Flow cytometry-assisted analysis of phenotypic maturation markers on an immortalized dendritic cell line.

Dendritic cells (DCs), and especially so conventional type I DCs (cDC1s), are fundamental regulators of anticancer immunity, largely reflecting their superior ability to engulf tumor-derived material and process it for cross-presentation on MHC Class I molecules to CD8+ cytotoxic T lymphocytes (CTLs). Thus, investigating key DC functions including (but not limited to) phagocytic capacity, expression of CTL-activating ligands on the cell surface, and cross-presentation efficacy is an important component of multiple immuno-oncology studies. Unfortunately, DCs are terminally differentiated cells, implying that they cannot be propagated indefinitely in vitro and hence must be generated ad hoc from circulating or bone marrow-derived precursors, which presents several limitations. Here, we propose a simple, cytofluorometric method to quantify phenotypic activation markers including CD80, CD86 and MHC class II molecules on the surface of a conditionally immortalized immature DC line that can be indefinitely propagated in vitro but also driven into maturation at will with a simple change in culture conditions. Upon appropriate scaling and automatization, this approach is compatible with high-throughput screening programs for the discovery of novel DC activators that do not suffer from batch variability and other limitations associated with the generation of fresh DCs.

Generation of transmitochondrial cybrids in cancer cells.

At odds with historical views suggesting that mitochondrial functions are largely dispensable for cancer cells, it is now clear that mitochondria have a major impact on malignant transformation, tumor progression and response to treatment. Mitochondria are indeed critical for neoplastic cells not only as an abundant source of ATP and other metabolic intermediates, but also as gatekeepers of apoptotic cell death and inflammation. Interestingly, while mitochondrial components are mostly encoded by nuclear genes, mitochondria contain a small, circular genome that codes for a few mitochondrial proteins, ribosomal RNAs and transfer RNAs. Here, we describe a straightforward method to generate transmitochondrial cybrids, i.e., cancer cells depleted of their mitochondrial DNA and reconstituted with intact mitochondria from another cellular source. Once established, transmitochondrial cybrids can be stably propagated and are valuable to dissect the specific impact of the mitochondrial genome on cancer cell functions.

Decreased PU.1 expression in mature B cells induces lymphomagenesis.

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of lymphoma, accounting for 30% of non-Hodgkin lymphomas. Although comprehensive analysis of genetic abnormalities has led to the classification of lymphomas, the exact mechanism of lymphomagenesis remains elusive. The Ets family transcription factor, PU.1, encoded by Spi1, is essential for the development of myeloid and lymphoid cells. Our previous research illustrated the tumor suppressor function of PU.1 in classical Hodgkin lymphoma and myeloma cells. In the current study, we found that patients with DLBCL exhibited notably reduced PU.1 expression in their lymphoma cells, particularly in the non-germinal center B-cell-like (GCB) subtype. This observation suggests that downregulation of PU.1 may be implicated in DLBCL tumor growth. To further assess PU.1's role in mature B cells in vivo, we generated conditional Spi1 knockout mice using Cγ1-Cre mice. Remarkably, 13 of the 23 knockout mice (56%) showed splenomegaly, lymphadenopathy, or masses, with some having histologically confirmed B-cell lymphomas. In contrast, no wild-type mice developed B-cell lymphoma. In addition, RNA-seq analysis of lymphoma cells from Cγ1-Cre Spi1F/F mice showed high frequency of each monoclonal CDR3 sequence, indicating that these lymphoma cells were monoclonal tumor cells. When these B lymphoma cells were transplanted into immunodeficient recipient mice, all mice died within 3 weeks. Lentiviral-transduced Spi1 rescued 60% of the recipient mice, suggesting that PU.1 has a tumor suppressor function in vivo. Collectively, PU.1 is a tumor suppressor in mature B cells, and decreased PU.1 results in mature B-cell lymphoma development.

Clinicopathological significance of hyaluronan and hyaluronidase 2 (HYAL2) in breast cancer.

