CRISPR-mediated Sox9 activation and RelA inhibition enhance cell therapy for osteoarthritis.

Osteoarthritis (OA) is a painful and debilitating disease affecting over 500 million people worldwide. Intraarticular injection of mesenchymal stromal cells (MSCs) shows promise for the clinical treatment of OA, but the lack of consistency in MSC preparation and application makes it difficult to further optimize MSC therapy and to properly evaluate the clinical outcomes. In this study, we used Sox9 activation and RelA inhibition, both mediated by the CRISPR-dCas9 technology simultaneously, to engineer MSCs with enhanced chondrogenic potential and downregulated inflammatory responses. We found that both Sox9 and RelA could be fine-tuned to the desired levels, which enhances the chondrogenic and immunomodulatory potentials of the cells. Intraarticular injection of modified cells significantly attenuated cartilage degradation and palliated OA pain compared with the injection of cell culture medium or unmodified cells. Mechanistically, the modified cells promoted the expression of factors beneficial to cartilage integrity, inhibited the production of catabolic enzymes in osteoarthritic joints, and suppressed immune cells. Interestingly, a substantial number of modified cells could survive in the cartilaginous tissues including articular cartilage and meniscus. Together, our results suggest that CRISPR-dCas9-based gene regulation is useful for optimizing MSC therapy for OA.

Loss of miR-204 and miR-211 shifts osteochondral balance and causes temporomandibular joint osteoarthritis.

Temporomandibular joint (TMJ) osteoarthritis (OA) is a common type of TMJ disorders causing pain and dysfunction in the jaw and surrounding tissues. The causes for TMJ OA are unknown and the underlying mechanism remains to be identified. In this study, we generated genetically-modified mice deficient of two homologous microRNAs, miR-204 and miR-211, both of which were confirmed by in situ hybridization to be expressed in multiple TMJ tissues, including condylar cartilage, articular eminence, and TMJ disc. Importantly, the loss-of-function of miR-204 and miR-211 caused an age-dependent progressive OA-like phenotype, including cartilage degradation and abnormal subchondral bone remodeling. Mechanistically, the TMJ joint deficient of the two microRNAs demonstrated a significant accumulation of RUNX2, a protein directly targeted by miR-204/-211, and upregulations of ß-catenin, suggesting a disrupted balance between osteogenesis and chondrogenesis in the TMJ, which may underlie TMJ OA. Moreover, the TMJ with miR-204/-211 loss-of-function displayed an aberrant alteration in both collagen component and cartilage-degrading enzymes and exhibited exacerbated orofacial allodynia, corroborating the degenerative and painful nature of TMJ OA. Together, our results establish a key role of miR-204/-211 in maintaining the osteochondral homeostasis of the TMJ and counteracting OA pathogenesis through repressing the pro-osteogenic factors including RUNX2 and ß-catenin.

Genetic abnormalities assist in pathological diagnosis and EBV-positive cell density impact survival in Chinese angioimmunoblastic T-cell lymphoma patients.

