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 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.
4.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.
5.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.
6.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.
7.Accumulated Effects of 24 Hours Physical Activity,Sedentary Behavior,and Sleep on Cardiorespiratory Fitness in College Students.
Yun-Feng SONG ; Chi XU ; Kai-Xin LI ; Si-Jie TAN ; Yu-Gang QI
Acta Academiae Medicinae Sinicae 2025;47(2):155-163
Objective To explore the accumulated effects of physical activity,sedentary behavior,and sleep on cardiorespiratory fitness(CRF)among college students and provide effective measures for enhancing their CRF. Methods From May to June in 2023,223 college students aged 18 to 24 years old were recruited from Tianjin University of Science and Technology for a 24 hours activity behavior survey and CRF testing.Compositional analysis was employed to investigate the relationships of physical activity,sedentary behavior,and sleep with CRF.Isotemporal substitution models were established to predict the effects of substituting various activity behaviors on CRF.Results The proportion of time spent on moderate-to-vigorous physical activity(MVPA)was positively correlated with CRF of college students(β=6.40,P=0.002),while the proportion of time spent on sedentary behavior was negatively correlated with CRF(β=-3.02,P=0.004).Light physical activity(LPA)and sleep were not correlated with CRF(β=-1.06,P=0.504).Isotemporal substitution results for 15-min increments showed that replacing other activity behaviors with MVPA significantly increased the CRF of college students[SB:1.72 mL/(kg·min),95% CI=0.94-2.51;LPA:1.82 mL/(kg·min),95% CI=0.95-2.68;sleep:1.64 mL/(kg·min),95% CI=0.84-2.45].In the dose-response relationship from -30 min to 30 min,reallocating time from other behaviors to MVPA had greater adverse effect on CRF than reallocating time from MVPA to other behaviors.Among all the substitutions,replacing LPA with MVPA had the most beneficial effect on improving CRF.Additionally,a 5-min increment was considered the optimal tipping point for MVPA replacing other activities.Conclusions This study underscores the importance of participating in MVPA for improving the CRF of college students.The isotemporal substitution model provides clear goals for the allocation of time for these behaviors,aiding in future intervention measure development and policy-making.
Humans
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Sedentary Behavior
;
Sleep
;
Students
;
Cardiorespiratory Fitness
;
Exercise
;
Young Adult
;
Adolescent
;
Universities
;
Male
;
Female
8.Effects of Compositional Isotemporal Substitutions of 24 Hours Activity Behaviors on Novel Obesity Indicators in College Students.
Yun-Feng SONG ; Chi XU ; Si-Jie TAN ; Yu-Gang QI
Acta Academiae Medicinae Sinicae 2025;47(2):164-174
Objective To explore the effects of time reallocation among moderate-to-vigorous physical activity(MVPA),light physical activity(LPA),sedentary behavior(SB),and sleep on a body shape index(ABSI),body roundness index(BRI),conicity index(CI),and relative fat mass(RFM)of college students by the compositional isotemporal substitution method,thus providing measures for alleviating the obesity problem of college students. Methods Two hundred and ten college students(111 males and 99 females)aged 18-22 years old were recruited from Tianjin University of Science and Technology from April to June in 2023.Three-dimensional acceleration sensors were used to collect data of MVPA,LPA,SB,and sleep of college students.The body height,body weight,and waist circumference were measured,and four novel obesity indicators(ABSI,BRI,CI,and RFM)were calculated.The effects of substituting each activity behavior for 15 min on the obesity indicators were predicted,and the dose-effect relationship was explored at intervals of 5 min from -30 to 30 min.Results MVPA was negatively correlated with ABSI(β=-0.03,P=0.001),BRI(β=-0.27,P=0.049),CI(β=-0.10,P=0.001),and RFM(β=-9.95,P=0.004).LPA was negatively correlated with CI(β=-0.05,P=0.011)and RFM(β=-8.74,P=0.007).Neither SB nor sleep had correlations with ABSI,BRI,CI,and RFM.The results of 15 min isotemporal substitutions showed that increasing the MVPA time decreased the ABSI,BRI,CI,and RFM by 0.006-0.008,0.306-0.393,0.162-0.205,and 2.468-2.897,respectively.Decreasing the MVPA time increased the ABSI,BRI,CI,and RFM by 0.012-0.014,0.548-0.632,0.286-0.328,and 4.358-4.748,respectively.In the dose-effect relationship from -30 min to 30 min,MVPA was irreplaceable,and the negative benefits from substituting MVPA for other activity behaviors were much greater than the positive benefits from substituting MVPA for other activity behaviors.Conclusions Future research should take 24 hours activity behaviors as a whole.Increasing the time spent on MVPA and LPA and decreasing the time spent on SB is one of the effective ways to alleviate the obesity problem among college students.
Humans
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Male
;
Students
;
Female
;
Young Adult
;
Obesity
;
Sleep
;
Adolescent
;
Exercise
;
Universities
;
Sedentary Behavior
;
Body Mass Index
;
Body Weight
9.Establishment of amachine learning-based precision recruitment method at the county level
Xiaoyan FU ; Zihan ZHANG ; Fang ZHAO ; Chunlan ZHOU ; Wenbiao LIANG ; Cheng YU ; Yingzhi YAN ; Wei SI ; Weibin TAN ; Hui XUE
Chinese Journal of Blood Transfusion 2025;38(12):1752-1758
Objective: To establish a machine learning-based precision blood donor recruitment model at the county level and assess its generalizability and applicability. Methods: A retrospective study was conducted using blood donation and SMS recruitment data from the Taicang Branch of the Suzhou Blood Center between 2019 and 2024. Multiple machine learning algorithms were employed, including extreme gradient boosting, support vector machine, k-nearest neighbor, logistic regression, decision tree, random forest, and multilayer perceptron. These were combined with techniques such as synthetic minority oversampling, undersampling, and cost-sensitive learning (using MFE and MSFE loss functions). Model parameters were optimized through grid search to identify the best-performing model. Results: In a prospective comparative study against conventional methods, the machine learning models increased the recruitment success rate among high-willingness donors by an average of 129.15%, and the recruitment efficiency per SMS improved by 125.02% compared with the traditional method. Under full-scale SMS sending, the recruitment rate per SMS increased by 42.61%, and SMS sending efficiency improved by 31.77%, significantly enhancing recruitment performance. Conclusion: This study represents the first application of a machine learning-based precision donor recruitment model at the county-level in China. The precise recruitment framework not only improves recruitment efficiency and reduces recruitment costs but also demonstrates strong scalability and generalizability. It provides a scientific and feasible intelligent pathway to ensure the safety and sustainability of the blood supply.
10.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

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