Near-infrared photoimmunotherapy targeting PD-L1: Improved efficacy by preconditioning the tumor microenvironment.

Near-infrared photoimmunotherapy (NIR-PIT) is a new type of cancer therapy that employs antibody-IRDye700DX conjugates (AbPCs) and near-infrared (NIR) light at a wavelength of 689 nm, the excitation wavelength of IR700. Administered intravenously, injected AbPCs bind specifically to cells expressing the target antigen, whereupon NIR light exposure causes rapid, selective killing. This process induces an anticancer T cell response, leading to sustained anticancer host immune response. Programmed cell death ligand-1 (PD-L1) is a major inhibitory immune checkpoint molecule expressed in various cancers. In this study, we first assessed the efficacy of PD-L1-targeted NIR-PIT (αPD-L1-PIT) in immune-competent tumor mouse models. αPD-L1-PIT showed a significant therapeutic effect on the tumor models with high PD-L1 expression. Furthermore, αPD-L1-PIT induced an abscopal effect on distant tumors and long-term immunological memory. In contrast, αPD-L1-PIT was not as effective for tumor models with low PD-L1 expression. To improve the efficacy of PD-L1-targeted NIR-PIT, PEGylated interferon-gamma (IFNγ) was administered with αPD-L1-PIT. The combination therapy improved the treatment efficacy by increasing PD-L1 expression leading to more efficient cell killing by αPD-L1-PIT. Furthermore, the PEGylated IFNγ led to a CD8+ T cell-dominant tumor microenvironment (TME) with an enhanced anticancer T cell response after αPD-L1-PIT. As a result, even so-called cold tumors exhibited complete responses after αPD-L1-PIT. Thus, combination therapy of PEGylated IFNγ and PD-L1-targeted NIR-PIT has the potential to be an important future strategy for cancer immunotherapy.

REV7 is involved in outcomes of platinum-based chemotherapy in pancreatic cancer by controlling the DNA damage response.

REV7 is a multifunctional protein implicated in various biological processes, including DNA damage response. REV7 expression in human cancer cells affects their sensitivity to DNA-damaging agents. In the present study, we investigated the significance of REV7 in pancreatic ductal adenocarcinoma (PDAC). REV7 expression was immunohistochemically examined in 92 resected PDAC specimens and 60 endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) specimens of unresectable PDAC treated with platinum-based chemotherapy, and its association with clinicopathologic features was analyzed. Although REV7 expression was not significantly associated with the progression of primary tumors (T-factor and Stage) in either resected or unresectable PDAC, decreased levels of REV7 expression in EUS-FNAB specimens of unresectable PDAC were significantly associated with better outcomes of platinum-based chemotherapy and a favorable prognosis. REV7-deficient PDAC cell lines showed suppressed cell growth and enhanced sensitivity to cisplatin in vitro. Tumor-bearing mice generated using REV7-deficient PDAC cell lines also showed enhanced sensitivity to cisplatin in vivo. RNA sequencing analysis using WT and REV7-deficient PDAC cell lines revealed that REV7 inactivation promoted the downregulation of genes involved in the DNA repair and the upregulation of genes involved in apoptosis. Our results indicate that decreased expression of REV7 is associated with better outcomes of platinum-based chemotherapy in PDAC by suppressing the DNA damage response. It is also suggested that REV7 is a useful biomarker for predicting the outcome of platinum-based chemotherapy and the prognosis of unresectable PDAC and is a potential target for PDAC treatment.

Fibroblast activation protein-targeted near-infrared photoimmunotherapy depletes immunosuppressive cancer-associated fibroblasts and remodels local tumor immunity.

BACKGROUND: Cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) play a critical role in tumor immunosuppression. However, targeted depletion of CAFs is difficult due to their diverse cells of origin and the resulting lack of specific surface markers. Near-infrared photoimmunotherapy (NIR-PIT) is a novel cancer treatment that leads to rapid cell membrane damage. METHODS: In this study, we used anti-mouse fibroblast activation protein (FAP) antibody to target FAP+ CAFs (FAP-targeted NIR-PIT) and investigated whether this therapy could suppress tumor progression and improve tumor immunity. RESULTS: FAP-targeted NIR-PIT induced specific cell death in CAFs without damaging adjacent normal cells. Furthermore, FAP-targeted NIR-PIT treated mice showed significant tumor regression in the CAF-rich tumor model accompanied by an increase in CD8+ tumor infiltrating lymphocytes (TILs). Moreover, treated tumors showed increased levels of IFN-γ, TNF-α, and IL-2 in CD8+ TILs compared with non-treated tumors, suggesting enhanced antitumor immunity. CONCLUSIONS: Cancers with FAP-positive CAFs in their TME grow rapidly and FAP-targeted NIR-PIT not only suppresses their growth but improves tumor immunosuppression. Thus, FAP-targeted NIR-PIT is a potential therapeutic strategy for selectively targeting the TME of CAF+ tumors.