Hyaluronan (HA), as a component of extracellular matrix, has pivotal roles in both physiological and pathological condition. In breast cancer, while high molecular weight HA is produced by hyaluronan synthase, it is degraded by hyaluronidases (hyaluronidase-1 (HYAL1) and hyaluronidase-2 (HYAL2)) into low molecular weight HA (LMW HA), which is considered to have pro-tumorigenic effects in human malignancies. However, HA and HYAL2, the rate-limiting enzyme of HA degradation, have not been comprehensively examined in breast cancer and clinicopathological significance of LMW HA remains to be elucidated in breast cancer. We therefore histochemically localized HA as well as HYAL2 in 116 breast cancer tissues. In addition, we examined size-dependent function of HA on breast cancer cell proliferation and migration using MCF-7 and MDA-MB-231 breast cancer cell lines. HA was localized in both the stroma and breast carcinoma cells, while HYAL2 was predominantly localized in breast carcinoma cells. HA was significantly correlated with cell proliferation and invasion ability as well as increased risk of recurrence especially in HYAL2 positive group. On the other hand, HYAL2 was correlated with breast cancer cell proliferation and increased risk of recurrence. In addition, in vitro analyses revealed that lower molecular weight HA increased sphere forming ability and migration in MCF-7 and MDA-MB-231, whereas higher molecular weight HA inhibited them. It was concluded that HA needs to be degraded by HYAL2 to exert pro-tumorigenic effects and comprehensive HA/HYAL2 status serves as a potent prognostic factor in breast cancer.

Toll-like receptor (TLR) 4 is a potent prognostic factor in prostate cancer associated with proliferation and invasion.

Prostate cancer is one of the most common malignancies in men, and there is a need to explore novel biomarkers or therapeutic targets. Toll-like receptor 4 (TLR4) is expressed not only in antigen-presenting cells but also types of human malignancies, contributing to disease progression, although its clinical significance or functional role in prostate cancer remains unclear. Therefore, we immunolocalized TLR4 in 117 prostate cancer tissues to address its clinicopathological significance. Additionally, we performed in vitro assays to examine the effects of TLR4 on proliferation and migration of prostate cancer cell lines (LNCaP, DU-145 and PC-3). TLR4 immunoreactivity was predominantly detected in the cytoplasm of prostate cancer cells, and it was positively associated with proliferation and invasion abilities, as well as Gleason score. Subsequent in vitro experiments revealed that the inhibition of TLR4 by Sparstolonin B (SsnB) significantly suppressed the proliferation and migration of LNCaP, DU-145 and PC-3 cells. Therefore, we concluded that TLR4 was a potent prognostic factor associated with proliferation and invasion, and it might serve as a therapeutic target in prostate cancer.

Clinicopathological Significance and Prognostic Role of High Mobility Group Box 1 (HMGB1), Toll-Like Receptor (TLR) 2 and TLR4 in Breast Cancer.

High-mobility group box 1 (HMGB1) functions as damage-associated molecular pattern (DAMPs), released into extracellular space during cellular stress. Extracellular HMGB1 act as signal molecules through Toll-like receptor (TLR) 2 or TLR4, exerting diverse functions in both normal cells and malignant cells including breast cancer. However, their comprehensive examination in breast cancer tissues is lacking. Thus, we immunolocalized them in 112 breast cancer tissues, correlating their immunoreactivity with clinicopathological parameters and clinical outcomes to clarify their significance in breast cancer. We demonstrated that nuclear HMGB1 immunoreactivity was correlated with tumor progression and longer disease-free survival. In contrast, TLR2 immunoreactivity was correlated with increased cell proliferation and shorter disease-free survival, dependent on cytoplasmic HMGB1 immunoreactivity. Additionally, TLR4 immunoreactivity correlated with chemoresistance, regardless of cytoplasmic HMGB1 immunoreactivity. It was therefore considered that TLR2 collaboratively contributed to breast cancer progression with HMGB1-DAMPs to become a worse prognostic factor. Meanwhile, TLR4 served as a worse prognostic factor associated with chemoresistance, irrespective of HMGB1.

Efficacy and Safety of Esaxerenone in Hypertensive Patients with Diabetes Mellitus Undergoing Treatment with Sodium-Glucose Cotransporter 2 Inhibitors (EAGLE-DH).

