Psoralen with ultraviolet A-induced apoptosis of cutaneous lymphoma cell lines is augmented by type I interferons via the JAK1-STAT1 pathway

The complex development of psoralen-interstrand crosslink resistance in Escherichia coli requires AcrR inactivation, retention of a marbox sequence, and one of three MarA, SoxS, or Rob global regulators

Crosslinking agents, such as psoralen and UVA radiation, can be effectively used as antimicrobials and for treating several dysplastic conditions in humans, including some cancers. Yet, both cancer cells and bacteria can become resistant to these compounds, making it important to understand how resistance develops. Recently, several mutants were isolated that developed high levels of resistance to these compounds through upregulation of components of the AcrAB-TolC efflux pump. Here, we characterized these mutants and found that resistance specifically requires inactivating mutations of the acrR transcriptional repressor which also retain the marbox sequence found within this coding region. In addition, the presence of any one of three global regulators, MarA, SoxS, or Rob, is necessary and sufficient to bind to the marbox sequence and activate resistance. Notably, although psoralen is a substrate for the efflux pump, these regulators are not naturally responsive to this stress as neither psoralen, UVA, nor crosslink induction upregulates acrAB expression in the absence of mutation.

The complex development of psoralen-interstrand crosslink resistance in Escherichia coli requires AcrR inactivation, retention of a marbox sequence, and one of three MarA, SoxS, or Rob global regulators

Crosslinking agents, such as psoralen and UVA radiation, can be effectively used as antimicrobials and for treating several dysplastic conditions in humans, including some cancers. Yet, both cancer cells and bacteria can become resistant to these compounds, making it important to understand how resistance develops. Recently, several mutants were isolated that developed high-levels of resistance to these compounds through upregulation of components of the AcrAB-TolC-efflux pump. Here, we characterized these mutants and found that resistance specifically requires inactivating mutations of the acrR transcriptional repressor which also retain the marbox sequence found within this coding region. In addition, the presence of any one of three global regulators, MarA, SoxS, or Rob, is necessary and sufficient to bind to the marbox sequence and activate resistance. Notably, although psoralen is a substrate for the efflux pump, these regulators are not naturally responsive to this stress as neither psoralen, UVA, nor crosslink induction upregulates acrAB expression in the absence of mutation.

Anti-tumor effect and hepatotoxicity mechanisms of psoralen

In recent years, natural products have gradually become an important source for new drug development due to their advantages of multi-components, multi-targets, and good safety profiles. Psoralen, a furanocoumarin compound extracted from the traditional Chinese medicine psoralea corylifolia, is widely distributed among various plants. It has attracted widespread attention in the research community due to its pharmacological activities, including antitumor, anti-inflammatory, antioxidant, and neuroprotective effects. Studies have shown that psoralen has broad spectrum anti-tumor activities, offering resistance to malignant tumors such as breast cancer, liver cancer, glioma, and osteosarcoma, making it a natural, novel potential antitumor drug. Psoralen mainly exerts its antitumor effects by inhibiting tumor cell proliferation, inducing apoptosis, inhibiting tumor cell migration, and reversing multidrug resistance, presenting a wide application prospect in the field of antitumor therapy. With the deepening research on psoralea corylifolia, its safety has attracted attention, and reports on the hepatotoxicity of psoralen have gradually increased. Therefore, this article reviews recent studies on the mechanism of antitumor effects of psoralen and focuses on the molecular mechanisms of its hepatotoxicity, providing insights for the clinical development of low-toxicity, high-efficiency antitumor drugs and the safety of clinical medication.