Decline in the Conception Rate of Wild Japanese Monkeys after the Fukushima Daiichi Nuclear Power Plant Accident.

We examined the conception rate of wild Japanese monkeys (Macaca fuscata) in Fukushima City that were exposed to radiation as a result of the Fukushima Daiichi Nuclear Power Plant accident in March 2011. The conception rate in the year of delivery from 2009 to 2022 was estimated by dissecting individuals that were euthanized by the government for population control as a countermeasure against crop damage. To evaluate the effects of exposure, the cumulative exposure dose for each individual was calculated using the concentration of radiocesium deposited in the soil at the capture site and the concentration of radiocesium in muscle estimated from the aggregated transfer factor. There were no significant differences in conception rates across all age classes over time. In terms of conception rates by age class, there was a significant decrease post-exposure compared with pre-exposure in the age class ≥ 8 years, but no significant differences in the age class 5-7 years. The non-ovulation rate did not significantly differ between the pre- and post-exposure periods for any age class. Body fat index, which can affect fertility, was compared between the pre- and post-exposure periods, and no significant differences were found in either age class. In contrast, the median total cumulative exposure (cumulative internal exposure + cumulative external exposure) was significantly higher in the age class ≥ 8 years compared with the age class 5-7 years. These results suggest that the total cumulative exposure dose may be one of the reasons for the lower conception rate in the post-exposure period among the age class ≥ 8 years.

Near-infrared photoimmunotherapy in the models of hepatocellular carcinomas using cetuximab-IR700.

Epidermal growth factor receptor (EGFR) has emerged as an important therapeutic target in many cancers, and overexpression of EGFR is frequently observed in hepatocellular carcinomas (HCCs). Near-infrared photoimmunotherapy (NIR-PIT) is a new anticancer treatment that selectively damages the cell membrane of cancer cells after NIR light-induced photochemical reaction of IR700, which is bound to a targeting antibody on the cell membrane. NIR-PIT using cetuximab-IR700 has already been approved in Japan, is under review by the US Food and Drug Administration (FDA) for advanced head and neck cancers, and its safety has been established. However, EGFR has not been investigated as a target in NIR-PIT in HCCs. Here, we investigate the application of NIR-PIT using cetuximab-IR700 to HCCs using xenograft mouse models of EGFR-expressing HCC cell lines, Hep3B, HuH-7, and SNU-449. In vitro NIR-PIT using EGFR-targeted cetuximab-IR700 killed cells in a NIR light dose-dependent manner. In vivo NIR-PIT resulted in a delayed growth compared with untreated controls. In addition, in vivo NIR-PIT in both models showed histological signs of cancer cell damage, such as cytoplasmic vacuolation and nuclear dysmorphism. A significant decrease in Ki-67 positivity was also observed after NIR-PIT, indicating decreased cancer cell proliferation. This study suggests that NIR-PIT using cetuximab-IR700 has potential for the treatment of EGFR-expressing HCCs.

Identification of the promoter region regulating the transcription of the REV7 gene.

REV7 is involved in various biological processes including DNA repair and mutagenesis, cell cycle regulation, gene transcription, and carcinogenesis. REV7 is highly expressed in adult testicular germ cells as well as several malignant tumors. REV7 expression levels are associated with prognosis in several human cancers, however, the mechanism of REV7 transcriptional regulation has not been elucidated. In this study, we characterized the promoter region of the REV7 gene. A luciferase reporter assay using the human germ cell tumor cell line NEC8 was utilized to examine the upstream genomic region of REV7 for transcriptional activity, and two transcriptional activation regions were identified. We determined a small genomic region important for transcriptional activation using site-directed mutagenesis; this region is shared by several putative binding motifs for transcription factors, including the cAMP-responsive element modulator (CREM), cAMP-response element binding protein (CREB), and B-lymphocyte-induced maturation protein-1 (BLIMP-1). Exogenous CREM and CREB expression had no effect on the transcriptional activity in NEC8 cells or the human embryonic kidney cell line HEK293T. In contrast, exogenous BLIMP-1 expression increased luciferase reporter activity in HEK293T cells but unexpectedly decreased activity in NEC8 cells. Chromatin immunoprecipitation analysis demonstrated that BLIMP-1 binds to the genomic region near the binding motif in the REV7 promoter. Additionally, BLIMP-1 overexpression promoted endogenous REV7 expression in HEK293T cells. These findings suggest that BLIMP-1 may be a putative transcriptional regulator of REV7 in mammalian cells.

