The immunotherapy effect of colorectal cancer is severely compromised by the expression of programmed cell death ligand 1 (PD-L1) on tumor cells and exosomes. Herein, a chimeric peptide engineered photodynamic degrader (NPPM) is developed for colorectal cancer immunotherapy, combining photodynamic degradation of PD-L1 with inhibition of exosomal PD-L1 expression. Among these, NPPM integrates protoporphyrin IX (PpIX) with a PD-L1-targeting peptide sequence (CVRARTR), forming an amphiphilic chimeric peptide to load macitentan (MAC). NPPM demonstrates specific colorectal cancer targeting ability through PD-L1 recognition and generates substantial reactive oxygen species (ROS) upon light irradiation, thereby destroying tumor cells via photodynamic therapy (PDT). More interestingly, PDT not only triggers immunogenic cell death (ICD) to enhance tumor immunogenicity, but also induces PD-L1 degradation in tumor cells. Concurrently, the delivery of MAC synergistically decreases the expression of exosomal PD-L1, thus amplifying the immunotherapeutic effect. The synergistic functions of NPPM result in significant activation of systemic anti-tumor immunity, characterized by increased infiltration of T cells and reduced presence of regulatory T cells, effectively suppressing both primary and metastatic tumors. This study provides a new strategy to degrade the proteins of interest and also proposes a sophisticated mechanism to potentiate immunotherapy by overcoming multiple immunosuppressive factors.

Background The effectiveness of immune checkpoint inhibitors in colorectal cancer (CRC) is limited due to the low tumor neoantigen load and low immune infiltration in most microsatellite-stable (MSS) tumors. This study aimed to develop a mitochondria-targeted photodynamic therapy (PDT) approach to provoke host antitumor immunity of MSS-CRC and elucidate the underlying molecular mechanisms.Methods The role and mechanism of mitochondria-targeted PDT in inhibiting CRC progression and inducing pyroptosis were evaluated both in vitro and in vivo. The immune effects of PDT sensitization on PD-1 blockade were also assessed in CT26 and 4T1 tumor-bearing mouse models.Results Here, we report that PDT using IR700DX-6T, a photosensitizer targeting the mitochondrial translocation protein, may trigger an antitumor immune response initiated by pyroptosis in CRC. Mechanistically, IR700DX-6T-PDT produced reactive oxygen species on light irradiation and promoted downstream p38 phosphorylation and active caspase3 (CASP3)-mediated cleavage of gasdermin E (GSDME), subsequently inducing pyroptosis. Furthermore, IR700DX-6T-PDT enhanced the sensitivity of MSS-CRC cells to PD-1 blockade. Decitabine, a demethylation drug used to treat hematologic neoplasms, disrupted the abnormal methylation pattern of GSDME in tumor cells, enhanced the efficacy of IR700DX-6T-PDT, and elicited a potent antitumor immune response in combination with PD-1 blockade and IR700DX-6T-PDT.Conclusion Our work provides clear a understanding of immunogenic cell death triggered by mitochondria-targeted PDT, offering a new approach for enhancing the efficacy of PD-1 blockade in CRC.

Supplementary Information including Supplementary Tables S1, S2 and S3 and Legends for Supplementary Movies S1 and S2

