1.Lysosomes as Regulators of Cancer Stemness and Drug Resistance
Fa-Xiao ZHOU ; Di-Ping YU ; Si-Qi TAN ; Hong-Yu DUAN ; Xiao-Ming WU
Progress in Biochemistry and Biophysics 2026;53(4):951-967
Cancer stem cells (CSCs) represent a distinct subpopulation of cells characterized by self-renewal capacity, differentiation potential, and critical roles in driving tumor progression, therapeutic resistance, recurrence, and maintenance of the tumor microenvironment. Targeting CSCs has emerged as a pivotal direction in cancer research, offering novel strategies to overcome drug resistance and prevent metastasis and relapse. Lysosomes, traditionally recognized as central organelles for intracellular degradation and recycling, are indispensable for cellular homeostasis. Dysregulation of lysosomal function is intimately linked to various diseases, including cancer. In tumors, aberrant lysosomal activity can promote malignant progression through mechanisms such as altering metabolic pathways, enhancing lysosomal exocytosis, modulating drug resistance, and interfering with autophagy-lysosomal pathways. Recent studies have underscored the involvement of lysosomes in regulating CSC properties. This review synthesizes findings on lysosomal regulation of CSCs through the following aspects. (1) Lysosomes exert complex and critical bidirectional control over CSC stemness maintenance through three degradation pathways that are dependent on their degradative function. (i) The lysophagy pathway. This pathway exhibits dual roles. Activation can sustain CSC functions; for instance, in glioblastoma, hypoxia upregulates Gal-8 via the STAT3/HIF1α signaling axis to induce autophagy, supporting stem cell survival. In head and neck squamous cell carcinoma, degradation of GSK3β activates the Wnt pathway, enhancing stemness. Conversely, this pathway can suppress stemness by degrading stemness-related proteins such as BMI-1 and OCT4A, thereby impairing CSC self-renewal capacity. (ii) Mitophagy pathway. In non-small cell lung cancer stem cells, mitophagy-related mechanisms, such as the accumulation of mitochondrial DNA (mtDNA) activating the TLR9-Notch1-AMPK signaling axis, have been shown to promote CSC proliferation. (iii) Autophagosome-dependent lysosomal degradation pathway. This pathway directly regulates stemness-related proteins in a bidirectional manner. Enhanced degradative function can promote CSC properties, exemplified by the degradation of NUMB to activate Notch signaling. Conversely, attenuated degradative function can also enhance stemness by stabilizing oncoproteins (e.g., protecting Frizzled-1 from degradation to sustain Wnt signaling) or preventing the degradation of tumor suppressors (e.g., inhibiting Notch degradation). (2) Constituent proteins of lysosomes, including membrane proteins and luminal acid hydrolases, participate in regulating CSC stemness. Regarding membrane proteins, LAMP2A facilitates chaperone-mediated autophagy to maintain stemness in glioblastoma and ovarian cancer. V-ATPase, by maintaining an acidic luminal environment, promotes proliferation and drug resistance in glioma stem cells. Among hydrolases, cathepsins B and L are highly expressed in pancreatic and ovarian cancers and correlate with poor prognosis. Furthermore, targeting lysosomes to induce lysosomal membrane permeabilization (LMP) triggers lysosome-mediated cell death, presenting a potential therapeutic strategy for eradicating CSCs.(3) The acidic luminal environment, single-membrane structure, and the presence of transmembrane transporters (e.g., ABCA3) enable lysosomes to passively trap or actively uptake and sequester chemotherapeutic drugs. Subsequent drug extrusion via exocytosis confers drug resistance. In CSCs, this lysosome-mediated drug sequestration, often cooperating with autophagy, establishes multimodal drug resistance. Therefore, targeting lysosomal function represents a potential strategy to overcome therapy resistance. The central role of lysosomes in regulating CSC stemness and resistance positions them as highly promising therapeutic targets. Strategies aimed at disrupting lysosomal function to selectively eliminate CSCs include: inhibiting the lysosome-autophagy system using agents like IITZ or lovastatin; inducing lysosomal membrane permeabilization (LMP) with compounds such as hexamethylene amiloride to compromise membrane stability; and disrupting the acidic luminal environment using drugs like siramesine or the K/H transport compound 2. In conclusion, lysosomes critically regulate CSC stemness maintenance and drug resistance through degradative pathways, membrane protein functions, luminal hydrolase activities, and drug sequestration mechanisms. This redefines the lysosome from a traditional “waste disposal unit” to a “signal integration center” in CSCs. The duality and context-dependency of lysosomal function in CSCs offer novel insights into the heterogeneity observed across different tumors. Targeting lysosomal vulnerabilities—such as inducing LMP, disrupting acidity, or blocking autophagic flux—provides a strategy to bypass canonical CSC resistance mechanisms and directly trigger cell death. This establishes the lysosome as a key target to overcome CSC-mediated therapy resistance, paving the way for developing diverse candidate drugs and innovative combination therapies in oncology.