Objective: To explore the application of genetic abnormalities in the diagnosis of angioimmunoblastic T-cell lymphoma (AITL) and the reliable pathological prognostic factors. Methods: This study included 53 AITL cases, which were reviewed for morphological patterns, immunophenotypes, presence of Hodgkin and Reed-Sternberg (HRS)-like cells, and co-occurrence of B cell proliferation. The Epstein-Barr virus (EBV)-positive cells in tissues were counted, and cases were classified into "EBV encoded RNA (EBER) high-density" group if >50/HPF. Targeted exome sequencing was performed. Results: Mutation data can assist AITL diagnosis: 1) with considerable HRS-like cells (20 cases): RHOA mutated in 14 cases (IDH2 co-mutated in 3 cases, 4 cases with rare RHOA mutation), TET2 was mutated in 5 cases (1 case co-mutated with DNMT3A), and DNMT3A mutated in 1 case; 2) accompanied with B cell lymphoma (7 cases): RHOA mutated in 4 cases (1 case had IDH2 mutation), TET2 mutated in 2 cases and DNMT3A mutated in 1 case; 3) mimic peripheral T cell lymphoma, not otherwise specified (5 cases): RHOA mutated in 2 cases (IDH2 co-mutated in 1 case), TET2 mutated in 3 cases, and DNMT3A mutated in 1 case; 4) pattern 1 (1 case), RHOA and TET2 co-mutated. Besides RHOAG17V (30/35), rare variant included RHOAK18N, RHOAR68H, RHOAC83Y, RHOAD120G and RHOAG17del, IDH2R172 co-mutated with IDH2M397V in one case. There were recurrent mutations of FAT3, PCLO and PIEZO1 and genes of epigenetic remodeling, T-cell activation, APC and PI3K/AKT pathway. EBER high-density independently indicated adverse overall survival and progression-free survival (P=0.046 and P=0.008, Kaplan-Meier/log-rank). Conclusions: Over half AITL cases might be confused in diagnosis for certain conditions without mutation data. Targeted exome sequencing with a comprehensive panel is crucial to detect both hot-spot and rare mutation variants for RHOA and IDH2 and other recurrent mutated genes in addition to TET2 and DNMT3A. EBER high-density independently indicated adverse survival.

Genetic alteration of Chinese patients with rectal mucosal melanoma.

BACKGROUND: Rectal mucosal melanoma (RMM) is a rare and highly aggressive disease with a poor prognosis. Due to the rarity of RMM, there are few studies focusing on its genetic mechanism. This retrospective study aimed to analyze the genetic spectrum and prognosis of RMM in China and lay a foundation for targeted therapy. METHODS: 36 patients with primary RMM from Peking University Cancer Hospital were enrolled in this study. The Next-generation sequencing (NGS) data of the tumor samples were fitted into the TruSight™ Oncology 500 (TSO500) Docker pipeline to detect genomic variants. Then, the univariate and multivariate Cox hazard analysis were performed to evaluate the correlations of the variants with the overall survival (OS), along with Kaplan-Meier and log-rank test to determine their significance. RESULTS: BRAF mutations, NRG1 deletions and mitotic index were significant prognostic factors in the univariate analysis. In multivariable analysis of the OS-related prognostic factors in primary RMM patients, it revealed 2 significant alterations: BRAF mutations [HR 7.732 (95%CI: 1.735-34.456), P = 0.007] and NRG1 deletions [HR 14.976 (95%CI: 2.305-97.300), P = 0.005]. CONCLUSIONS: This is the first study to show genetic alterations exclusively to Chinese patients with RMM. We confirmed genetic alterations of RMM differ from cutaneous melanoma (CM). Our study indicates that BRAF and NRG1 were correlated with a poor prognostic of RMM and may be potential therapeutic targets for RMM treatment.

Exercise Capacity and Quality of Life in Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease with a high mortality rate that can be divided into different groups according to etiology and prognosis. Few studies have investigated differences in the exercise capacity and quality of life (QOL) among the different groups of PAH patients. Therefore, we aimed to (1) compare the hemodynamic exercise responses between patients with idiopathic pulmonary arterial hypertension (IPAH) and PAH associated with other diseases (APAH), and (2) determine the factors associated with exercise capacity in patients with PAH. METHODS: Six patients diagnosed with IPAH and eight with APAH [congenital heart disease (CHD)-dominant PAH] were included in this study. The main outcome measures included body composition, exercise capacity, hemodynamic measurements, physical activity levels, fatigue severity, and QOL. RESULTS: The CHD-dominant PAH group had a significantly lower predicted peak oxygen consumption (VO2pred %), pressure of end-tidal carbon dioxide at the peak and at anaerobic threshold (PETCO2peak and PETCO2@AT), and significantly elevated ventilatory equivalent (VE/VCO2slope and VE/VCO2@AT) compared with the IPAH group. Multiple regression analysis indicated that PETCO2@AT was significantly associated with either VO2peak (ß = 0.805, adjusted R2 = 0.619, p = 0.001) or 6-minute walk distance (ß = 0.816, adjusted R2 = 0.638, p < 0.001). CONCLUSIONS: Patients with CHD-dominant PAH had poor exercise capacity and exercise responses compared to those with IPAH. Evaluating exercise capacity and the patient response to exercise using cardiopulmonary exercise testing is increasingly important in view of the etiology of PAH.