Mutations in AcrR and RNA Polymerase Confer High-Level Resistance to Psoralen-UVA Irradiation

DNA interstrand cross-links, such as those formed by psoralen-UVA irradiation, are highly toxic lesions in both humans and bacteria, with a single lesion being lethal in Escherichia coli. Despite the lack of effective repair, human cancers and bacteria can develop resistance to cross-linking treatments, although the mechanisms of resistance remain poorly defined. Here, we subjected E. coli to repeated psoralen-UVA exposure to isolate three independently derived strains that were >10,000-fold more resistant to this treatment than the parental strain. Analysis of these strains identified gain-of-function mutations in the transcriptional regulator AcrR and the alpha subunit of RNA polymerase that together could account for the resistance of these strains. Resistance conferred by the AcrR mutation is mediated at least in part through the regulation of the AcrAB-TolC efflux pump. Resistance via mutations in the alpha subunit of RNA polymerase occurs through a still-uncharacterized mechanism that has an additive effect with mutations in AcrR. Both acrR and rpoA mutations reduced cross-link formation in vivo. We discuss potential mechanisms in relation to the ability to repair and survive interstrand DNA cross-links. IMPORTANCE Psoralen DNA interstrand cross-links are highly toxic lesions with antimicrobial and anticancer properties. Despite the lack of effective mechanisms for repair, cells can become resistant to cross-linking agents through mechanisms that remain poorly defined. We derived resistant mutants and identified that two gain-of-function mutations in AcrR and the alpha subunit of RNA polymerase confer high levels of resistance to E. coli treated with psoralen-UVA. Resistance conferred by AcrR mutations occurs through regulation of the AcrAB-TolC efflux pump, has an additive effect with RNA polymerase mutations, acts by reducing the formation of cross-links in vivo, and reveals a novel mechanism by which these environmentally and clinically important agents are processed by the cell.

Shining a Light on Prostate Cancer: Photodynamic Therapy and Combination Approaches

Prostate cancer is a major health concern worldwide, and current treatments, such as surgery, radiation therapy, and chemotherapy, are associated with significant side effects and limitations. Photodynamic therapy (PDT) is a promising alternative that has the potential to provide a minimally invasive and highly targeted approach to treating prostate cancer. PDT involves the use of photosensitizers (PSs) that are activated by light to produce reactive oxygen species (ROS), which can induce tumor cell death. There are two main types of PSs: synthetic and natural. Synthetic PSs are classified into four generations based on their structural and photophysical properties, while natural PSs are derived from plant and bacterial sources. Combining PDT with other therapies, such as photothermal therapy (PTT), photoimmunotherapy (PIT), and chemotherapy (CT), is also being explored as a way to improve its efficacy. This review provides an overview of conventional treatments for prostate cancer, the underlying principles of PDT, and the different types of PSs used in PDT as well as ongoing clinical studies. It also discusses the various forms of combination therapy being explored in the context of PDT for prostate cancer, as well as the challenges and opportunities associated with this approach. Overall, PDT has the potential to provide a more effective and less invasive treatment option for prostate cancer, and ongoing research is aimed at improving its selectivity and efficacy in clinical settings.

An Overview of Potential Natural Photosensitizers in Cancer Photodynamic Therapy

Cancer is one of the main causes of death worldwide. There are several different types of cancer recognized thus far, which can be treated by different approaches including surgery, radiotherapy, chemotherapy or a combination thereof. However, these approaches have certain drawbacks and limitations. Photodynamic therapy (PDT) is regarded as an alternative noninvasive approach for cancer treatment based on the generation of toxic oxygen (known as reactive oxygen species (ROS)) at the treatment site. PDT requires photoactivation by a photosensitizer (PS) at a specific wavelength (λ) of light in the vicinity of molecular oxygen (singlet oxygen). The cell death mechanisms adopted in PDT upon PS photoactivation are necrosis, apoptosis and stimulation of the immune system. Over the past few decades, the use of natural compounds as a photoactive agent for the selective eradication of neoplastic lesions has attracted researchers' attention. Many reviews have focused on the PS cell death mode of action and photonanomedicine approaches for PDT, while limited attention has been paid to the photoactivation of phytocompounds. Photoactivation is ever-present in nature and also found in natural plant compounds. The availability of various laser light setups can play a vital role in the discovery of photoactive phytocompounds that can be used as a natural PS. Exploring phytocompounds for their photoactive properties could reveal novel natural compounds that can be used as a PS in future pharmaceutical research. In this review, we highlight the current research regarding several photoactive phytocompound classes (furanocoumarins, alkaloids, poly-acetylenes and thiophenes, curcumins, flavonoids, anthraquinones, and natural extracts) and their photoactive potential to encourage researchers to focus on studies of natural agents and their use as a potent PS to enhance the efficiency of PDT.