2.Predictors of moderate, severe, and critical COVID-19 infection in a largely vaccinated kidney transplant recipient cohort during the Omicron era: the importance of timely booster vaccinations and early presentation to care
Cherie Le Si GAN ; Shimin Jasmine CHUNG ; Quan Yao HO ; Thuan Tong TAN ; Ban Hock TAN ; Ian Tatt LIEW ; Carolyn Shan-Yeu TIEN ; Sobhana THANGARAJU ; Terence KEE
Clinical Transplantation and Research 2025;39(1):46-54
Background:
Kidney transplant recipients (KTRs) are at risk of coronavirus disease 2019 (COVID-19) complications and mortality. This study examined factors associated with moderate, severe, or critical COVID-19 infection among KTRs during the Omicron-predominant period.
Methods:
This single-center retrospective study included KTRs aged ≥18 years diag-nosed with COVID-19 between January 1, 2022, and December 31, 2023. Mild infection was defined as symptomatic illness without lower respiratory tract infection (LRTI);moderate infection as LRTI without hypoxia; severe infection as oxygen saturation <94% on room air; and critical infection as respiratory failure, septic shock, or multiple organ dysfunction. We compared the characteristics of KTRs with asymptomatic or mild COVID-19 versus those with moderate to critical disease. Logistic regression analysis was performed to identify factors associated with moderate to critical illness.
Results:
Most KTRs (94.4%) had received three or more vaccine doses. Of 603 episodes of COVID-19 infection during the study period, 554 (91.9%) were asymptomatic or mild, while 49 (8.1%) were moderate to critical. Multivariate analysis revealed that older age (adjusted odds ratio [aOR], 1.037; 95% confidence interval [CI], 1.006–1.069) and longer symptom duration before seeking care (aOR, 1.288; 95% CI, 1.155–1.436) were associated with higher odds of moderate to critical disease. Protective factors included receiving a vaccine booster within the past year (aOR, 0.414; 95% CI, 0.212–0.809) and higher glomerular filtration rate (aOR, 0.971; 95% CI, 0.956–0.986).
Conclusions
KTRs should seek care early if infected with COVID-19 and keep their COVID-19 vaccine boosters updated within 1 year of the last dose.
3.A Study of Flow Sorting Lymphocyte Subsets to Detect Epstein-Barr Virus Reactivation in Patients with Hematological Malignancies.
Hui-Ying LI ; Shen-Hao LIU ; Fang-Tong LIU ; Kai-Wen TAN ; Zi-Hao WANG ; Han-Yu CAO ; Si-Man HUANG ; Chao-Ling WAN ; Hai-Ping DAI ; Sheng-Li XUE ; Lian BAI
Journal of Experimental Hematology 2025;33(5):1468-1475
OBJECTIVE:
To analyze the Epstein-Barr virus (EBV) load in different lymphocyte subsets, as well as clinical characteristics and outcomes in patients with hematologic malignancies experiencing EBV reactivation.