INTRODUCTION: The EAGLE-DH study assessed the efficacy and safety of esaxerenone in hypertensive patients with diabetes mellitus receiving sodium-glucose cotransporter 2 (SGLT2) inhibitors. METHODS: In this multicenter, open-label, prospective, interventional study, esaxerenone was started at 1.25 or 2.5 mg/day and could be gradually increased to 5 mg/day on the basis of blood pressure (BP) and serum potassium levels. Oral hypoglycemic or antihypertensive medications prior to obtaining consent was continued. Data were evaluated in the total population and creatinine-based estimated glomerular filtration rate (eGFR) subcohorts (eGFR ≥ 60 mL/min/1.73 m2 [G1-G2 subcohort] and 30 to < 60 mL/min/1.73 m2 [G3 subcohort]). RESULTS: In total, 93 patients were evaluated (G1-G2, n = 49; G3, n = 44). Morning home systolic/diastolic BP values (SBP/DBP) were significantly reduced from baseline to week 12 (- 11.8 ± 10.8/- 5.1 ± 6.3 mmHg, both P < 0.001) and week 24 (- 12.9 ± 10.5/- 5.7 ± 6.3 mmHg, both P < 0.001). Similar results were observed in both eGFR subcohorts. The urinary albumin-to-creatinine ratio significantly decreased from baseline to week 24 in the total population (geometric percentage change, - 49.1%, P < 0.001) and in both eGFR subcohorts. The incidences of treatment-emergent adverse events (TEAEs) and drug-related TEAEs were 45.2% and 12.9%, respectively; most were mild or moderate. Serum potassium levels increased over the first 2 weeks of esaxerenone treatment, gradually decreased by week 12, and remained constant to week 24. One patient in the G1-G2 subcohort had serum potassium levels ≥ 5.5 mEq/L. No patients had serum potassium ≥ 6.0 mEq/L. CONCLUSION: Esaxerenone effectively lowered BP, was safe, and showed renoprotective effects in hypertensive patients with diabetes mellitus receiving treatment with SGLT2 inhibitors. Esaxerenone and SGLT2 inhibitors did not interfere with either drug's efficacy and may reduce the frequency of serum potassium elevations, suggesting they are a compatible combination. CLINICAL TRIAL REGISTRATION: jRCTs031200273.

Interleukin (IL)-17A in triple-negative breast cancer: a potent prognostic factor associated with intratumoral neutrophil infiltration.

BACKGROUND: Triple-negative breast cancer (TNBC) is characterized as highly immunogenic and lacks specific targeted therapies. Interleukin 17A (IL-17A) is a controversial cytokine and is known to have anti-tumor and pro-tumor roles depending on the tumor microenvironment. In addition, IL-17A has been recently implicated in the recruitments of neutrophil into tumor tissues. Although IL-17A is considered tumor-promoting in breast cancer, its significance in the possible regulation of neutrophil infiltration in TNBC is not clearly defined. MATERIALS AND METHODS: We immunolocalized IL-17A, CD66b (neutrophil marker), and chemokine (C-X-C motif) ligand 1 (CXCL1, neutrophil chemoattractant) in 108 TNBC specimens and assessed their correlation among each other. The correlation between these markers and clinicopathological parameters was also assessed. We subsequently performed in vitro study to address the possible regulation of CXCL1 by IL-17A using TNBC cell lines, MDA-MB-231 and HCC-38. RESULTS: It was revealed that IL-17A correlated significantly with CXCL1 and CD66b, also CD66b with CXCL1. Furthermore, IL-17A was significantly associated with shorter disease-free and overall survival, especially in a high density CD66b group of patients. In vitro results revealed that IL-17A upregulated CXCL1 mRNA expression in a dose and time dependent manner, and this induction was significantly suppressed by an Akt inhibitor. CONCLUSION: IL-17A was considered to contribute to neutrophil infiltration by inducing CXCL1 in TNBC tissues and educating neutrophils to promote tumor progression. IL-17A might therefore serve as a potent prognostic factor in TNBC.