Safety and Danger Considerations of Novel Treatments for Atopic Dermatitis in Context of Primary Cutaneous Lymphomas

The impact of new and emerging therapies on the microenvironment of primary cutaneous lymphomas (PCLs) has been recently raised in the literature. Concomitantly, novel treatments are already used or registered (dupilumab, upadacitinib) and others seem to be added to the armamentarium against atopic dermatitis. Our aim was to review the literature on interleukins 4, 13, 22, and 31, and JAK/STAT pathways in PCLs to elucidate the safety of using biologics (dupilumab, tralokinumab, fezakinumab, nemolizumab) and small molecule inhibitors (upadacitinib, baricitinib, abrocitinib, ruxolitinib, tofacitinib) in the treatment of atopic dermatitis. We summarized the current state of knowledge on this topic based on the search of the PubMed database and related references published before 21 October 2021. Our analysis suggests that some of the mentioned agents (dupilumab, ruxolitinib) and others may have a direct impact on the progression of cutaneous lymphomas. This issue requires further study and meticulous monitoring of patients receiving these drugs to ensure their safety, especially in light of the FDA warning on tofacitinib. In conclusion, in the case of the rapid progression of atopic dermatitis/eczema, especially in patients older than 40 years old, there is a necessity to perform a biopsy followed by a very careful pathological examination.

CXCR4 allows T cell acute lymphoblastic leukemia to escape from JAK1/2 and BCL2 inhibition through CNS infiltration

Targeting the JAK/STAT and BCL2 pathways in patients with relapsed/refractory T cell acute lymphoblastic leukemia (T-ALL) may provide an alternative approach to achieve clinical remissions. Ruxolitinib and venetoclax show a dose-dependent effect on T-ALL individually, but combination treatment reduces survival and proliferation of T-ALL in vitro. Using a xenograft model, the combination treatment fails to improve survival, with death from hind limb paralysis. Despite on-target inhibition by the drugs, histopathology demonstrates increased leukemic infiltration into the central nervous system (CNS) as compared to liver or bone marrow. Liquid chromatography-tandem mass spectroscopy shows that ruxolitinib and venetoclax insufficiently cross into the CNS. The addition of the CXCR4 inhibitor plerixafor with ruxolitinib and venetoclax reduces clinical scores and enhances survival. While combination therapy with ruxolitinib and venetoclax shows promise for treating T-ALL, additional inhibition of the CXCR4-CXCL12 axis may be needed to maximize the possibility of complete remission.

The role of P53 up-regulated modulator of apoptosis (PUMA) in ovarian development, cardiovascular and neurodegenerative diseases

P53 up-regulated modulator of apoptosis (PUMA), a pro-apoptotic BCL-2 homology 3 (BH3)-only member of the BCL-2 family, is a direct transcriptional target of P53 that elicits mitochondrial apoptosis under treatment with radiation and chemotherapy. It also induces excessive apoptosis in cardiovascular and/or neurodegenerative diseases. PUMA has been found to play a critical role in ovarian apoptosis. In the present paper, we review the progress of the study in PUMA over the past two decades in terms of its inducement and/or amplification of programmed cell death and describe recent updates to the understanding of both P53-dependent and P53-independent PUMA-mediated apoptotic pathways that are implicated in physiology and pathology, including the development of the ovary and cardiovascular and neurodegenerative diseases. We propose that PUMA may be a key regulator during ovary development, provide a model for PUMA-mediated apoptotic pathways, including intrinsic and extrinsic apoptotic pathways.