Real-time image-guided surgery of littermate control mouse using V-1520

Background: Cholangiocarcinoma recurs frequently following excision surgery and is usually inoperable, while radiotherapy, chemotherapy, and immunotherapy are of limited benefit. As palliative care, percutaneous transhepatic cholangial drainage (PTCD) can relieve biliary obstruction, prevent jaundice, and maintain quality of life (QOL), but does not improve overall survival. In contrast, photodynamic therapy (PDT) has been demonstrated to prolong the survival of inoperable cancer patients.Objective: This study evaluated the clinical efficacy of percutaneous transhepatic cholangioscopy (PTCS)-guided PDT following PTCD versus PTCD alone for recurrent inoperable cholangiocarcinoma. Methods: The case files of 39 patients with postoperative recurrence were retrospectively analyzed, including 18 receiving PTCS-guided PDT (PTCS-PDT group) and 21 receiving PTCD only as a control (PTCD group). Survival time was compared by Kaplan-Meier analysis and log-rank test, and QOL by the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-HEP) questionnaire. Clinicodemographic factors, including serum bilirubin and adverse reaction rates, were compared by Student's t-test or Fisher's exact test. The maximum follow-up period was 71 months.Results: Median survival time was significantly longer in the PTCS-PDT group than the PTCD group (23 months vs. 10 months, P = 0.00001). At 6 and 12 months post-treatment, total FACT-HEP score was lower in the PTCS-PDT group (P < 0.05), indicating improved QOL. There was no significant difference in total adverse events incidence between groups (19 [51.4%] vs. 15 [71.4%]; P = 0.131). Conclusion: PTCS-guided PDT can prolong survival and improve the QOL of patients with postoperative chol-angiocarcinoma recurrence without increasing complications.Significant and/or new findings: Compared to PTCD alone, PTCS-guided PDT significantly prolonged the survival time of patients with postoperative recurrent extrahepatic cholangiocarcinoma. Photodynamic therapy also improved patient quality of life by facilitating timely removal of the PTCD drainage tube. PTCS-guided PDT did not increase surgery-related complications except for skin phototoxicity, which can be easy avoided and treated.

This study investigated the exosomal circular RNAs (CircRNAs) produced by tumor-associated macrophages and delivered into the microenvironment of cholangiocarcinoma cells in order to use them as molecular targets for clinical therapy. Tumor-associated M2 macrophages (TAMs) were induced from THP-1 cells and identified by flow cytometry. The TAM-secreted exosomes were isolated from conditioned medium and a CircRNA microarray assay was performed to identify CircRNAs that were uniquely expressed in the isolated exosomes. Circ_0020256 was especially identified based on having the highest differential expression level among all of the CircRNA candidates. In vitro and in vivo experiments were performed to assess the effects of TAMs, exosomes, and Circ_0020256 on the growth and migration of cholangiocarcinoma (CCA) cells. The induced TAMs promoted the proliferation, migration, and invasion of CCA cells and those effects were mediated by exosomes secreted by the TAMs. In CCA cells (RBE and HCCC-9810), Circ_0020256 significantly promoted cellular activity by interacting with its intra-cellular microRNA target, miR-432-5p. In contrast, overexpression of transcription factor E2F3 in CCA cells restored the CCA cellular activities that were inhibited by miR-432-5p. On the other hand, treatment with small interference RNA (siRNA) for Circ_0020256 inhibited CCA cell proliferation, migration, and invasion both in vitro and in vivo. In conclusion, Circ_0020256 in TAM-secreted exosomes promoted the proliferation, migration, and invasion of CCA cells, and that promotional activity was regulated via a Circ_0020256/miR-432-5p/E2F3 axis.

Long non-coding RNAs (lncRNAs) are broadly transcribed in the genome of human and play critical roles in the progression of multiple diseases. Long non-coding HOXB cluster antisense RNA 1 (HOXB-AS1) is a tumor exciter in various cancers. This study aimed to investigate the involvement of HOXB-AS1 in hepatocellular carcinoma (HCC). In the following study, HOXB-AS1 was unveiled to be highly expressed in HCC tissues as opposed to normal tissues. Silencing of HOXB-AS1 led to the loss of proliferation, migration, and invasiveness of HCC cells, namely Hep3B and Huh7. Moreover, the data showed that expression levels of HOXB-AS1 contribute significantly to the patient’s survival rates. Otherwise, HOXB-AS1 levels in the serum of patients proved HOXB-AS1 as a biomarker for analysis and treatment of HCC. In summary, this study highlights HOXB-AS1 as key upregulated lncRNA in HCC which being an oncogene can cause proliferation and metastasis of HCC cells. The results also highlighted HOXB-AS1 as a promising biomarker for early diagnosis and prognosis of patients with HCC.