METHODS:
Peripheral blood samples from patients were collected. B, T, and NK cells were isolated sorting with magnetic beads by flow cytometry. The EBV load in each subset was quantitated by real-time quantitative polymerase chain reaction (RT-qPCR). Clinical data were colleted from electronic medical records. Survival status was followed up through outpatient visits and telephone calls. Statistical analyses were performed using SPSS 25.0.
RESULTS:
A total of 39 patients with hematologic malignancies were included, among whom 35 patients had undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT). The median time to EBV reactivation was 4.8 months (range: 1.7-57.1 months) after allo-HSCT. EBV was detected in B, T, and NK cells in 20 patients, in B and T cells in 11 patients, and only in B cells in 4 patients. In the 35 patients, the median EBV load in B cells was 2.19×104 copies/ml, significantly higher than that in T cells (4.00×103 copies/ml, P <0.01) and NK cells (2.85×102 copies/ml, P <0.01). Rituximab (RTX) was administered for 32 patients, resulting in EBV negativity in 32 patients with a median time of 8 days (range: 2-39 days). Post-treatment analysis of 13 patients showed EBV were all negative in B, T, and NK cells. In the four non-transplant patients, the median time to EBV reactivation was 35 days (range: 1-328 days) after diagnosis of the primary disease. EBV was detected in one or two subsets of B, T, or NK cells, but not simultaneously in all three subsets. These patients received a combination chemotherapy targeting at the primary disease, with 3 patients achieving EBV negativity, and the median time to be negative was 40 days (range: 13-75 days).
CONCLUSION
In hematologic malignancy patients after allo-HSCT, EBV reactivation commonly involves B, T, and NK cells, with a significantly higher viral load in B cells compared to T and NK cells. Rituximab is effective for EBV clearance. In non-transplant patients, EBV reactivation is restricted to one or two lymphocyte subsets, and clearance is slower, highlighting the need for prompt anti-tumor therapy.
Humans
;
Hematologic Neoplasms/virology*
;
Herpesvirus 4, Human/physiology*
;
Epstein-Barr Virus Infections
;
Hematopoietic Stem Cell Transplantation
;
Virus Activation
;
Lymphocyte Subsets/virology*
;
Flow Cytometry
;
Killer Cells, Natural/virology*
;
Male
;
Female
;
B-Lymphocytes/virology*
;
Viral Load
;
Adult
;
T-Lymphocytes/virology*
;
Middle Aged
4.Hydroxysafflor Yellow A Ameliorates the Replicative Senescence of Human Umbilical Cord Mesenchymal Stem Cells by Suppressing Oxidative Stress.
Si-Yun WANG ; Qi ZHU ; Chun-Xia TAN ; Fang LU ; Tao LU
Journal of Experimental Hematology 2025;33(5):1507-1515
OBJECTIVE:
To investigate the effects and mechanisms of hydroxysafflor yellow A (HSYA) on replicative senescence in human umbilical cord mesenchymal stem cells (hUC-MSCs).
METHODS:
hUC-MSCs were cultured to construct a replicative senescence model through continuous amplification in vitro. Cells at passage 2 served as the control group, while cells at passage 10 were designated as the senescence group. The senescent cells were cultured in a culture medium containing HSYA. Cell viability was detected by the CCK-8 assay, and cell confluence was analyzed using the Incucyte S3 live-cell analysis system. The optimal concentration and time point were determined and utilized for subsequent experiments. Senescent cells were pretreated with 0.01 mg/ml HSYA, and the proportion of senescence-associated β-galactosidase (SA-β-gal) positive cells was detected to assess the senescence state. The relative telomere length was detected by qPCR. Reactive oxygen species (ROS) levels were measured using the fluorescent probe DCFH-DA. Mitochondrial membrane potential was assessed by JC-1 staining. The expression of p53, p16, p21, OCT4, and SOX2 genes was detected by qPCR. The expression of p16, p53, OCT4, and SOX2 proteins was analyzed by Western blot.