The TOR complex 1 is a direct target of Rho1 GTPase.

The TOR complex 1 (TORC1) in yeast is regulated by various stress conditions. However, the underlying mechanism is poorly understood. In this study, we show that stresses affect TORC1 function through Rho1, a member of Rho family GTPases. Upon activation by stresses, Rho1 binds directly to Kog1, a unique component of TORC1, resulting in downregulation of TORC1 activity and disruption of its membrane association. The binding also triggers the release and activation of the Tap42-2A phosphatase, a major effector of TORC1 that resides on the complex. Rapamycin and caffeine also induce Rho1 activation. While the two agents inhibit TOR directly, their effects on TORC1 signaling are largely dependent on Rho1 activation. Our findings demonstrate that TORC1 acts both upstream and downstream of Rho1 GTPase, unveiling a mechanism that integrates stress and nutrient signals to coordinate Rho1-mediated spatial expansion and TORC1-dependent mass increase.

Kindlin-2 Association with Rho GDP-Dissociation Inhibitor α Suppresses Rac1 Activation and Podocyte Injury.

Alteration of podocyte behavior is critically involved in the development and progression of many forms of human glomerular diseases. The molecular mechanisms that control podocyte behavior, however, are not well understood. Here, we investigated the role of Kindlin-2, a component of cell-matrix adhesions, in podocyte behavior in vivo Ablation of Kindlin-2 in podocytes resulted in alteration of actin cytoskeletal organization, reduction of the levels of slit diaphragm proteins, effacement of podocyte foot processes, and ultimately massive proteinuria and death due to kidney failure. Through proteomic analyses and in vitro coimmunoprecipitation experiments, we identified Rho GDP-dissociation inhibitor α (RhoGDIα) as a Kindlin-2-associated protein. Loss of Kindlin-2 in podocytes significantly reduced the expression of RhoGDIα and resulted in the dissociation of Rac1 from RhoGDIα, leading to Rac1 hyperactivation and increased motility of podocytes. Inhibition of Rac1 activation effectively suppressed podocyte motility and alleviated the podocyte defects and proteinuria induced by the loss of Kindlin-2 in vivo Our results identify a novel Kindlin-2-RhoGDIα-Rac1 signaling axis that is critical for regulation of podocyte structure and function in vivo and provide evidence that it may serve as a useful target for therapeutic control of podocyte injury and associated glomerular diseases.

CDK4/6 inhibitor-SHR6390 exerts potent antitumor activity in esophageal squamous cell carcinoma by inhibiting phosphorylated Rb and inducing G1 cell cycle arrest.