Systemic treatments for eczema: a network meta-analysis

BACKGROUND

Eczema is a common and chronic, relapsing, inflammatory skin disorder. It seriously impacts quality of life and economic outcomes, especially for those with moderate to severe eczema. Various treatments allow sustained control of the disease; however, their relative benefit remains unclear due to the limited number of trials directly comparing treatments.

OBJECTIVES

To assess the comparative efficacy and safety of different types of systemic immunosuppressive treatments for moderate to severe eczema using NMA and to generate rankings of available systemic immunosuppressive treatments for eczema according to their efficacy and safety.

SEARCH METHODS

We searched the following databases up to August 2019: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, and Embase.

SELECTION CRITERIA

All randomised controlled trials (RCTs) of systemic immunosuppressive agents for moderate to severe atopic eczema when compared against placebo or any other eligible eczema treatment.

DATA COLLECTION AND ANALYSIS

We synthesised data using pair-wise analysis and NMA to compare treatments and rank them according to their effectiveness. Effectiveness was assessed primarily by determining the proportion of participants who achieved at least 75% improvement in the Eczema Area and Severity Index (EASI75) and improvement in the Patient-Oriented Eczema Measure (POEM). Safety was evaluated primarily by considering the proportion of participants with serious adverse events (SAEs) and infection. We deemed short-term follow-up as ≤ 16 weeks and long-term follow-up as > 16 weeks. We assessed the certainty of the body of evidence from the NMA for these primary outcomes using six domains of CiNEMA grading.

MAIN RESULTS

We included a total of 74 studies, with 8177 randomised participants. Approximately 55% of participants were male, with average age of 32 years (range 2 to 84 years), although age and gender were unreported for 419 and 902 participants, respectively. Most of the included trials were placebo controlled (65%), 34% were head-to-head studies (15% assessed the effects of different doses of the same drug), and 1% were multi-armed studies with both an active comparator and a placebo. All trials included participants with moderate to severe eczema, but 62% of studies did not separate data by severity; 38% of studies assessed only severe eczema. The total duration of included trials ranged from 2 weeks to 60 months, whereas treatment duration varied from a single dose (CIM331, KPL-716) to 60 months (methotrexate (MTX)). Seventy studies were available for quantitative synthesis; this review assessed 29 immunosuppressive agents from three classes of interventions. These included (1) conventional treatments, with ciclosporin assessed most commonly; (2) small molecule treatments, including phosphodiesterase (PDE)-4 inhibitors, tyrosine kinase inhibitors, and Janus kinase (JAK) inhibitors; and (3) biological treatments, including anti-CD31 receptors, anti-interleukin (IL)-22, anti-IL-31, anti-IL-13, anti-IL-12/23p40, anti-OX40, anti-TSLP, anti-CRTH2, and anti-immunoglobulin E (IgE) monoclonal antibodies, but most commonly dupilumab. Most trials (73) assessed outcomes at a short-term duration ranging from 2 to 16 weeks, whereas 33 trials assessed long-term outcomes, with duration ranging from 5 to 60 months. All participants were from a hospital setting. Fifty-two studies declared a source of funding, and of these, pharmaceutical companies funded 88%. We rated 37 studies as high risk; 21, unclear risk, and 16, low risk of bias, with studies most commonly at high risk of attrition bias. Network meta-analysis suggests that dupilumab ranks first for effectiveness when compared with other biological treatments. Dupilumab is more effective than placebo in achieving EASI75 (risk ratio (RR) 3.04, 95% confidence interval (CI) 2.51 to 3.69) and improvement in POEM score (mean difference 7.30, 95% CI 6.61 to 8.00) at short-term follow-up (high-certainty evidence). Very low-certainty evidence means we are uncertain of the effects of dupilumab when compared with placebo, in terms of the proportion of participants who achieve EASI75 (RR 2.59, 95% CI 1.87 to 3.60) at longer-term follow-up. Low-certainty evidence indicates that tralokinumab may be more effective than placebo in achieving short-term EASI75 (RR 2.54, 95% CI 1.21 to 5.34), but there was no evidence for tralokinumab to allow us to assess short-term follow-up of POEM or long-term follow-up of EASI75. We are uncertain of the effect of ustekinumab compared with placebo in achieving EASI75 (long-term follow-up: RR 1.17, 95% CI 0.40 to 3.45; short-term follow-up: RR 0.91, 95% CI 0.28 to 2.97; both very low certainty). We found no evidence on ustekinumab for the POEM outcome. We are uncertain whether other immunosuppressive agents that targeted our key outcomes influence the achievement of short-term EASI75 compared with placebo due to low- or very low-certainty evidence. Dupilumab and ustekinumab were the only immunosuppressive agents evaluated for longer-term EASI75. Dupilumab was the only agent evaluated for improvement in POEM during short-term follow-up. Low- to moderate-certainty evidence indicates a lower proportion of participants with SAEs after treatment with QAW039 and dupilumab compared to placebo during short-term follow-up, but low- to very low-certainty evidence suggests no difference in SAEs during short-term follow-up of other immunosuppressive agents compared to placebo. Evidence for effects of immunosuppressive agents on risk of any infection during short-term follow-up and SAEs during long-term follow-up compared with placebo was of low or very low certainty but did not indicate a difference. We did not identify differences in other adverse events (AEs), but dupilumab is associated with specific AEs, including eye inflammation and eosinophilia.