Kallikrein-Related Peptidase 12 (KLK12) in Breast Cancer as a Favorable Prognostic Marker.

Kallikrein-related peptides (KLKs) form an evolutionally conserved subgroup of secreted serine proteases that consists of 15 members (KLK1-15). Previous studies have shown that KLKs regulate diverse biological processes, but the clinical significance of KLKs remains largely unclear in human breast cancers. We examined the expression profile of 15 KLK genes in breast carcinomas using microarray data. Next, we immunolocalized KLK12 in 140 breast carcinomas and evaluated its clinical significance. Subsequently, we examined the effects of KLK12 on proliferation and migration in breast cancer cell lines. From microarray analyses, it turned out that KLK12 was the most strongly associated with low-grade malignancy in breast carcinomas among the 15 KLK members. Immunohistochemical KLK12 status was positively associated with ER and PR status, while it was inversely associated with stage, pathological T factor, lymph node metastasis, and distant metastasis. Prognostic analyses demonstrated that KLK12 was a favorable prognostic factor for both disease-free and breast cancer-specific survival of the patients. Furthermore, the knockdown of KLK12 significantly increased cell proliferation activity and cell migration of breast cancer cells. These results suggest that KLK12 has antitumorigenic effects associated with proliferation and migration and immunohistochemical KLK12 status as a potent favorable prognostic factor in breast carcinoma patients.

The Pro-Tumorigenic Role of Chemotherapy-Induced Extracellular HSP70 from Breast Cancer Cells via Intratumoral Macrophages.

Tumor-associated macrophages (TAMs) contribute to tumor progression and chemoresistance; it is therefore important to clarify the altered functions of macrophages following chemotherapy. While extracellular heat shock protein (HSP) 70 is associated with therapeutic resistance, the effects of HSP70 on TAMs remain largely unknown. Here, we conducted in vitro experiments and immunohistochemistry in 116 breast carcinoma specimens to determine whether the secretion of HSP70 from breast cancer cells following chemotherapy affects macrophage function. It was revealed that the interaction of epirubicin (EPI)-exposed breast cancer cells with macrophages enhanced tumor progression, and EPI promoted the secretion of extracellular HSP70 from breast cancer cells. The expression of pro-tumorigenic macrophage marker CD163 was decreased in macrophages treated with a conditioned medium (CM) from HSP70-silenced breast cancer cells. Breast cancer cells treated with CM from HSP70-silenced breast cancer cells showed decreased expression of transforming growth factor (TGF)-ß, and the pro-tumorigenic effects of macrophages were impaired when TGF-ß signaling was inhibited. Immunohistochemistry demonstrated that HSP70 served as a poor prognostic factor in conjunction with macrophage infiltration. It was therefore concluded that extracellular HSP70 levels increased following chemotherapy and enhanced the pro-tumorigenic effects of TAMs, either directly or indirectly, by regulating TGF-ß expression in breast cancer cells.

Cellular senescence in the response of HR+ breast cancer to radiotherapy and CDK4/6 inhibitors.