Overcoming cancer-associated fibroblast-induced immunosuppression by anti-interleukin-6 receptor antibody.

Cancer-associated fibroblasts (CAFs) are a critical component of the tumor microenvironment and play a central role in tumor progression. Previously, we reported that CAFs might induce tumor immunosuppression via interleukin-6 (IL-6) and promote tumor progression by blocking local IL-6 in the tumor microenvironment with neutralizing antibody. Here, we explore whether an anti-IL-6 receptor antibody could be used as systemic therapy to treat cancer, and further investigate the mechanisms by which IL-6 induces tumor immunosuppression. In clinical samples, IL-6 expression was significantly correlated with α-smooth muscle actin expression, and high IL-6 cases showed tumor immunosuppression. Multivariate analysis showed that IL-6 expression was an independent prognostic factor. In vitro, IL-6 contributed to cell proliferation and differentiation into CAFs. Moreover, IL-6 increased hypoxia-inducible factor 1α (HIF1α) expression and induced tumor immunosuppression by enhancing glucose uptake by cancer cells and competing for glucose with immune cells. MR16-1, a rodent analog of anti-IL-6 receptor antibody, overcame CAF-induced immunosuppression and suppressed tumor progression in immunocompetent murine cancer models by regulating HIF1α activation in vivo. The anti-IL-6 receptor antibody could be systemically employed to overcome tumor immunosuppression and improve patient survival with various cancers. Furthermore, the tumor immunosuppression was suggested to be induced by IL-6 via HIF1α activation.

PD-L1-expressing cancer-associated fibroblasts induce tumor immunosuppression and contribute to poor clinical outcome in esophageal cancer.

The programmed cell death 1 protein (PD-1)/programmed cell death ligand 1 (PD-L1) axis plays a crucial role in tumor immunosuppression, while the cancer-associated fibroblasts (CAFs) have various tumor-promoting functions. To determine the advantage of immunotherapy, the relationship between the cancer cells and the CAFs was evaluated in terms of the PD-1/PD-L1 axis. Overall, 140 cases of esophageal cancer underwent an immunohistochemical analysis of the PD-L1 expression and its association with the expression of the α smooth muscle actin, fibroblast activation protein, CD8, and forkhead box P3 (FoxP3) positive cells. The relationship between the cancer cells and the CAFs was evaluated in vitro, and the effect of the anti-PD-L1 antibody was evaluated using a syngeneic mouse model. A survival analysis showed that the PD-L1+ CAF group had worse survival than the PD-L1- group. In vitro and in vivo, direct interaction between the cancer cells and the CAFs showed a mutually upregulated PD-L1 expression. In vivo, the anti-PD-L1 antibody increased the number of dead CAFs and cancer cells, resulting in increased CD8+ T cells and decreased FoxP3+ regulatory T cells. We demonstrated that the PD-L1-expressing CAFs lead to poor outcomes in patients with esophageal cancer. The cancer cells and the CAFs mutually enhanced the PD-L1 expression and induced tumor immunosuppression. Therefore, the PD-L1-expressing CAFs may be good targets for cancer therapy, inhibiting tumor progression and improving host tumor immunity.

Treatment satisfaction with molidustat in CKD-related anemia in non-dialysis patients: a post-hoc analysis of two clinical trials.