RESULTS:
HSYA significantly decreased the SA-β-gal positive staining rate, inhibited telomere attrition, reduced the ROS accumulation, increased mitochondrial membrane potential in senescent cells. Additionally, HSYA downregulated the expression of p53 and p16, and upregulated the expression of OCT4. HSYA decreased p16 protein level and increased OCT4 and SOX2 protein levels.
CONCLUSION
HSYA may ameliorate replicative senescence in hUC-MSCs by modulating the p53 and p16 signaling pathways and suppressing oxidative stress.
Humans
;
Mesenchymal Stem Cells/drug effects*
;
Cellular Senescence/drug effects*
;
Chalcone/pharmacology*
;
Oxidative Stress/drug effects*
;
Quinones/pharmacology*
;
Umbilical Cord/cytology*
;
Reactive Oxygen Species/metabolism*
;
Cells, Cultured
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Cyclin-Dependent Kinase Inhibitor p16/metabolism*
;
Tumor Suppressor Protein p53/metabolism*
;
Membrane Potential, Mitochondrial
;
Cell Proliferation
5.Cytomegalovirus Gastritis Induced by Immune Checkpoint Inhibitors Treatment in Lung Adenocarcinoma: A Case Report.
Xiaoyan SI ; Bei TAN ; Xin CHENG ; Mengzhao WANG ; Xiaotong ZHANG ; Li ZHANG
Chinese Journal of Lung Cancer 2025;28(8):644-646
Immune checkpoint inhibitors (ICIs) have been approved for the treatment of a variety of solid tumors and hematological malignancies. Adverse reactions caused by ICIs have been gradually focused on. Cytomegalovirus (CMV) gastritis after ICIs treatment is relatively rare. Here we reported a case of advanced lung adenocarcinoma who experienced recurrent upper abdominal pain and vomiting after Pembrolizumab treatment. CMV gastritis was diagnosed through gastroscopy. The patient's symptoms improved after antiviral treatment. During the treatment of ICIs, attention should be paid to the differential diagnosis of upper abdominal pain symptoms, and vigilance should be maintained against CMV gastritis. It is difficult to differentiate CMV gastritis and immune-related gastritis judging from symptoms, and gastroscopy is important for differential diagnosis.
.
Humans
;
Adenocarcinoma of Lung/drug therapy*
;
Cytomegalovirus/physiology*
;
Cytomegalovirus Infections
;
Gastritis/diagnosis*
;
Immune Checkpoint Inhibitors/therapeutic use*
;
Lung Neoplasms/drug therapy*
6.Improvement Effect of Sofalcone on Alleviates Nonsteroidal Anti-inflammatory Drug-induced Small Intestinal Mucosal Injury in Rats by RIPK1/RIPK3/MLKL Signaling Pathway
Jie TAN ; Yuping CAO ; Junxian WANG ; Si CHEN
Herald of Medicine 2025;44(6):854-861
Objective To investigate the protective effects and possible mechanisms of sofalcone on small intestinal mucosal damage induced by nonsteroidal anti-inflammatory drugs(NSAIDs)in rats.Methods In the first group of animal experiments,rats were randomly divided into five groups:normal control group,diclofenac group(diclofenac 7.5 mg·kg-1),and sofalcone high-doses groups(sofalcone 10 mg·kg-1+diclofenac 7.5 mg·kg-1),sofalcone medium-doses groups(sofalcone 5 mg·kg-1+diclofenac 7.5 mg·kg-1),and sofalcone low-doses groups(sofalcone 2 mg·kg-1+diclofenac 7.5 mg·kg-1).Each group received daily gavage for seven days.Serum D-lactate levels were measured,and histological damage to the small intestine was assessed through HE staining and pathological scoring.In the second group,rats were separated into three groups:normal control group,diclofenac group(diclofenac 7.5 mg·kg-1),and sofalcone group(sofalcone 2 mg·kg-1+diclofenac 7.5 mg·kg-1).Concurrently,the rats'body mass,24-hour diet,and water intake were monitored.Additionally,serum levels of pro-inflammatory cytokines such as IL-6,IFN-γ,TNF-α,inflammatory markers CRP and D-lactate,as well as measurements of tissue reactive oxygen