Introduction The diagnosis and treatment of osteoporosis, a frequent age-related metabolic bone disorder, remain incomprehensive and challenging. The potential regulatory role of lncRNA XIST and sphingosine kinase 1 (SPHK1) pathway need experimental investigations. Materials and methods RAW264.7 cells and BMMs were obtained for in vitro studies and 30 ng/mL RANKL was implemented for induction of osteoclast differentiation. The suppressing of lncRNA XIST, SPHK1 and fused in sarcoma (FUS) was achieved using small hairpin RNA, while overexpression of XIST and FUS was constructed by pcDNA3.1 vector system. Tartrate-resistant acid phosphatase (TRAP) staining was used for observation of formation of osteoclasts. RNA-pulldown analysis and RNA binding protein immunoprecipitation (RIP) was implemented for measuring mRNA and protein interactions. RT-qPCR was conducted to determining mRNA expression, whereas ELISA and Western blotting assay was performed for monitoring protein expression. Results RANKL induced osteoclast differentiation and upregulated expression of osteoclastogenesis-related genes that included NFATc1, CTSK, TRAP and SPHK1 and the level of lncRNA XIST in both RAW264.7 cells and BMMs. However, knockdown of lncRNA XIST or suppressing SPHK1 significantly reserved the effects of RANKL. LncRNA XIST was further demonstrated to be interacted with FUS and increased the stability of SPHK1, indicating its ability in promoting osteoclast differentiation through SPHK1/S1P/ERK signaling pathway. Conclusion LncRNA XIST promoted osteoclast differentiation via interacting with FUS and upregulating SPHK1/S1P/ERK pathway.

Photodynamic therapy (PDT) is a non-invasive or minimally-invasive treatment which applies photosensitizers (PSs) to create reactive oxygen species (ROS) exposed to light trigger to destroy cancer cells. PDT can activate host anti-tumor immune responses but not powerful enough to kill metastatic tumors. Because of its carrier advantage, imaging, and therapeutic function together with enhanced permeability and retention (EPR) effect, nano-materials have already been used in photo-immunotherapy. Herein, photodynamic immunotherapy (PDIT) based on nanotechnology seems to be a hopeful new form of cancer therapy. In this article, we firstly summarize the recent development in photodynamic immunotherapy based on nanotechnology.

BACKGROUND/AIMS:IR700DX-6T and IR700DX-mbc94 are two chemically synthesized photosensitizers (PSs) that target the translocator protein (TSPO) and type 2 cannabinoid receptor (CB2R), respectively, for photodynamic therapy (PDT) of cancer. Recently, we found that IR700DX-6T and IR700DX-mbc94 exhibited high selectivity and efficiency in PDT for breast cancer and malignant astrocytoma. Yet, the phototherapeutic effects of the PSs on pancreatic cancer and underlying mechanisms remain unknown. This study investigated the effect of IR700DX-6T- or IR700DX-mbc94-PDT on pancreatic cancer and whether the treatment involves eliciting anticancer immune responses in support of superior therapeutic efficacy.METHODS:Four pancreatic cancer cell lines were used for in vitro studies. C57BL/6 mice bearing pancreatic cancer cell-derived xenografts were generated for in vivo studies regarding the therapeutic effects of IR700DX-6T-PDT and IR700DX-mbc94-PDT on pancreatic cancer. The immunostimulatory or immunosuppressive effects of IR700DX-6T-PDT and IR700DX-mbc94-PDT were examined by detecting CD8+ T cells, regulatory T cells (Tregs), and dendritic cells (DCs) using flow cytometry and immunohistochemistry (IHC).RESULTS:TSPO and CB2R were markedly upregulated in pancreatic cancer cells and tissues. Both IR700DX-6T-PDT and IR700DX-mbc94-PDT significantly inhibited pancreatic cancer cell growth in a dose- and time-dependent manner. Notably, assessment of anticancer immune responses revealed that both IR700DX-6T-PDT and IR700DX-mbc94-PDT significantly induced CD8+ T cells, promoted maturation of DCs, and suppressed Tregs, with stronger effects exerted by IR700DX-6T-PDT compared to IR700DX-mbc94-PDT.CONCLUSIONS:IR700DX-6T-PDT and IR700DX-mbc94-PDT involves eliciting anticancer immune responses. Our study has also implicated that PDT in combination with immunotherapy holds promise to improve therapeutic efficacy for patients with pancreatic cancer.