AUTHORS' CONCLUSIONS

Our findings indicate that dupilumab is the most effective biological treatment for eczema. Compared to placebo, dupilumab reduces eczema signs and symptoms in the short term for people with moderate to severe atopic eczema. Short-term safety outcomes from clinical trials did not reveal new safety concerns with dupilumab. Overall, evidence for the efficacy of most other immunosuppressive treatments for moderate to severe atopic eczema is of low or very low certainty. Given the lack of data comparing conventional with newer biological treatments for the primary outcomes, there remains high uncertainty for ranking the efficacy and safety of conventional treatments such as ciclosporin and biological treatments such as dupilumab. Most studies were placebo-controlled and assessed only short-term efficacy of immunosuppressive agents. Further adequately powered head-to-head RCTs should evaluate comparative long-term efficacy and safety of available treatments for moderate to severe eczema.

Immunotherapy for Cutaneous T-Cell Lymphoma: Current Landscape and Future Developments

Mycosis fungoides (MF) and Sézary syndrome (SS) are chronic, progressive primary cutaneous T-cell lymphomas (CTCLs) for which there are no curative treatments. Skin-directed therapies, such as phototherapy, radiation therapy, or topical nitrogen mustard, provide only short-term remissions. Numerous attempts with different chemotherapeutic regimes failed to achieve meaningful clinical responses. Immunotherapy seems to be a promising avenue to achieve long-term disease control in CTCL. There is compelling evidence indicating that MF and SS are immunogenic lymphomas, which can be recognized by the patient's immune system. However, CTCL uses different strategies to impair host's immunity, eg, via repolarizing the T-cell differentiation from type I to type II, recruiting immunosuppressive regulatory T-cells, and limiting the repertoire of lymphocytes in the circulation. Many currently used therapies, such as interferon-α, imiquimod, extracorporeal phototherapy, and allogeneic bone marrow transplant, seem to exert their therapeutic effect via activation of the antitumor cytotoxic response and reconstitution of the host's immune system. It is likely that novel immunotherapies such as immune checkpoint inhibitors, cancer vaccines, and chimeric antigen receptor-T cells will help to manage CTCL more efficiently. We also discuss how current genomic techniques, such as estimating the mutational load by whole genome sequencing and neoantigen calling, are likely to provide clinically useful information facilitating personalized immunotherapy of CTCL.