species(ROS),lactate dehydrogenase(LDH),and mitochondrial membrane potential were conducted using appropriate kits.Western blotting was applied to assess the expression levels of intercellular junction proteins(Occludin,Claudin-1,α-Catenin),programmed necrosis pathway-associated proteins including receptor-interacting protein kinase 1(RIPK1),RIPK3,and mixed lineage kinase domain-like pseudokinase(MLKL)along with p-MLKL.Results In the first experiment,the diclofenac group exhibited significant histological damage to the small intestine,with elevated levels of D-lactic acid and pathological scores compared to the normal control group(P<0.01).Following intervention with sofalcone,both the histological damage and the levels of D-lactic acid and pathological scores in the small intestine were notably reduced(P<0.05 or P<0.01).However,there was no substantial difference in pathological scores among different doses of sofaclone groups(P>0.05).In the second experiment,compared with normal control group,rats in the diclofenac group showed decreased body mass,24-hour average diet and water intake,along with elevated levels of IL-6,IFN-γ,TNF-α,CRP,D-lactic acid,tissue ROS,LDH activity,RIPK1,RIPK3,and p-MLKL/MLKL protein expression levels,as well as mitochondrial membrane potential(P<0.05 or P<0.01).Moreover,Occludin,Claudin-1,and α-Catenin protein expression levels were reduced(P<0.05 or P<0.01).Following sofalcone intervention,the previously mentioned parameters were reversed(P<0.05 or P<0.01).Notably,there was no statistically significant difference observed in the reduction of RIPK1 protein expression(P>0.05).Conclusions Sofalcone reduces NSAID-induced small intestinal mucosal injury in rats by inhibiting the RIPK1/RIPK3/MLKL-dependent programmed necrosis pathway.
7.A Rare Normal Variant with an Unusual Presentation on a Male Mammogram:A Case Report
Victoria Kai Lin TAY ; Si YING TAN ; Chow Yin WONG ; Lester Chee Hao LEONG
Journal of the Korean Society of Radiology 2025;86(1):160-165
The sternalis muscle is a rare supernumerary muscle representing a normal anatomical variant in the anterior thoracic musculature. Due to wide variation in its morphology and relative unfamiliarity among radiologists, it has been implicated in the misdiagnosis of breast masses on mammography. A 23-year-old male with no significant medical history was referred to our institution for further management of painless bilateral breast enlargement since adolescence. Physical examination revealed breasts of slightly prominent size but there was no palpable breast lump. Mammography work-up found symmetrical, well-defined soft tissue masses projected over the posteromedial aspect of both breasts. Imaging findings were consistent with bilateral sternalis muscles, unusually hypertrophic in size due to intense upper body weight training by the patient. This case highlights the importance of recognizing the usual and unusual presentations of the sternalis muscles on mammography to avoid any unnecessary work-up.
8.Predictors of moderate, severe, and critical COVID-19 infection in a largely vaccinated kidney transplant recipient cohort during the Omicron era: the importance of timely booster vaccinations and early presentation to care
Cherie Le Si GAN ; Shimin Jasmine CHUNG ; Quan Yao HO ; Thuan Tong TAN ; Ban Hock TAN ; Ian Tatt LIEW ; Carolyn Shan-Yeu TIEN ; Sobhana THANGARAJU ; Terence KEE
Clinical Transplantation and Research 2025;39(1):46-54
Background:
Kidney transplant recipients (KTRs) are at risk of coronavirus disease 2019 (COVID-19) complications and mortality. This study examined factors associated with moderate, severe, or critical COVID-19 infection among KTRs during the Omicron-predominant period.