Photodynamic therapy (PDT) is a clinically approved therapeutic strategy that combines a specific wavelength of light and light-activated photosensitizers (PSs). The usage of PDT for cancer treatment is often hampered by the lack of tumor selectivity of PSs, which may cause photodamage to surrounding normal tissues. Recently, translocator protein (TSPO) has attracted great interest as a tumor biomarker, whose expression correlates with tumor aggressiveness. In this study, we report the development of a series of novel TSPO-PSs based on quinazoline, pyrazolopyrimidine, and tetrahydrocarbazole structures. These TSPO-PSs bind to TSPO with nanomolar affinities and demonstrated efficient and target-specific PDT effect upon light irradiation. Therefore, they may have great potential in the treatment of tumors associated with high-TSPO expression.

Black phosphorus quantum dots(BPQDs) have shown a good application prospect in the field of tumor therapy due to their photoelectric effect and good biodegradability. Due to the active endocytosis and fast metabolic efficiency of tumor cells, BPQDs are easy to be absorbed by tumor cells. However, this does not guarantee that BPQDs will be completely targeted to tumor cells, and normal cells will also absorb BPQDs. Because the cell membrane is negatively charged, BPQDs are also negatively charged and are not easily absorbed by cells under the action of electrostatic repulsion. Surface pegylation is the most common modification method of black phosphorus at present. However, surface pegylation can reduce the uptake of BPQDs by tumor cells. Positive PEG is also easy to be recognized and swallowed by the reticuloendothelial system. The inherent instability and poor tumor targeting of BPQDs under physiological conditions limit further research and clinical application. For this purpose, we selected cationic polymer polyethylenimine (PEI) to modify BPQDs and then added RGD peptides targeting tumor cells. An outer layer of negatively charged PEG+DMMA makes the nanosystem more stable . In the acidic environment of the tumor, the PEG layer has a charge reversal, and the positively charged PEI and the RGD polypeptide BPQDs targeted by the tumor cells are released into the tumor cells. It provides a new method for efficiently and accurately transporting BPQDs, a novel photosensitive nanomaterial, into tumor cells for photodynamic therapy.

Abscopal effect is an attractive cancer therapeutic effect referring to tumor regression at a location distant from the primary treatment site. Immunogenic cell death (ICD) offers a mechanistic link between the primary and remote therapeutic effects by activating favorable anti-tumor immune responses. In this study, we induced ICD in colorectal cancer (CRC) cell lines in vitro and in vivo by targeting the 18 kDa translocator protein (TSPO), a mitochondrial receptor overexpressed in CRC. Photodynamic therapy (PDT) using a TSPO-targeted photosensitizer, IR700DX-6T, caused effective apoptotic cell death in fourteen CRC cell lines. In a syngeneic immunocompetent CRC mouse model, the growth of tumors subjected to TSPO-PDT was greatly suppressed. Remarkably, untreated tumors in the opposing flank also showed marked growth suppression. Dendritic and CD8+ T cells were activated after TSPO-PDT treatment, accompanied by decreased Treg cells in both treated and non-treated tumors. In addition, a cancer vaccine developed from TSPO-PDT produced a significant tumor inhibition effect. These results indicate that TSPO-PDT could not only directly suppress tumor growth but also dramatically provoke host anti-tumor immunity, highlighting the potential of TSPO-PDT as a successful therapeutic for CRC that exhibits systemic effects. STATEMENT OF SIGNIFICANCE: Abscopal effect is an attractive cancer therapeutic effect referring to tumor regression at a location distant from the primary treatment site. Immunogenic cell death (ICD) offers a mechanistic link between the primary and remote therapeutic effects by activating favorable anti-tumor immune responses. In this study, we report a new therapeutic approach that can reduce the growth of multiple CRC cell lines by inducing ICD. Notably, a direct and abscopal effect was observed in mouse tumor-derived MC38 cells when injected into syngeneic immunocompetent mice. If comparable effects could be achieved in humans, it would establish a novel paradigm for treating micro- and macro-metastasis.