BACKGROUND: Preclinical evidence from us and others demonstrates that the anticancer effects of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors can be enhanced with focal radiation therapy (RT), but only when RT is delivered prior to (rather than after) CDK4/6 inhibition. Depending on tumor model, cellular senescence (an irreversible proliferative arrest that is associated with the secretion of numerous bioactive factors) has been attributed beneficial or detrimental effects on response to treatment. As both RT and CDK4/6 inhibitors elicit cellular senescence, we hypothesized that a differential accumulation of senescent cells in the tumor microenvironment could explain such an observation, i.e., the inferiority of CDK4/6 inhibition with palbociclib (P) followed by RT (P→RT) as compared to RT followed by palbociclib (RT→P). METHODS: The impact of cellular senescence on the interaction between RT and P was assessed by harnessing female INK-ATTAC mice, which express a dimerizable form of caspase 8 (CASP8) under the promoter of cyclin dependent kinase inhibitor 2A (Cdkn2a, coding for p16Ink4), as host for endogenous mammary tumors induced by the subcutaneous implantation of medroxyprogesterone acetate (MPA, M) pellets combined with the subsequent oral administration of 7,12-dimethylbenz[a]anthracene (DMBA, D). This endogenous mouse model of HR+ mammary carcinogenesis recapitulates key immunobiological aspects of human HR+ breast cancer. Mice bearing M/D-driven tumors were allocated to RT, P or their combination in the optional presence of the CASP8 dimerizer AP20187, and monitored for tumor growth, progression-free survival and overall survival. In parallel, induction of senescence in vitro, in cultured human mammary hormone receptor (HR)+ adenocarcinoma MCF7 cells, triple negative breast carcinoma MDA-MB-231 cells and mouse HR+ mammary carcinoma TS/A cells treated with RT, P or their combination, was determined by colorimetric assessment of senescence-associated ß-galactosidase activity after 3 or 7 days of treatment. RESULTS: In vivo depletion of p16Ink4-expressing (senescent) cells ameliorated the efficacy of P→RT (but not that of RT→P) in the M/D-driven model of HR+ mammary carcinogenesis. Accordingly, P→RT induced higher levels of cellular senescence than R→TP in cultured human and mouse breast cancer cell lines. CONCLUSIONS: Pending validation in other experimental systems, these findings suggest that a program of cellular senescence in malignant cells may explain (at least partially) the inferiority of P→RT versus RT→P in preclinical models of HR+ breast cancer.

Quantitative assessment of mitophagy in irradiated cancer cells.

Mitophagy is a finely regulated mechanism through which eukaryotic cells selectively dispose of supernumerary, permeabilized or otherwise damaged mitochondria through lysosomal degradation. Dysfunctional mitochondria are prone to release potentially cytotoxic factors including reactive oxygen species (ROS) and caspase activators, such as cytochrome c, somatic (CYCS). Thus, proficient mitophagic responses mediate prominent cytoprotective functions. Moreover, the rapid degradation of permeabilized mitochondria limits the release of mitochondrial components that may drive inflammatory reactions, such as mitochondrial DNA (mtDNA) and transcription factor A, mitochondrial (TFAM), implying that mitophagy also mediates potent anti-inflammatory effects. Here, we detail a simple, flow cytometry-assisted protocol for the specific measurement of mitophagic responses as driven by radiation therapy (RT) in mouse hormone receptor (HR)+ mammary carcinoma TS/A cells. With some variations, this method - which relies on the mitochondria-restricted expression of a fluorescent reporter that is sensitive to pH and hence changes excitation wavelength within lysosomes (mt-mKeima) - can be adapted to a variety of human and mouse cancer cell lines and/or straightforwardly implemented on fluorescence microscopy platforms.

A Case of Paraneoplastic Neurological Syndrome Associated with Breast Cancer Detected while Searching for the Cause of Involuntary Movement.

Our case involved a 66-year-old woman who noticed progressive asymmetric involuntary movement, difficulty speaking, and difficulty swallowing. The patient fractured her femur due to a lower extremity involuntary movement while walking. During the course of her treatment for the fracture, her neurological symptoms worsened. Approximately 2 months after becoming aware of her symptoms, she visited our clinic for evaluation of difficulty with unassisted walking and weight loss due to dysphagia. To identify the cause of her neurological symptoms, hematological examination, brain magnetic resonance imaging, single-photon emission computed tomography for cerebral blood flow, electroencephalography, and a somatosensory evoked potential test were conducted. Although the cause of her neurological symptoms could not be determined, computed tomography revealed the presence of breast cancer, which led us to suspect paraneoplastic neurological syndrome (PNS). After breast cancer treatment, her neurological symptoms improved simultaneously. Therefore, the patient was retrospectively diagnosed with PNS. We report a case of PNS whose neurological symptoms followed a subacute course and were relieved after breast cancer treatment.

Cytofluorometric assessment of cell cycle progression in irradiated cells.

