site in numerous endosomal trafficking pathways and their modulation in cancer growth, progression, and resistance against cancer therapies, the lysosome is proposed as an attractive therapeutic target for cancer treatment. Based on the recent advances, the current review provides a comprehensive understanding of molecular mechanisms of lysosome homeostasis under 3R responses: Repair, Removal (lysophagy) and Regeneration of lysosomes. These arms of 3R responses have distinct role in lysosome homeostasis although their interdependency along with switching between the pathways still remain elusive. Recent advances underpinning the crucial role of (1) ESCRT complex dependent/independent repair of lysosome, (2) various Galectins-based sensing and ubiquitination in lysophagy and (3) TFEB/TFE proteins in lysosome regeneration/biogenesis of lysosome are outlined. Later, we also emphasised how these recent advancements may aid in development of phytochemicals and pharmacological agents for targeting lysosomes for efficient cancer therapy. Some of these lysosome targeting agents, which are now at various stages of clinical trials and patents, are also highlighted in this review.

Global Effect of COVID-19 Pandemic on Cancer Patients and its Treatment: A Systematic Review

Background

At a global level, the COVID-19 disease outbreak has had a major impact on health services and has induced disruption in routine care of health institutions, exposing cancer patients to severe risks. To provide uninterrupted tumor treatment throughout a pandemic lockdown is a major obstacle. Coronavirus disease (COVID-19) and its causative virus, SARS-CoV-2, stance considerable challenges for the management of oncology patients. COVID-19 presents particularly severe respiratory and systemic infection in aging and immunosuppressed individuals, including patients with cancer.

Objective

In the present review, we focused on emergent evidence from cancer sufferers that have been contaminated with COVID-19 and cancer patients who were at higher risk of severe COVID-19, and indicates that anticancer treatment may either rise COVID-19 susceptibility or have a duple therapeutic impact on cancer as well as COVID-19; moreover, how SARS-CoV-2 infection impacts cancer cells. Also, to assess the global effect of the COVID-19 disease outbreak on cancer and its treatment.

Methods

A literature survey was conducted using PubMed, Web of Science (WOS), Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and VIral Protein domain DataBase (VIP DB) between Dec 1, 2019 and Sep 23, 2021, for studies on anticancer treatments in patients with COVID-19. The characteristics of the patients, treatment types, mortality, and other additional outcomes were extracted and pooled for synthesis.

Results

This disease has a huge effect on sufferers who have cancer(s). Sufferers of COVID-19 have a greater percentage of tumor diagnoses than the rest of the population. Likewise, cancer and highest proportion is lung cancer sufferers are more susceptible to COVID-19 constriction than the rest of the population.

Conclusion

Sufferers who have both COVID-19 and tumor have a considerably elevated death risk than single COVID-19 positive patients overall. During the COVID-19 pandemic, there was a reduction in the screening of cancer and detection, and also deferral of routine therapies, which may contribute to an increase in cancer mortality there in future.

Autophagy-inhibiting biomimetic nanodrugs enhance photothermal therapy and boost antitumor immunity

The instinctive protective stress responses of tumor cells hamper the low-temperature photothermal therapy (LTPTT), resulting in tumor recurrence and metastasis. The rapid blood clearance and low-efficiency tumor enrichment of nanomedicines...

Unraveling GLUT-mediated transcytosis pathway of glycosylated nanodisks

Glucose transporter (GLUT)-mediated transcytosis has been validated as an efficient method to cross the blood-brain barrier and enhance brain transport of nanomedicines. However, the transcytosis process remains elusive. Glycopeptide-modified nanodisks (Gly-A7R-NDs), which demonstrated high capacity of brain targeting via GLUT-mediated transcytosis in our previous reports, were utilized to better understand the whole transcytosis process. Gly-A7R-NDs internalized brain capillary endothelial cells mainly via GLUT-mediated/clathrin dependent endocytosis and macropinocytosis. The intracellular Gly-A7R-NDs remained intact, and the main excretion route of Gly-A7R-NDs was lysosomal exocytosis. Glycosylation of nanomedicine was crucial in GLUT-mediated transcytosis, while morphology did not affect the efficiency. This study highlights the pivotal roles of lysosomal exocytosis in the process of GLUT-mediated transcytosis, providing a new impetus to development of brain targeting drug delivery by accelerating lysosomal exocytosis.

Proteomics reveals a therapeutic vulnerability via the combined blockade of APE1 and autophagy in lung cancer A549 cells

BACKGROUND

Drug resistance is a major cause of therapeutic failure that is often associated with elevated autophagy and apurinic/apyrimidinic endonuclease 1 (APE1) expression. Herein, we investigated the role of APE1 and autophagy in A549 cells treated with cisplatin.

