Perspective view of allogeneic IgG tumor immunotherapy.

Allogeneic tumors are eradicated by host immunity; however, it is unknown how it is initiated until the report in Nature by Yaron Carmi et al. in 2015. Currently, we know that allogeneic tumors are eradicated by allogeneic IgG via dendritic cells. AlloIgG combined with the dendritic cell stimuli tumor necrosis factor alpha and CD40L induced tumor eradication via the reported and our proposed potential signaling pathways. AlloIgG triggers systematic immune responses targeting multiple antigens, which is proposed to overcome current immunotherapy limitations. The promising perspectives of alloIgG immunotherapy would have advanced from mouse models to clinical trials; however, there are only 6 published articles thus far. Therefore, we hope this perspective view will provide an initiative to promote future discussion.

Oncolytic virotherapy evolved into the fourth generation as tumor immunotherapy.

BACKGROUND: Oncolytic virotherapy (OVT) is a promising anti-tumor modality that utilizes oncolytic viruses (OVs) to preferentially attack cancers rather than normal tissues. With the understanding particularly in the characteristics of viruses and tumor cells, numerous innovative OVs have been engineered to conquer cancers, such as Talimogene Laherparepvec (T-VEC) and tasadenoturev (DNX-2401). However, the therapeutic safety and efficacy must be further optimized and balanced to ensure the superior safe and efficient OVT in clinics, and reasonable combination therapy strategies are also important challenges worthy to be explored. MAIN BODY: Here we provided a critical review of the development history and status of OVT, emphasizing the mechanisms of enhancing both safety and efficacy. We propose that oncolytic virotherapy has evolved into the fourth generation as tumor immunotherapy. Particularly, to arouse T cells by designing OVs expressing bi-specific T cell activator (BiTA) is a promising strategy of killing two birds with one stone. Amazing combination of therapeutic strategies of OVs and immune cells confers immense potential for managing cancers. Moreover, the attractive preclinical OVT addressed recently, and the OVT in clinical trials were systematically reviewed. CONCLUSION: OVs, which are advancing into clinical trials, are being envisioned as the frontier clinical anti-tumor agents coming soon.

Gut microbiota homeostasis restoration may become a novel therapy for breast cancer.

Breast cancer is the most diagnosed cancer in women. It significantly impairs a patient's physical and mental health. Gut microbiota comprise the bacteria residing in a host's gastrointestinal tract. Through studies over the last decade, we now know that alterations in the composition of the gut microbiome are associated with protection against colonization by pathogens and other diseases, such as diabetes and cancer. This review focuses on how gut microbiota can affect breast cancer development through estrogen activity and discusses the types of bacteria that may be involved in the onset and the progression of breast cancer. We also describe potential therapies to curtail the risk of breast cancer by restoring gut microbiota homeostasis and reducing systemic estrogen levels. This review will further explore the relationship between intestinal microbes and breast cancer and propose a method to treat breast cancer by improving intestinal microbes. We aimed at discovering new methods to prevent or treat BC by changing intestinal microorganisms.

The old CEACAMs find their new role in tumor immunotherapy.

Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) contain 12 family members(CEACAM1、CEACAM3、CEACAM4、CEACAM5、CEACAM6、CEACAM7、CEACAM8、CEACAM16、CEACAM18、CEACAM19、CEACAM20 and CEACAM21)and are expressed diversely in different normal and tumor tissues. CEA (CEACAM5) has been used as a tumor biomarker since 1965. Here we review the latest research and development of the structures, expression, and function of CEACAMs in normal and tumor tissues, and their application in the tumor diagnosis, prognosis, and treatment. We focus on recent clinical studies of CEA targeted cancer immunotherapies, including bispecific antibody (BsAb) for radio-immuno-therapy and imaging, bispecific T cell engager (BiTE) and chimeric antigen receptor T cells (CAR-T). We summarize the promising clinical relevance and challenges of these approaches and give perspective view for future research. This review has important implications in understanding the diversified biology of CEACAMs in normal and tumor tissues, and their new role in tumor immunotherapy.

Correction to: The old CEACAMs find their new role in tumor immunotherapy.