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) are the standard treatment for patients with renal anemia to increase hemoglobin (Hb) levels and reduce the need for blood transfusions. However, treatments targeting high Hb levels require high doses of ESAs administered intravenously, which is associated with an elevated risk of adverse cardiovascular events. Furthermore, there have been some problems such as hemoglobin variability and low achievement of target hemoglobin due to the shorter half-lives of ESAs. Consequently, erythropoietin-promoting medications, such as hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors, have been developed. This study aimed to evaluate changes in the Treatment Satisfaction Questionnaire for Medicine version II (TSQM-II) domain scores relative to baseline in each trial, to assess patient satisfaction with molidustat versus darbepoetin alfa. METHODS: This post-hoc analysis of two clinical trials compared treatment satisfaction with an HIF-PH inhibitor, molidustat, versus a standard ESA, darbepoetin alfa, as part of therapy in patients with non-dialysis chronic kidney disease (CKD) and renal anemia. RESULTS: Exploratory outcome data using the TSQM-II showed that both arms in both trials had enhanced treatment satisfaction over the course of the study period, as well as improvements in most TSQM-II domains at week 24 of treatment. Molidustat was associated with convenience domain scores at multiple time points depending on the trial. More patients were highly satisfied with the convenience of molidustat than that of darbepoetin alfa. Patients treated with molidustat had increased global satisfaction domain scores compared with those treated with darbepoetin alfa; however, the differences in global satisfaction domain scores were not significant. CONCLUSION: These patient-reported satisfaction outcomes support the use of molidustat as a patient-centered treatment option for CKD-related anemia. REGISTRATION OF CLINICAL TRIALS: ClinicalTrials.gov Identifier: NCT03350321 (November 22, 2017). CLINICALTRIALS: gov Identifier: NCT03350347 (November 22, 2017).

[Novel Therapy Targeting the Cancer Microenvironment Using Near-Infrared Photoimmunotherapy Leading to Tumor Immune Activation].

Near-infrared photoimmunotherapy(NIR-PIT)is a novel cancer treatment modality that employs antibody-IRDye700DX (IR700)conjugates. Recently, the clinical application of NIR-PIT has received approval in Japan for patients with inoperable head and neck cancer, specifically targeting the human epidermal growth factor receptor(hEGFR). Furthermore, NIR-PIT extends beyond the scope of tumor antigens and can be employed to eliminate specific host cells that contribute to the creation of immune-permissive environments supporting tumor growth. One of the distinguishing features of NIR-PIT is its ability to selectively eliminate various cell types within the tumor microenvironment(TME)by specifically targeting distinct antigens. By employing podoplanin(PDPN)-targeted NIR-PIT, PDPN-expressing fibroblasts were selectively eradicated, resulting in the suppression of tumor progression and a notable extension of overall survival. Additionally, we investigated the efficacy of depleting myeloid-derived suppressor cells(MDSCs)using NIR-PIT. This approach led to the selective elimination of MDSCs within tumors, and remarkable abscopal effects were observed in bilateral tumor models. Hence, NIR-PIT holds immense promise for the treatment of diverse cancer types by precisely targeting tumor cells, fibroblasts, and immune cells.

Cyanine Phototruncation Enables Spatiotemporal Cell Labeling.

Photoconvertible tracking strategies assess the dynamic migration of cell populations. Here we develop phototruncation-assisted cell tracking (PACT) and apply it to evaluate the migration of immune cells into tumor-draining lymphatics. This method is enabled by a recently discovered cyanine photoconversion reaction that leads to the two-carbon truncation and consequent blue-shift of these commonly used probes. By examining substituent effects on the heptamethine cyanine chromophore, we find that introduction of a single methoxy group increases the yield of the phototruncation reaction in neutral buffer by almost 8-fold. When converted to a membrane-bound cell-tracking variant, this probe can be applied in a series of in vitro and in vivo experiments. These include quantitative, time-dependent measurements of the migration of immune cells from tumors to tumor-draining lymph nodes. Unlike previously reported cellular photoconversion approaches, this method does not require genetic engineering and uses near-infrared (NIR) wavelengths. Overall, PACT provides a straightforward approach to label cell populations with spatiotemporal control.