METHODS

SILAC proteomics was applied to obtain a panoramic view of cisplatin treatment in KRAS^G12S-mutant A549 cells. Quantity analysis of cellular apoptosis and autophagy was based on flow cytometry. Western blotting was used to examine the expression levels of apoptosis- and autophagy-related proteins, as well as those of APE1. Knockdown of APE1 was achieved by RNA interference. Immunoprecipitation was further employed to reveal the molecular interaction of APE1, p53, and LC3 when A549 cells were exposed to cisplatin.

RESULTS

SILAC proteomics revealed that 72 canonical pathways, including base excision repair (BER) and autophagy signalling pathways, were regulated after cisplatin treatment in A549 cells. Cisplatin markedly induced autophagy and apoptosis in A549 cells, accompanied by remarkable APE1 increase. Suppression of autophagy enhanced the inhibition effect of cisplatin on cell growth, proliferation, and colony formation; however, APE1 inhibition enhanced the expression of LC3-I/II, suggesting that APE1 and autophagy are compensatory for cell survival to evade the anticancer action of cisplatin. Immunoprecipitation results revealed the triple complex of APE1-p53-LC3 in response to cisplatin plus CQ in A549 cells. Dual inhibition of APE1 and autophagy significantly enhanced cisplatin-induced apoptosis, which eventually overcame drug resistance in cisplatin-resistant A549 cells.

CONCLUSIONS

Dual inhibition of APE1 and autophagy greatly enhances apoptosis in parental KRAS^G12S-mutant A549 cells and cisplatin-resistant A549 cells via regulation of APE1-p53-LC3 complex assembly, providing therapeutic vulnerability to overcome cisplatin resistance in the context of KRAS^G12S-mutant lung cancer.

Facts and Myths: Efficacies of Repurposing Chloroquine and Hydroxychloroquine for the Treatment of COVID-19

The emergence of coronavirus disease 2019 (COVID-19) is caused by the 2019 novel coronavirus (2019-nCoV). The 2019-nCoV first broke out in Wuhan and subsequently spread worldwide owing to its extreme transmission efficiency. The fact that the COVID-19 cases and mortalities are reported globally and the WHO has declared this outbreak as the pandemic, the international health authorities have focused on rapid diagnosis and isolation of patients as well as search for therapies able to counter the disease severity. Due to the lack of known specific, effective and proven therapies as well as the situation of public-health emergency, drug repurposing appears to be the best armour to find a therapeutic solution against 2019-nCoV infection. Repurposing anti-malarial drugs and chloroquine (CQ)/ hydroxychloroquine (HCQ) have shown efficacy to inhibit most coronaviruses, including SARS-CoV-1 coronavirus. These CQ analogues have shown potential efficacy to inhibit 2019-nCoV in vitro that leads to focus several future clinical trials. This review discusses the possible effective roles and mechanisms of CQ analogues for interfering with the 2019-nCoV replication cycle and infection.

In Situ Autophagy Disruption Generator for Cancer Theranostics

Cancer remains a serious clinical disease awaiting new effective treatment strategies. Autophagy modulation has emerged as a novel and promising pharmacologic target critical to future drug development and anti-cancer therapy applications. Herein, we constructed an in situ autophagy disruption generator to break the balance of autophagy flow for tumor-targeting therapy. Hollow mesoporous manganese trioxide (Mn₂O₃) nanoparticles (NPs) were synthesized and conjugated with hyaluronic acid (HA) to form tumor-targeting drug carriers. Then, traditional autophagy inhibitor hydroxychloroquine (HCQ) was loaded into the hollow core of HA-Mn₂O₃, to form a multifunctional theranostics platform (HA-Mn₂O₃/HCQ). This nanoplatform displayed specific localization and retention in lysosomes after entering tumor cells. The synchronous release of HCQ and manganese ion (Mn²⁺) induced lysosomal alkalization and osmotic pressure elevation. Significantly greater lysosomal deacidification and autophagy blockade effect emerged after treatment by this nanoplatform, with in vitro tumor inhibition rate of 92.2%. Imaging experiment proved that it could selectively deliver HCQ to tumor sites and further degrade to realize simultaneous release of Mn²⁺ and HCQ. Micromorphological and immunofluorescence analysis demonstrated that in situ high concentrations of these two substances would achieve effective autophagy blockade. Pharmacodynamics test showed that this nanogenerator displayed the best therapeutic efficacy with 5.08-fold tumor inhibition ratio compared with the HCQ group. Moreover, the generated Mn²⁺ can be used as T1 contrast agent for visualizing tumor lesions and monitoring therapeutic effects. Overall, the as-made multifunctional drug-delivery system might provide a promising platform for cancer theranostics upon in situ autophagy disruption.

Is a combination of progesterone and chloroquine more effective than either alone in the treatment of cerebral ischemic injury?

BACKGROUND

In this proof-of-concept paper, we investigated whether combination treatment with progesterone (P4) and chloroquine (CQ) would reduce ischemic injury more effectively than either agent alone in a transient middle cerebral artery occlusion (tMCAO) model in male rats.