BACKGROUND: Cell cycle dysregulation is common in human malignancies, and CDK4/6 inhibitors targeting cell cycle have potential antitumor activity. SHR6390 is a novel small molecule inhibitor specifically targeting the CDK4/6 pathway. However, the role of SHR6390 in esophageal squamous cell carcinoma (ESCC) remains unknown, which will be investigated in our study. METHODS: Eca 109, Eca 9706, and KYSE-510 ESCC cell lines were chosen for further analysis. The effect of SHR6390 on cell viability, cell cycle and cell apoptosis, the status of kinases in Cyclin D1-CDK4/6-Rb pathway were determined by MTS assay, flow cytometry, and western blotting, respectively. Cell-derived and patient-derived xenografts were established to investigate the effects of drugs in vivo. RESULTS: SHR6390 could suppress cell proliferation in vitro cell lines and inhibit tumor growth in vivo PDX models with different drug susceptibility. The effective treatment of SHR6390 induced the inhibition of phosphorylated Rb and cell cycle arrest at G1 phase both in cell lines and in xenografts. SHR6390 combined with paclitaxel or cisplatin offered synergistic inhibitory effects in cell-derived xenografts especially in Eca 9706 xenografts which showed relative lower sensitivity of SHR6390 single. Moreover, low expression of CDK6 and/or high expression of Cyclin D1 might be associated with high sensitivity of SHR6390, which would be validated in the future. CONCLUSIONS: CDK4/6 inhibitor-SHR6390 exerted potential antitumor activity against ESCC cell lines and xenografts, and evaluation of CDK6 and Cyclin D1 expressions might be helpful to select patients beneficial from SHR6390, which provided evidences for future clinical trials.

Impaired bone homeostasis in amyotrophic lateral sclerosis mice with muscle atrophy.

There is an intimate relationship between muscle and bone throughout life. However, how alterations in muscle functions in disease impact bone homeostasis is poorly understood. Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease characterized by progressive muscle atrophy. In this study we analyzed the effects of ALS on bone using the well established G93A transgenic mouse model, which harbors an ALS-causing mutation in the gene encoding superoxide dismutase 1. We found that 4-month-old G93A mice with severe muscle atrophy had dramatically reduced trabecular and cortical bone mass compared with their sex-matched wild type (WT) control littermates. Mechanically, we found that multiple osteoblast properties, such as the formation of osteoprogenitors, activation of Akt and Erk1/2 pathways, and osteoblast differentiation capacity, were severely impaired in primary cultures and bones from G93A relative to WT mice; this could contribute to reduced bone formation in the mutant mice. Conversely, osteoclast formation and bone resorption were strikingly enhanced in primary bone marrow cultures and bones of G93A mice compared with WT mice. Furthermore, sclerostin and RANKL expression in osteocytes embedded in the bone matrix were greatly up-regulated, and ß-catenin was down-regulated in osteoblasts from G93A mice when compared with those of WT mice. Interestingly, calvarial bone that does not load and long bones from 2-month-old G93A mice without muscle atrophy displayed no detectable changes in parameters for osteoblast and osteoclast functions. Thus, for the first time to our knowledge, we have demonstrated that ALS causes abnormal bone remodeling and defined the underlying molecular and cellular mechanisms.

[Adult-onset generalized autoimmune enteropathy involving small intestine and colon: report of a case and review of literature].

OBJECTIVE: To investigate the clinicopathologic features of adult-onset autoimmune enteropathy (AIE). METHODS: A case of adult-onset AIE was described along with a literature review. RESULTS: A 41-year-old male patient was admitted for intractable diarrhea for more than three months despite of any dietary restriction or anti-inflammatory therapy. Fat globule was observed by stool examination and Sudan III staining of the stool was positive. Enteroclysis showed weak movement and few plica of small intestine, while colonoscopy appeared normal. Small bowel biopsies revealed villus atrophy and increased crypt apoptotic bodies and lymphocytic infiltration in deep crypt. Although without significant surface intro-epithelial lymphocytosis, there were a large number of monocytes, lymphocytes, plasmacytes and neutrophilic granulocytes infiltrating in the lamina propria. Morphologically, the colonic mucous was similar to the small intestine although cryptitis and crypt abscess were significant in the former. Serum IgG anti-goblet cell antibody was demonstrated by indirect immunofluorescence. Other causes of diarrhea were excluded on the base of medical history, histopathology and other accessory examinations before the diagnosis of AIE was made. The patient had a complete remission after steroid treatment without recurrence for eight months during the follow-up even after steroid withdrawal for five months. CONCLUSIONS: AIE is exceedingly rare and timely diagnosis is important for successful therapy. Histological differential diagnoses should include ulcerative colitis, celiac disease, lymphocytic colitis, etc. The final diagnosis should be based on histological examination combined with the patient history, clinical manifestation, endoscopy finding and serological testing.