Methods:
This single-center retrospective study included KTRs aged ≥18 years diag-nosed with COVID-19 between January 1, 2022, and December 31, 2023. Mild infection was defined as symptomatic illness without lower respiratory tract infection (LRTI);moderate infection as LRTI without hypoxia; severe infection as oxygen saturation <94% on room air; and critical infection as respiratory failure, septic shock, or multiple organ dysfunction. We compared the characteristics of KTRs with asymptomatic or mild COVID-19 versus those with moderate to critical disease. Logistic regression analysis was performed to identify factors associated with moderate to critical illness.
Results:
Most KTRs (94.4%) had received three or more vaccine doses. Of 603 episodes of COVID-19 infection during the study period, 554 (91.9%) were asymptomatic or mild, while 49 (8.1%) were moderate to critical. Multivariate analysis revealed that older age (adjusted odds ratio [aOR], 1.037; 95% confidence interval [CI], 1.006–1.069) and longer symptom duration before seeking care (aOR, 1.288; 95% CI, 1.155–1.436) were associated with higher odds of moderate to critical disease. Protective factors included receiving a vaccine booster within the past year (aOR, 0.414; 95% CI, 0.212–0.809) and higher glomerular filtration rate (aOR, 0.971; 95% CI, 0.956–0.986).
Conclusions
KTRs should seek care early if infected with COVID-19 and keep their COVID-19 vaccine boosters updated within 1 year of the last dose.
10.Selection and validation of reference genes for quantitative real-time PCR analysis in Tujia medicine Xuetong.
Qian XIAO ; Chen-Si TAN ; Jiang ZENG ; Yuan-Shu XU ; Tian-Hao FU ; Lu-Yun NING ; Wei WANG
China Journal of Chinese Materia Medica 2025;50(3):682-692
Tujia ethnic group medicine Xuetong is derived from Kadsura heteroclita, the stem of which has the medicinal value for anti-rheumatoid arthritis, liver protection, anti-tumor, anti-oxidation effects, and has been widely used in Hunan and Guangdong in China. The selection of reliable and stable reference genes is the basis for subsequent molecular research on K. heteroclita. In this study, GAPDH, TUA, Actin, UBQ, EF-1α, 18S-rRNA, CYP, UBC, TUB, H2A, and RPL were selected as candidate reference genes in Kadsura heteroclita. The gene expression levels of the 11 candidate reference genes of K. heteroclita in its 6 different parts(stem-inside of the cambium, stem-outside of the cambium, fruit, flower, root, and leaf) and under different intervention conditions [drought stress, salt stress, and methyl jasmonate(MeJA) treatment] were detected by quantitative real-time polymerase chain reaction(qRT-PCR). The expression stability of the 11 candidate reference genes was comprehensively analyzed and evaluated by geNorm, NormFinder, ΔCT algorithm, and RefFinder software. The results showed that the expression of UBC and RPL was relatively stable in 6 different parts, and UBC and GAPDH genes were relatively stable under different intervention conditions. To verify the reliability of reference genes for K. heteroclita, this study further examined the relative expression levels of KhFPS, KhIDI, KhCAS, KhSQE, KhSQS, KhSQS-2, KhHMGS, KhHMGR, KhMVD, KhMVK, KhDXR, KhDXS, KhPMVK, and KhGGPS in different parts and under different intervention conditions, which might relate to the synthesis of the main component(Xuetongsu) of K. heteroclita. The results showed that with UBC and RPL or UBC and GAPDH as the reference genes, the expression trends of these 14 genes were basically consistent in different parts or under different intervention conditions for K. heteroclita. In conclusion, UBC can be used as a reference gene of K. heteroclita for its different parts and different intervention conditions, which lays a foundation for further research on the biosynthetic pathway of main components in K. heteroclita.
Real-Time Polymerase Chain Reaction/methods*
;
Reference Standards
;
Gene Expression Regulation, Plant
;
Gene Expression Profiling
;
Plant Proteins/metabolism*
;
Drugs, Chinese Herbal

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