METHODS

P4 (8 mg/kg) and CQ (25 mg/kg) were given alone or in combination beginning at different times during surgery and for 3 days post-occlusion. Locomotor activity and grip strength were evaluated as measures of impairment and recovery. Infarct size was assessed by TTC staining. Markers of autophagy (LC3 and SQSTM1/p62) and apoptosis (Bcl-2 and Bax) were evaluated with western blotting.

RESULTS

At the doses we employed, the combination was not more effective than either drug given separately on measures of grip strength or locomotor activity. However, combination therapy substantially reduced infarct size, and significantly increased Bcl-2 protein levels and suppressed Bax expression. Progesterone decreased the expression of LC3-II 24 h and SQSTM1/p62 after ischemia.

CONCLUSIONS

Our findings suggest that combination therapy with P4 and CQ is not detrimental and has a small-to-moderate additive neuroprotective effect on ischemic injury in rats without substantively affecting behavioral outcomes. CQ and P4 may help to regulate the expression of both autophagy-related and apoptosis-related proteins.

Autophagy in endothelial cells and tumor angiogenesis

In mammalian cells, autophagy is the major pathway for the degradation and recycling of obsolete and potentially noxious cytoplasmic materials, including proteins, lipids, and whole organelles, through the lysosomes. Autophagy maintains cellular and tissue homeostasis and provides a mechanism to adapt to extracellular cues and metabolic stressors. Emerging evidence unravels a critical function of autophagy in endothelial cells (ECs), the major components of the blood vasculature, which delivers nutrients and oxygen to the parenchymal tissue. EC-intrinsic autophagy modulates the response of ECs to various metabolic stressors and has a fundamental role in redox homeostasis and EC plasticity. In recent years moreover, genetic evidence suggests that autophagy regulates pathological angiogenesis, a hallmark of solid tumors. In the hypoxic, nutrient-deprived, and pro-angiogenic tumor microenvironment, heightened autophagy in the blood vessels is emerging as a critical mechanism enabling ECs to dynamically accommodate their higher bioenergetics demands to the extracellular environment and connect with other components of the tumor stroma through paracrine signaling. In this review, we provide an overview of the major cellular mechanisms regulated by autophagy in ECs and discuss their potential role in tumor angiogenesis, tumor growth, and response to anticancer therapy.

Vascular homeostasis relies on the proper behavior of endothelial cells (ECs). Emerging evidence indicate a critical role of autophagy, a vesicular process for lysosomal degradation of cytoplasmic content, in EC biology. While EC-intrinsic autophagy promotes EC function and quiescent state through redox homeostasis and possibly metabolic control, a role for EC-associated autophagy in cancer seems more complex.

Toward fully exploiting the therapeutic potential of marketed pharmaceuticals: the use of octreotide and chloroquine in oncology

Pleiotropy in biological systems and their targeting allows many pharmaceuticals to be used for multiple therapeutic purposes. Fully exploiting the therapeutic properties of drugs that are already marketed would be highly advantageous. This is especially the case in the field of oncology, where the ineffectiveness of typical anticancer agents is a common issue, while the development of novel anticancer agents is a costly and particularly time-consuming process. Octreotide and chloroquine are two pharmaceuticals that exhibit profound antitumorigenic activities. However, the current therapeutic use of octreotide is restricted primarily to the management of acromegaly and neuroendocrine tumors, both of which are rare medical conditions. Similarly, chloroquine is used mainly for the treatment of malaria, which is designated as a rare disease in Western countries. This limited exploitation contradicts the experimental findings of numerous studies outlining the possible expansion of the use of octreotide to include the treatment of common human malignancies and the repositioning of chloroquine in oncology. Herein, we review the current knowledge on the antitumor function of these two agents stemming from preclinical or clinical experimentation. In addition, we present in silico evidence on octreotide potentially binding to multiple Wnt-pathway components. This will hopefully aid in the design of new efficacious anticancer therapeutic regimens with minimal toxicity, which represents an enormous unmet demand in oncology.

Chloroquine Urea Derivatives: Synthesis and Antitumor Activity in Vitro

In the current paper, we describe the design, synthesis and antiproliferative screening of novel chloroquine derivatives with a quinoline core linked to a hydroxy or halogen amine through a flexible aminobutyl chain and urea spacer. Synthetic pathway leading to chloroquine urea derivatives 4-10 includes two crucial steps: i) synthesis of chloroquine benzotriazolide 3 and ii) formation of urea derivatives through the reaction of compound 3 with the corresponding amine. Testing of antiproliferative activity against four human cancer cell lines revealed that chloroquine urea derivatives 9 and 10 with aromatic moieties show activity at micromolar concentrations. Therefore, these molecules represent interesting lead compounds that might provide an insight into the design of new anticancer agents.