Regulation of mammalian target of rapamycin complex 1 by Bcl-2 and Bcl-XL proteins.

Mammalian target of rapamycin complex 1 (mTORC1) is a key regulator of cell growth and metabolism. Its activity is controlled by various types of signals, including growth factors, nutrients, and stresses. In this study, we show that changes in expression levels of two antiapoptotic proteins, Bcl-2 and Bcl-XL, also affect mTORC1 signaling activity. In cells overexpressing Bcl-XL, mTORC1 activity is increased and becomes less sensitive to growth factor or nutrient conditions. In contrast, reduction in expression levels of the two antiapoptotic proteins inhibits mTORC1 signaling activity. Our results suggest that the effect of Bcl-2 and Bcl-XL on mTORC1 is mediated by FKBP38, an inhibitor of mTORC1. The two proteins compete with mTORC1 for FKBP38 binding and hence alter mTORC1 activity. This study reveals a novel cross-talk between Bcl-2/XL and mTORC1 signaling, which is likely to contribute to cancer development.

Critical role of AKT protein in myeloma-induced osteoclast formation and osteolysis.

Abnormal osteoclast formation and osteolysis are the hallmarks of multiple myeloma (MM) bone disease, yet the underlying molecular mechanisms are incompletely understood. Here, we show that the AKT pathway was up-regulated in primary bone marrow monocytes (BMM) from patients with MM, which resulted in sustained high expression of the receptor activator of NF-κB (RANK) in osteoclast precursors. The up-regulation of RANK expression and osteoclast formation in the MM BMM cultures was blocked by AKT inhibition. Conditioned media from MM cell cultures activated AKT and increased RANK expression and osteoclast formation in BMM cultures. Inhibiting AKT in cultured MM cells decreased their growth and ability to promote osteoclast formation. Of clinical significance, systemic administration of the AKT inhibitor LY294002 blocked the formation of tumor tissues in the bone marrow cavity and essentially abolished the MM-induced osteoclast formation and osteolysis in SCID mice. The level of activating transcription factor 4 (ATF4) protein was up-regulated in the BMM cultures from multiple myeloma patients. Adenoviral overexpression of ATF4 activated RANK expression in osteoclast precursors. These results demonstrate a new role of AKT in the MM promotion of osteoclast formation and bone osteolysis through, at least in part, the ATF4-dependent up-regulation of RANK expression in osteoclast precursors.

[Clinicopathologic features and prognosis of primary bone anaplastic large cell lymphoma].

OBJECTIVE: To study the clinicopathologic features, differential diagnosis and prognosis of primary bone anaplastic large cell lymphoma(ALCL). METHODS: Twelve patients diagnosed with primary bone ALCL were retrospectively reviewed. The clinicopathologic features, immunohistochemic findings and results of in situ hybridization for EB virus were analyzed. RESULTS: Of the 12 patients, the male-to-female was 7: 5 with a median age of 17.5 years (range from 9 to 64 years). Bone pain was the presenting symptom in all patients. Radiographic examination demonstrated solitary osteolytic lesion in 8 patients and multiple lesions in the rest 4 patients. Spine (7 cases) was the most common site to be involved, followed by ilium (5 cases), sacrum (2 cases), humerus (1 case) and collarbone (1 case). Ten patients were available with the follow-up data including 5 ALK-positive and 5 ALK-negative patients, and the follow-up time was 2 to 47 months. Interestingly, the 3 dead patients were ALK-negative whereas 5 of 7 ALK-positive patients achieved remission. CONCLUSIONS: Primary bone ALCL is a rare type of non-Hodgkin lymphoma and it more frequently involves the axial skeleton. Boys and young males are more commonly affected. Patients usually present at an early stage and have a relatively favorable prognosis. Expression of ALK protein may be associated with a favorable prognosis in primary bone ALCL.