Transcriptome Analysis of Immune Response of mIgM+ B Lymphocytes in Japanese Flounder (Paralichthys olivaceus) to Lactococcus lactis in vitro Revealed That IFN I-3 Could Enhance Their Phagocytosis

B cells have recently been proven to have phagocytic activities, but few studies have explored the relevant regulation mechanisms. In this study, we showed that the Japanese flounder (Paralichthys olivaceus) membrane-bound (m)IgM⁺ B lymphocyte population could phagocytose inactivated Lactococcus lactis with a mean phagocytic rate of 25%. High-purity mIgM⁺ B lymphocytes were subsequently sorted to investigate the cellular response to L. lactis stimulation in vitro. Transcriptome analysis identified 1,375 differentially expressed genes (DEGs) after L. lactis stimulation, including 975 upregulated and 400 downregulated genes. Many of these DEGs were enriched in multiple pathways associated with phagocytosis such as focal adhesion, the phagosome, and actin cytoskeleton regulation. Moreover, many genes involved in phagolysosomal function and antigen presentation were also upregulated after stimulation, indicating that mIgM⁺ B lymphocytes may degrade the internalized bacteria and present processed antigenic peptides to other immune cells. Interestingly, the type I interferon 3 (IFN I-3) gene was upregulated after L. lactis stimulation, and further analysis showed that the recombinant (r)IFN I-3 significantly enhanced phagocytosis of L. lactis and Edwardsiella tarda by mIgM⁺ B lymphocytes. In addition, significantly higher intracellular reactive oxygen species (ROS) levels were detected in mIgM⁺ B lymphocytes following rIFN I-3 treatment. We also found that IFN I-3 significantly upregulated Stat1 expression in mIgM⁺ B lymphocytes, and the enhancing effect of IFN I-3 on mIgM⁺ B lymphocyte-mediated phagocytosis was suppressed by fludarabine treatment. Collectively, these results demonstrate that mIgM⁺ B cell-mediated phagocytosis in the Japanese flounder is effectively triggered by bacterial stimulation, and further enhanced by IFN I-3, which itself may be regulated by Stat1.

Coralyne, a protoberberine alkaloid, causes robust photosenstization of cancer cells through ATR-p38 MAPK-BAX and JAK2-STAT1-BAX pathways

Photodynamic therapy (PDT) provides an effective cancer treatment option but it requires sufficient cellular oxygen concentration to exert its photosensitizing effects. Due to hypoxic nature of most tumors, widespread clinical application of PDT is restricted and warrants development of photosensitizers which can kill cancer cells in ROS independent manner. Previously, we reported significant enhancement of the anti-cancer property of coralyne in presence of ultraviolet-A (UVA) light exposure against several human carcinoma cell lines. This study aimed at unravelling molecular cascades of events in CUVA treatment (coralyne and UVA light)-mediated photosensitization of human skin cancer. The CUVA-treatment caused robust apoptosis of A431 cancer cells, primarily through mitochondrial and lysosomal dysfunctions. Silencing of BAX conferred a significant protection against CUVA-induced apoptosis. Both lysosomal proteases and caspase-8 activation contributed to BID cleavage. Further, our results revealed that a dual signaling axis e.g., ATR-p38 MAPK and JAK2-STAT1 pathways functioned upstream of BAX activation in apoptosis response. Moreover, transient silencing of ATR and pharmacological inhibition of p38-MAPK or JAK2 significantly abolished the effect of CUVA treatment induced BAX expression and cell death, linking the extrinsic and intrinsic pathways with the observed cell death. Our data suggest that coralyne, which is known topoisomerase-I inhibitor, may be an attractive agent for photo-chemotherapeutic treatment of human skin cancers.