Intercellular adhesion molecule-1-targeted near-infrared photoimmunotherapy of triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and conventional chemotherapy and molecular-targeted therapies show limited efficacy. Near-infrared photoimmunotherapy (NIR-PIT) is a new anticancer treatment that selectively damages the cell membrane of cancer cells based on NIR light-induced photochemical reactions of the antibody (Ab)-photoabsorber (IRDye700Dx) conjugate and the cell membrane. TNBC is known to express several adhesion molecules on the cell surface providing a potential new target for therapy. Here, we investigated the therapeutic efficacy of intercellular adhesion molecule-1 (ICAM-1)-targeted NIR-PIT using xenograft mouse models subcutaneously inoculated with two human ICAM-1-expressing TNBC cell lines, MDAMB468-luc and MDAMB231 cells. In vitro ICAM-1-targeted NIR-PIT damaged both cell types in a NIR light dose-dependent manner. In vivo ICAM-1-targeted NIR-PIT in both models showed early histological signs of cancer cell damage, such as cytoplasmic vacuolation. Even among the cancer cells that appeared to be morphologically intact within 2 h post treatment, abnormal distribution of the actin cytoskeleton and a significant decrease in Ki-67 positivity were observed, indicating widespread cellular injury reflected in cytoplasmic degeneration. Such damage to cancer cells by NIR-PIT significantly inhibited subsequent tumor growth and improved survival. This study suggests that ICAM-1-targeted NIR-PIT could have potential clinical application in the treatment of TNBC.

Opening up new VISTAs: V-domain immunoglobulin suppressor of T cell activation (VISTA) targeted near-infrared photoimmunotherapy (NIR-PIT) for enhancing host immunity against cancers.

V-domain immunoglobulin suppressor of T cell activation (VISTA) is an inhibitory immune checkpoint molecule that is broadly expressed on lymphoid and myeloid cells, including regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Near-infrared photoimmunotherapy (NIR-PIT) is a cancer treatment that utilizes an antibody-photoabsorber (IRDye 700DX NHS ester) conjugate to selectively kill target cells after the local application of NIR light. Depletion of VISTA-expressing cells in the tumor microenvironment (TME) using NIR-PIT could enhance anti-tumor immune responses by removing immune suppressive cells. The purpose of this study was to evaluate the anti-tumor efficacy of VISTA-targeted NIR-PIT using two murine tumor models, MC38-luc and LL2-luc. VISTA was expressed on T cells including Tregs and MDSCs in the TME of these tumors. In contrast, CD45 - cells, including cancer cells, did not express VISTA. VISTA-targeted NIR-PIT depleted VISTA-expressing cells ex vivo. In vivo VISTA-targeted NIR-PIT inhibited tumor progression and prolonged survival in both models. After VISTA-targeted NIR-PIT, augmented CD8 + T cell and dendritic cell activation were observed in regional lymph nodes. In conclusion, VISTA-targeted NIR-PIT can effectively treat tumors by decreasing VISTA-expressing immune suppressor cells in the TME. Local depletion of VISTA-expressing cells in the tumor bed using NIR-PIT is a promising new cancer immunotherapy for treating various types of tumors.

Selection of antibody and light exposure regimens alters therapeutic effects of EGFR-targeted near-infrared photoimmunotherapy.

Near-infrared photoimmunotherapy (NIR-PIT) is a cell-specific cancer therapy that uses an antibody-photoabsorber (IRDye700DX, IR700) conjugate (APC) and NIR light. Intravenously injected APC binds the target cells, and subsequent NIR light exposure induces immunogenic cell death only in targeted cells. Panitumumab and cetuximab are antibodies that target human epidermal growth factor receptor (hEGFR) and are suitable for NIR-PIT. In athymic nude mouse models, panitumumab-based NIR-PIT showed superior therapeutic efficacy compared to cetuximab-based NIR-PIT because of the longer half-life of panitumumab-IR700 (pan-IR700) compared with cetuximab-IR700 (cet-IR700). Two light exposures on two consecutive days have also been shown to induce superior effects compared to a single light exposure in the athymic nude mouse model. However, the optimal regimen has not been assessed in immunocompetent mice. In this study, we compared panitumumab and cetuximab in APCs for NIR-PIT, and single and double light exposures using a newly established hEGFR-expressing cancer cell line derived from immunocompetent C57BL/6 mice (mEERL-hEGFR cell line). Fluorescence imaging showed that the decline of pan-IR700 was slower than cet-IR700 confirming a longer clearance time. Among all the combinations tested, mice receiving pan-IR700 and double light exposure showed the greatest tumor growth inhibition. This group was also shown to activate CD8+ T lymphocytes in lymph nodes and accumulate CD8+ T lymphocytes to a greater extent within the tumor compared with the control group. These results showed that APCs with longer half-life and double light exposure lead to superior outcomes in cancer cell-targeted NIR-PIT in an immunocompetent mouse model.

Near-infrared photoimmunotherapy induced tumor cell death enhances tumor dendritic cell migration.