Nerve growth factor receptor limits inflammation to promote remodeling and repair of osteoarthritic joints.

Osteoarthritis (OA) is a painful, incurable disease affecting over 500 million people. Recent clinical trials of the nerve growth factor (NGF) inhibitors in OA patients have suggested adverse effects of NGF inhibition on joint structure. Here we report that nerve growth factor receptor (NGFR) is upregulated in skeletal cells during OA and plays an essential role in the remodeling and repair of osteoarthritic joints. Specifically, NGFR is expressed in osteochondral cells but not in skeletal progenitor cells and induced by TNFα to attenuate NF-κB activation, maintaining proper BMP-SMAD1 signaling and suppressing RANKL expression in mice. NGFR deficiency hyper-activates NF-κB in murine osteoarthritic joints, which impairs bone formation and enhances bone resorption as exemplified by a reduction in subchondral bone and osteophytes. In human OA cartilage, NGFR is also negatively associated with NF-κB activation. Together, this study suggests a role of NGFR in limiting inflammation for repair of diseased skeletal tissues.

Nerve Growth Factor Receptor Limits Inflammation to Promote Remodeling and Repair of Osteoarthritic Joints.

Osteoarthritis (OA) is a painful, incurable disease affecting over 500 million people. The need for relieving OA pain is paramount but inadequately addressed, partly due to limited understandings of how pain signaling regulates non-neural tissues. Here we report that nerve growth factor receptor (NGFR) is upregulated in skeletal cells during OA and plays an essential role in the remodeling and repair of osteoarthritic joints. Specifically, NGFR is expressed in osteochondral cells but not in skeletal progenitor cells and induced by TNFα to attenuate NF-κB activation, maintaining proper BMP-SMAD1 signaling and suppressing RANKL expression. NGFR deficiency hyper-activates NF-κB in murine osteoarthritic joints, which impairs bone formation and enhances bone resorption as exemplified by a reduction in subchondral bone and osteophytes. In human OA cartilage, NGFR is also negatively associated with NF-κB activation. Together, this study uncovers a role of NGFR in limiting inflammation for repair of diseased skeletal tissues.

Different clinico-pathological and prognostic features of vulvar, vaginal, and cervical melanomas.

Female genital tract melanoma (FGTM) is a rare and aggressive melanocytic malignancy, and its clinico-pathological and prognostic features at different anatomic sites have not yet been fully described. We retrospectively analyzed and compared the clinico-pathological data and survival outcomes of patients with primary lower genital tract melanoma enrolled between January 2005 and December 2020. We identified 95 patients with FGTM, of whom 46 had vulvar melanomas (VuM), 43 had vaginal melanomas (VaM), and six had cervical melanomas (CM). The clinical characteristics of all 95 cases, including symptoms, single or multiple primary lesions, clinical stage, surgery, and histopathological characteristics of 62 primary untreated cases, including pigmentation, predominant cytology, histological pattern, mitotic figures, and tumor-infiltrating lymphocytes of VuM, VaM, and CM, differed significantly. In comparison, only trend differences in molecular alternations were evident (p = 0.077). Disease-specific survival (DSS) was 30.7% at 5 years (46.5%, 25.6%, and 44.4% for VuM, VaM and CM, respectively). Seventy-one (85.5%) patients experienced FGTM recurrence. The median time to the first recurrence was 11 months, and VaM recurred earlier than VM and CM (16, 6, and 10 months for VuM, VaM, and CM, respectively, p = 0.038). A univariate analysis of 50 cases revealed the negative factors of disease-specific survival (DSS), including the location of the vagina and the presence of ulceration, and the negative factors of recurrence-free survival (RFS), including multiple lesions, the presence of ulceration, and the presence of lymphovascular invasion. Multiple lesions showed a borderline correlation with DSS. A multivariate Cox regression analyses of 50 cases revealed that the presence of ulceration was associated with shorter DSS and RFS (yes vs. no, Hazard Ratio = 2.400 and 2.716, respectively). Vaginal location showed a significant correlation with DSS (Hazard Ratio = 2.750, p = 0.024). In conclusion, vulval, vaginal, and cervical melanomas may differ in terms of their clinico-pathological features and associations with DSS and RFS. Ulceration and vaginal location were significantly associated with shorter DSS, and ulceration was associated with an increased risk of FGTM recurrence.