INTRODUCTION:Osteoporosis, a common skeletal disorder mainly affecting postmenopausal women, is characterized by the imbalance between osteogenesis and osteoclastogenesis. Circ_0134944 has been recently found to be upregulated in postmenopausal osteoporosis (PMOP) patients. However, its role in osteogenesis remains unknown. Here we aimed to explore the role of circ_0134944 in osteogenesis and reveal the underlying mechanism.METHODS:qRT-PCR was used to determine the expression of circ_0134944, miR-127-5p, PDX1 and SPHK1 in the blood mononuclear cells (BMCs) of PMOP patients. Bone marrow mesenchymal stem cells (BMSCs) were used as the cellular model. Western blotting and qRT-PCR were used to determine the expression of osteogenesis-related genes (Runx2, OPN, OCN). ALP and Alizarin Red S staining were performed to evaluate osteogenic differentiation. The interactions between circ_0134944 and miR-127-5p, miR-127-5p and PDX1, PDX1 and SPHK1 were determined by dual-luciferase reporter and ChIP assay.RESULTS:Circ_0134944, PDX1 and SPHK1 were upregulated while miR-127-5p was downregulated in PMOP patients. Enhanced expression of circ_0134944 suppressed osteogenesis, which was then reversed by miR-127-5p overexpression. The binding between circ_0134944 and miR-127-5p, PDX1 and miR-127-5p were confirmed by dual-luciferase reporter assay. Moreover, PDX1 was enriched in the promoter region of SPHK1, and SPHK1 overexpression prevented the promotion of osteogenesis induced by miR-127-5p overexpression.CONCLUSIONS:Taken together, these results demonstrate that circ_0134944 inhibit osteogenesis via miR-127-5p/PDX1/SPHK1 axis. Thus, the present study offered evidence that circ_0134944/miR-127-5p/PDX1/SPHK1 axis could be a potential therapeutic target for PMOP.

Photodynamic therapy (PDT) is a promising non-invasive therapy approach for various diseases including malignant tumor. The process of PDT involves three interrelated aspects, namely photosensitizer (PS), light source, and oxygen, among which PS is the decisive factor that determines its anticancer efficiency. There exist some defects in currently applied PDT, such as inadequate production of reactive oxygen species (ROS), poor penetration of exciting light, insufficient oxygen supply, and nonselective distribution of PS. With unique physicochemical and optical properties, two-dimensional nanomaterials (2DNMs) have aroused great interest in biomedical fields. 2DNMs-based PDT is promising to significantly improve antitumor efficacy compared to conventional PDT. In this review, we will firstly introduce the underlying mechanism of PDT and how 2DNMs are absorbed and distribute inside tumor cells. After that, we will not only illustrate how 2DNMs-based PDT can enhance tumor-killing efficacy and minimize side-effects through conquering the above-mentioned defects of conventional PDT and the preparation process of 2DNMs, but also elaborate recent advances about 2DNMs-based PDT. Lastly, we will summarize the challenges and future prospects of 2DNMs-based PDT.

Following the publication of article [1], the authors found that the images of Transwell Matrigel invasion (Fig. 7d) are incorrect.