Near-infrared photoimmunotherapy (NIR-PIT) selectively kills tumor cells to which the photo-absorber dye IR700DX-conjugated antibodies are bound and induces a systemic anti-tumor immune response. NIR-PIT induces immunogenic cell death (ICD), releases damage-associated molecular patterns (DAMPs) molecules from dying tumor cells, and activates dendritic cells (DCs). However, it is unclear whether NIR-PIT affects migration of tumor-infiltrating (Ti)-DCs to draining lymph nodes (dLNs), where a systemic anti-tumor response is induced. Here, we utilized in vivo photolabeling of Ti-DCs in tumors in photoconvertible protein Kikume Green-Red (KikGR) mice to show that NIR-PIT enhanced migration of Ti-DCs including cDC1s, cDC2s, and CD326+ DCs to dLNs. This effect was abolished by blocking adenosine triphosphate (ATP), one of the DAMPs molecules, as well as by inhibition of Gαi signaling by pertussis toxin. Thus, ICD induction by NIR-PIT stimulates Ti-DC migration to dLNs via ATP-P2X7 receptor and Gαi protein-coupled receptor signaling pathways and may augment tumor antigen presentation to induce anti-tumor T cells in dLNs.

Comparison of the Effectiveness of IgG Antibody versus F(ab')2 Antibody Fragment in CTLA4-Targeted Near-Infrared Photoimmunotherapy.

Near-infrared photoimmunotherapy (NIR-PIT) is a novel cancer treatment modality that utilizes antibody-photoabsorber conjugates (APCs) and selectively kills target cells after irradiation with NIR light. Originally, NIR-PIT was targeted against cancer cell surface antigens, but as it became clear that NIR-PIT induced a strong immune response, an effort was made to target selected immune cell populations in the tumor microenvironment to encourage an even stronger immune response. Thus, CD25-targeted NIR-PIT and cytotoxic T-lymphocyte associated protein 4 (CTLA4)-targeted NIR-PIT were developed to kill regulatory T cells (Tregs) in conjunction with cancer-cell-targeted NIR-PIT, in order to amplify the host immune response. It was found that CD25-targeted NIR-PIT, using an antibody with the Fc portion removed, led to better results than the unmodified anti-CD25 antibody-directed NIR-PIT presumably because of a negative effect on activated T cells. The aim of this study was to compare the efficacy of an antibody fragment [anti-CTLA4-F(ab')2] and a whole antibody (anti-CTLA4-IgG) for NIR-PIT. There was no significant difference in NIR-PIT-induced Treg killing between the anti-CTLA4-F(ab')2 and anti-CTLA4-IgG antibodies. Although both the antibody and the antibody fragment resulted in significant tumor growth inhibition, the antibody induced more robust CD8+ T cell activation in ipsilateral lymph nodes and was more effective compared to the antibody fragment. The slower clearance of the anti-CTLA4-IgG APC enhanced antitumor immunity by promoting T cell priming in lymph nodes. In conclusion, unlike the results with CD25 where modified antibodies produced superior results to unmodified antibodies, anti-CTLA4-IgG antibody-based NIR-PIT proved more effective in reducing tumor growth than anti-CTLA4-F(ab')2 antibody-based NIR-PIT.

Upregulation of REV7 correlates with progression of malignant melanoma.

REV7 is a multifunctional protein implicated in DNA damage tolerance, cell cycle control, and gene expression, and is involved in the carcinogenesis of various human tumors. It has been reported that REV7 expression is associated with ultraviolet-induced mutagenesis; however, the role of REV7 expression in skin cancers, including malignant melanomas, remains unclear. In the present study, we investigated the clinical and biological significance of REV7 in malignant melanoma. Levels of REV7 expression in human skin cancers were evaluated immunohistochemically. Positive expression of REV7 was frequently observed in malignant melanomas, as well as in squamous cell carcinomas and basal cell carcinomas. Enhanced immunoreactivity to REV7 was closely linked with cell proliferation assessed by Ki-67 labeling indexes in the three skin cancers, and was related with tumor thickness in malignant melanomas. REV7 depletion in malignant melanoma cells MEWO and G361 suppressed cell proliferation, migration, and invasion abilities. REV7 depletion also affected the expression of intracellular signaling molecules AKT and ERK in MEWO cells, resulting in downregulation of ERK signal activation. In addition, REV7 depletion facilitated sensitivity to cisplatin, but not to dacarbazine, in MEWO cells. Our results suggest that REV7 expression correlates with disease progression of malignant melanoma.