PD-L1 immunohistochemistry assay optimization to provide more comprehensive pathological information in classic Hodgkin lymphoma.

Overexpression of PD-L1 can be a predictive marker for anti-PD-1 therapeutic efficacy in classic Hodgkin lymphoma (CHL); however, harmonization of different IHC assays remains to be accomplished, and interpretations of PD-L1 immunostaining results remain controversial in CHL. In this study, we sought to optimize the PD-L1 immunohistochemistry (IHC) assay in CHL. All tests were performed on a tumour tissue microarray established from 54 CHL cases. Three IHC antibodies (405.9A11, SP142, 22C3) for detecting PD-L1 expression were compared semi quantitatively with the RNAscope assay (No. 310035, ACD), and the difference in the expression in background immune cells (ICs) between assays and the associations of expression levels with densities of TILs/TAMs were also analysed. 405.9A11 demonstrated best specificity in HRS cells and best sensitivity in ICs. Positive expression of PD-L1 was more frequent in ICs (85.2%) than in HRS cells (48.1%). Different subgroups of background ICs, including tumour-associated macrophages (TAMs), were assessed and scored for CD4, CD8, FOXP3, and CD163 expression. PD-L1 expression on ICs was the factor most associated with the density of TAMs. 405.9A11 provided the most convincing PD-L1 expression results. Pathologists should report PD-L1 expression in a combined manner, including both the status of HRS cells and the percentage of PD-L1-positive ICs.

Different situations of identifying second primary malignant tumors in lymphoma patients with synchronous solid tumors.

BACKGROUND: To our knowledge, the different situations of identifying second primary malignant tumors (SPMTs) in lymphoma patients with synchronous solid tumors remain to be comprehensively investigated. METHODS: We retrospectively collected information pertaining to lymphoma patients with synchronous solid tumors (diagnosed within 6 months) at Peking University Cancer Hospital & Institute between 2009 and 2019. The non-parametric Aalen-Johansen estimator was applied to calculate cumulative incidence function in the competing risk model. Furthermore, propensity score-matched analysis was performed to compare survival differences in lymphoma patients with or without synchronous solid tumors. RESULTS: Thirty-eight patients were enrolled. There were three situations of identifying SPMTs. First, in 15 patients (39.5%), SPMTs were identified before the initiation of any treatment. Among them, priority was given to anti-lymphoma treatment in case of only three patients. Second, in 17 patients (44.7%), SPMTs were unexpectedly detected on surgical specimen assessment; of them, 13 received anti-lymphoma treatment after surgery. Third, in six patients (15.8%), SPMTs were identified after the outset of treatment for the primary tumor; in this population, three of four patients with lymphoma switched toward the treatment plan for SPMTs. The 5-year overall survival was 58.7%. The cumulative incidence function within 5 years was 26.6% for lymphoma and 14.7% for other solid tumors. The early identification of SPMTs was associated with better outcomes (p = 0.048). After balancing the baseline characteristics, no differences in survival were observed between lymphoma patients with and without synchronous solid tumors (p = 0.664). CONCLUSIONS: This is the first study to present the different situations of identifying SPMTs in lymphoma patients with synchronous solid tumors. In only <50% patients, SPMTs were identifiable at baseline. SPMT identification at different situations may make it difficult to choose the optimal therapeutic option, which may consequently impact patient survival.