Abstract Purpose: Pancreatic cancer is among the most aggressive malignancies and is rarely discovered early. However, pancreatic “incidentalomas,” particularly cysts, are frequently identified in asymptomatic patients through anatomic imaging for unrelated causes. Accurate determination of the malignant potential of cystic lesions could lead to life-saving surgery or spare patients with indolent disease undue risk. Current risk assessment of pancreatic cysts requires invasive sampling, with attendant morbidity and sampling errors. Here, we sought to identify imaging biomarkers of high-risk pancreatic cancer precursor lesions. Experimental Design: Translocator protein (TSPO) expression, which is associated with cholesterol metabolism, was evaluated in premalignant and pancreatic cancer lesions from human and genetically engineered mouse (GEM) tissues. In vivo imaging was performed with [18F]V-1008, a TSPO-targeted PET agent, in two GEM models. For image-guided surgery (IGS), V-1520, a TSPO ligand for near-IR optical imaging based upon the V-1008 pharmacophore, was developed and evaluated. Results: TSPO was highly expressed in human and murine pancreatic cancer. Notably, TSPO expression was associated with high-grade, premalignant intraductal papillary mucinous neoplasms (IPMNs) and pancreatic intraepithelial neoplasia (PanIN) lesions. In GEM models, [18F]V-1008 exhibited robust uptake in early pancreatic cancer, detectable by PET. Furthermore, V-1520 localized to premalignant pancreatic lesions and advanced tumors enabling real-time IGS. Conclusions: We anticipate that combined TSPO PET/IGS represents a translational approach for precision pancreatic cancer care through discrimination of high-risk indeterminate lesions and actionable surgery.

Currently, photodynamic therapy (PDT) of primary tumors in peritoneal organs is limited by the lack of specificity of photosensitizers (PSs) and availability of appropriate laparoscopy for accurate and dexterous PDT optical fiber deployment. Invasive procedures are often required in the conventional approach, leads to significant side effects such as bleeding and extended recovery time. The purpose of this study is to design and evaluate a soft robot system for targeted and minimally invasive PDT of intraperitoneal tumors. Our soft robot system is fabricated with silicone materials to enable safe interaction with the abdominal organs. Compared to the conventional laparoscopic device, this soft robot system can be translated, bent, and rotated to reach the desired target by using three high-resolution DC motors. A miniature camera (ENA-10005-AS, Enable Inc.) is integrated with the soft robot to enable the intraoperative image guidance while reaching the target. A hollow channel was created within the soft robot so as to deploy the optical fiber towards the tumor. We conducted interstitial PDT using a peritoneal ovarian tumor mouse model and targeted near infrared photosensitizer. After the PS was injected, the optical fiber was inserted into the tumors through the soft robot. We found that PDT treatment greatly inhibited tumor growth. Our preliminary results suggest that our soft robot system may have great potential in the PDT treatment of intraperitoneal tumors.

Background As an important means of communication, exosomes play an important role in the development of hepatocellular carcinoma (HCC). Methods Bioinformatics analysis, dual-luciferase reporter assays, methylation-specific quantitative PCR, and ChIP-PCR analysis were used to gain insight into the underlying mechanism of miR-21 in HCC. Results The detection of miRNAs in exosomes of HCC showed that miR-21 expression in exosomes was positively correlated with the expression level of miR-21 in cells and negatively correlated with the expression of its target genes PTEN, PTENp1 and TETs. HCC cell-derived exosomes could increase miR-21 and p-Akt expression in HCC cells and downregulate the expression of PTEN, PTENp1 and TETs. MiR-21 inhibitors or PTENp1 overexpression vectors could weaken the effect of the abovementioned exosomes and simultaneously weaken their role in promoting cell proliferation and migration and inhibiting apoptosis. Further studies showed that miR-21 not only directly regulated the expression of PTEN, PTENp1 and TETs but also increased the methylation level of the PTENp1 promoter by regulating the expression of TETs, thereby inhibiting the expression of PTENp1 and further downregulating the expression of PTEN. Conclusions Exosomal miR-21 can regulate the expression of the tumor suppressor genes PTEN and PTENp1 in various ways and affect the growth of HCC cells.