Adductor longus: An anatomical study to better understand groin pain.

We investigated the shear modulus-passive force relationship in the hip adductor longus (AL) muscles of human cadavers and explored the effect of muscle architecture on the elastic properties of the AL muscle using shear wave elastography (SWE). Nine AL muscles were harvested from a soft, embalmed cadaver. The AL muscles were affixed to a custom-built device comprising two clamps, a pulley, and a cable to provide passive loads, which were increased from 0 to 600 g in 60-g increments. The shear modulus of the AL muscle was measured in the proximal (Pro), middle (Mid), and distal (Dis) regions. The masses and anatomical cross-sectional areas (ACSAs) of the AL muscles were measured. The shear modulus-passive load relationship of each tested muscle region was analyzed by fitting a least-squares regression line. Moreover, the rate of increase in the shear modulus per unit load (s) was calculated. The shear modulus and passive force were linearly correlated for all AL muscles in each region (p < 0.01). The mean coefficients of determination (R2 ) for Pro, Mid, and Dis were 0.989, 0.986, and 0.982, respectively. The rate of increase in the shear modulus per unit load significantly correlated with the reciprocal of the muscle mass (r = 0.77, p = 0.02) and ACSA (r = 0.43, p = 0.03). Shear wave elastography can be used as an indirect measure of passive force in any region of the AL muscle. Additionally, the rate of increase in the shear modulus per unit load could be associated with muscle architectural parameters.

Nanog is a promising chemoresistant stemness marker and therapeutic target by iron chelators for esophageal cancer.

Esophageal cancer is a disease showing poor prognosis. Although combination chemotherapy using cisplatin (CDDP) and 5-fluorouracil is standard for unresectable esophageal cancer, the response rate is 35%. Cancer stem cells (CSCs) and inflammation are reportedly responsible for the poor prognosis of esophageal cancer. However, comprehensive analyses have not been conducted and proposals for progress remain lacking. Iron is known to be a key factor in the stemness of CSCs. Our study focused on the therapeutic potential of iron control using iron chelators for CSCs in esophageal cancer. Among 134 immunohistochemically analyzed cases, Nanog expression was high in 98 cases and low in 36 cases. High Nanog expression correlated with low overall and disease-free survivals. The iron chelators deferasirox (DFX) and SP10 suppressed the proliferation and expression of stemness markers in TE8 and OE33 cells. DFX and SP10 did not induce compensatory interleukin (IL)-6 secretion, although CDDP did result in high induction. Moreover, BBI608 and SSZ, as other CSC-targeting drugs, could not suppress the expression of stemness markers. Overall, Nanog expression appears related to poor prognosis in esophageal cancer patients, and inhibition of stemness and compensatory IL-6 secretion by iron chelators may offer a novel therapeutic strategy for esophageal cancer.

Diagnostic imaging in near-infrared photoimmunotherapy using a commercially available camera for indocyanine green.

Near-infrared photoimmunotherapy (NIR-PIT) is a new type of cancer treatment, which was recently approved in Japan for patients with inoperable head and neck cancer. NIR-PIT utilizes antibody-IRDye700DX (IR700) conjugates and NIR light at a wavelength of 690 nm. NIR light exposure leads to physicochemical changes in the antibody-IR700 conjugate cell receptor complex, inducing rapid necrotic cell death. Just as fluorescence guided surgery is useful for surgeons to resect tumors completely, real-time information of tumor locations would help clinicians irradiate NIR light more precisely. IR700 is a fluorescence dye that emits at 702 nm; however, there is no clinically available device optimized for detecting this fluorescence. On the other hand, many indocyanine green (ICG) fluorescence imaging devices have been approved for clinical use. Therefore, we investigated whether LIGHTVISION, one of the clinically available ICG cameras, could be employed for tumor detection. We hypothesized that irradiation with even low-power 690-nm laser light, attenuated by 99% with a neutral-density filter, could be detected with LIGHTVISION without fluorescence decay or therapeutic effect because of the long emission tail of IR700 beyond 800 nm (within the detection range of LIGHTVISION). We demonstrated that the LIGHTVISION camera, originally designed for ICG detection, can detect the tail of IR700 fluorescence in real time, thus enabling the visualization of target tumors.