Radiation therapy (RT) is well known for its capacity to mediate cytostatic and cytotoxic effects upon the accumulation of unrepaired damage to macromolecules, notably DNA. The ability of ionizing radiation to prevent malignant cells from replicating and to cause their demise is indeed an integral component of the anticancer activity of RT. Neoplastic cells are generally more sensitive to the cytostatic and cytotoxic effects of RT than their healthy counterparts as they exhibit increased proliferative rate and limited capacity for DNA repair. This provides a rather comfortable therapeutic window for clinical RT usage, especially with the development of novel, technologically superior RT modalities that minimize the exposure of normal tissues. Thus, while accumulating evidence indicates that cancer control by RT also involves the activation of tumor-targeting immune responses, assessing cell cycle progression in irradiated cells remains a central approach for investigating radiosensitivity in preclinical tumor models. Here, we detail a simple, flow cytometry-assisted method to simultaneously assess cell cycle distribution and active DNA replication in cultured estrogen receptor (ER)+ breast cancer MCF7 cells. With minimal variations, the same technique can be straightforwardly implemented to a large panel of human and mouse cancer cell lines.

Quantification of cytosolic DNA species by immunofluorescence microscopy and automated image analysis.

When employed according to specific doses and fractionation schedules, radiation therapy (RT) elicits potent tumor-targeting immune responses that rely on the secretion of type I interferon (IFN) by irradiated cancer cells. Most often, this is initiated by the ability of RT to promote the cytosolic accumulation of double-stranded DNA (dsDNA) molecules, which are detected by cyclic GMP-AMP synthase (CGAS) to engage the stimulator of interferon response cGAMP interactor 1 (STING1)-dependent transactivation of type I IFN-coding genes via interferon regulatory factor 3 (IRF3). Here, we describe a simple protocol for the quantification of cytosolic dsDNA species by immunofluorescence microscopy coupled to automated image analysis, as enabled by precise sample processing conditions that permeabilize plasma-but not nuclear or inner mitochondrial-membranes. As compared to subcellular fractionation-based techniques, this approach is compatible with assessments in individual cells aimed at gauging inter-cellular heterogeneity, as well as subcellular tests including co-localization studies.

RT-PCR-assisted quantification of type I IFN responses in irradiated cancer cells.

It is now clear that radiation therapy (RT) can be delivered in doses and according to fractionation schedules that actively elicit immunostimulatory effects. While such effects are often sufficient to drive potent anticancer immunity culminating with systemic disease eradication, the immunostimulatory activity of RT stands out as a promising combinatorial partner for bona fide immunotherapeutics including immune checkpoint inhibitors (ICIs). Accumulating preclinical and clinical evidence indicates that the secretion of type I interferon (IFN) by irradiated cancer cells is a sine qua non for RT to initiate ICI-actionable tumor-targeting immune responses. Here, we detail a simple protocol to quantitatively assess type I IFN responses in irradiated mouse hormone receptor (HR)+ TS/A cells by RT-PCR. With minimal variations, the same technique can be straightforwardly adapted to quantify type I IFN-associated transcriptional responses in a variety of human and mouse cancer cells maintained in vitro.

Cytofluorometric assessment of acute cell death responses driven by radiation therapy.

Radiation therapy (RT) is well known for its capacity to mediate cytostatic and cytotoxic effects on malignant cells, largely reflecting the ability of ionizing radiation to cause direct and indirect damage to macromolecules including DNA and lipids. While low-dose RT generally causes limited cytotoxicity in an acute manner (as it imposes insufficient cellular damage to compromise homeostasis, or instead induces the delayed demise of cells that fail to complete mitosis successfully), high RT doses can mediate an acute wave of cell death that begins to manifest shortly (24-72h) after irradiation. Here, we provide two straightforward techniques to assess the acute cytotoxic effects of RT by the flow cytometry-assisted quantification of plasma membrane permeabilization (PMP, a late-stage manifestation of cell death) and either mitochondrial outer membrane permeabilization (MOMP) or phosphatidylserine (PS) externalization (two early-stage signs of cell death) in mouse mammary adenocarcinoma TS/A cells. With minor variations, the same protocols can be straightforwardly adapted to measure acute cell death responses as elicited by RT in a large panel of human and mouse cancer cells lines of different histological derivation.