Pip5k1c Loss in Chondrocytes Causes Spontaneous Osteoarthritic Lesions in Aged Mice.

Osteoarthritis (OA) is the most common degenerative joint disease affecting the older populations globally. Phosphatidylinositol-4-phosphate 5-kinase type-1 gamma (Pip5k1c), a lipid kinase catalyzing the synthesis of phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2), is involved in various cellular processes, such as focal adhesion (FA) formation, cell migration, and cellular signal transduction. However, whether Pip5k1c plays a role in the pathogenesis of OA remains unclear. Here we show that inducible deletion of Pip5k1c in aggrecan-expressing chondrocytes (cKO) causes multiple spontaneous OA-like lesions, including cartilage degradation, surface fissures, subchondral sclerosis, meniscus deformation, synovial hyperplasia, and osteophyte formation in aged (15-month-old) mice, but not in adult (7-month-old) mice. Pip5k1c loss promotes extracellular matrix (ECM) degradation, chondrocyte hypertrophy and apoptosis, and inhibits chondrocyte proliferation in the articular cartilage of aged mice. Pip5k1c loss dramatically downregulates the expressions of several key FA proteins, including activated integrin ß1, talin, and vinculin, and thus impairs the chondrocyte adhesion and spreading on ECM. Collectively, these findings suggest that Pip5k1c expression in chondrocytes plays a critical role in maintaining articular cartilage homeostasis and protecting against age-related OA.

Fibroblast Activation Protein and Glycolysis in Lymphoma Diagnosis: Comparison of 68Ga-FAPI PET/CT and 18F-FDG PET/CT.

Our objective was to compare the diagnostic performance of 68Ga-labeled fibroblast activation protein (FAP) inhibitor (FAPI) and 18F-labeled FDG PET/CT in diagnosing lymphomas and to characterize the influence of FAP and glycolytic markers on tracer uptake by involved lesions. Methods: Participants with different lymphoma subtypes who were prospectively recruited from May 2020 to December 2021 underwent 68Ga-FAPI and 18F-FDG PET/CT. Immunohistochemistry was performed to evaluate FAP, hexokinase 2, and glucose transporter 1 (GLUT1) expression, and the paired-samples t test and Wilcoxon signed-rank test were used to compare parameters. The correlation between the immunochemistry results and tracer uptake was determined by the Spearman rank correlation coefficient. Results: In total, 186 participants (median age, 52 y [interquartile range, 41-64 y]; 95 women) were included. Dual-tracer imaging produced 3 types of imaging profiles. 18F-FDG PET possessed a higher staging accuracy (98.4%) than 68Ga-FAPI PET (86.0%). In 5,980 lymphoma lesions, 18F-FDG PET/CT detected more nodal (4,624 vs. 2,196) and extranodal (1,304 vs. 845) lesions than 68Ga-FAPI PET/CT. Additionally, 52 68Ga-FAPI-positive/18F-FDG-negative lesions and 2,939 68Ga-FAPI-negative/18F-FDG-positive lesions were observed. In many lymphoma subtypes, semiquantitative evaluation revealed no significant differences in SUVmax or target-to-liver ratios between 68Ga-FAPI and 18F-FDG PET/CT (P > 0.05). Interestingly, GLUT1 and hexokinase 2 were overexpressed both in lymphoma cells and in the tumor microenvironment, whereas FAP was expressed only in stromal cells. FAP and GLUT1 expression correlated positively with 68Ga-FAPI SUVmax (r = 0.622, P = 0.001) and 18F-FDG SUVmax (r = 0.835, P < 0.001), respectively. Conclusion: 68Ga-FAPI PET/CT was inferior to 18F-FDG PET/CT in diagnosing lymphomas with low FAP expression. However, the former may supplement the latter and help reveal the molecular profile of lymphomas.