Correction is needed to the original version of this article.

Novel transcription regulatory sequences and factors of the immune evasion protein ICP47 (US12) of herpes simplex viruses.

BACKGROUND: Herpes simplex virus (HSV) can cause encephalitis. Its infected cell polypeptide 47 (ICP47), encoded by immediate-early gene US12, promotes immune escape. ICP47 was modified in the clinically approved oncolytic HSV (oHSV) T-Vec. However, transcription regulatory sequence (TRS) and transcription regulatory factor (TRF) of HSV US12 are seldom reported. METHODS: Previously, our laboratory isolated a new HSV strain named HSV-1-LXMW from a male patient with oral herpes in Beijing, China. Firstly, the genetic tree was used to analyze its genetic relationship. The US12 TRS and TRF in HSV-1-LXMW were found by using predictive software. Secondly, the further verification by the multi-sequence comparative analysis shown that the upstream DNA sequence of HSV US12 gene contained the conserved region. Finally, the results of literature search shown that the expression of transcription factors was related to the tissue affinity of HSV-1 and HSV-2, so as to increase the new understanding of the transcriptional regulation of HSV biology and oncolytic virus (OVs) therapy. RESULTS: Here we reported the transcriptional regulation region sequence of our new HSV-1-LXMW, and its close relationship with HSV-1-CR38 and HSV-1-17. Importantly we identified eight different kinds of novel TRSs and TRFs of HSV US12 for the first time, and found they are conserved among HSV-1 (c-Rel, Elk-1, Pax-4), HSV-2 (Oct-1, CF2-II, E74A, StuAp) or both HSVs (HNF-4). The TRFs c-Rel and Oct-1 are biologically functional respectively in immune escape and viral replication during HSV infection. CONCLUSIONS: Our findings have important implication to HSV biology, infection, immunity and oHSVs.

Anticancer bioactive peptide (ACBP) inhibits gastric cancer cells by upregulating growth arrest and DNA damage-inducible gene 45A (GADD45A).

Recently, we reported that anticancer bioactive peptide (ACBP), purified from goat spleens immunized with human gastric cancer extracts, significantly inhibited gastric cancer cells in vitro and gastric tumors in vivo via repressing cell growth and promoting apoptosis, making it a promising potential biological anticancer drug. However, it is not known what genes are functionally required for the ACBP effects. Here, we first found that two tumor suppressor genes, cyclin-dependent kinase inhibitor 2B (CDKN2B) and growth arrest and DNA damage-inducible alpha (GADD45A), were upregulated significantly in the cells with ACBP treatment by microarray screening and the findings were validated by real-time RT-PCR. Next, GADD45A mRNA and protein expressions were downregulated in the gastric cancer cells by lentivirus-mediated RNAi; then, cell viability, cell cycle, and apoptosis were assayed by MTT and flow cytometry. Interestingly, our results indicated that cell viability was not dependent on GADD45A without ACBP treatment; however, cell sensitivity to ACBP was significantly decreased in ACBP-treated gastric cancer cells with GADD45A downregulation. Therefore, we demonstrate that GADD45A was functionally required for ACBP to inhibit gastric cancer cells, suggesting that GADD45A may become a biomarker for ACBP sensitivity. Our findings have significant implications on the molecular mechanism understanding, biomarker development, and anticancer drug development of ACBP.

Label-retaining liver cancer cells are relatively resistant to sorafenib.

OBJECTIVE: The standard therapy for advanced hepatocellular carcinoma (HCC) is sorafenib, with most patients experiencing disease progression within 6 months. Label-retaining cancer cells (LRCC) represent a novel subpopulation of cancer stem cells (CSC). The objective was to test whether LRCC are resistant to sorafenib. METHODS: We tested human HCC derived LRCC and non-LRCC before and after treatment with sorafenib. RESULTS: LRCC derived from human HCC are relatively resistant to sorafenib. The proportion of LRCC in HCC cell lines is increased after sorafenib while the general population of cancer cells undergoes growth suppression. We show that LRCC demonstrate improved viability and toxicity profiles, and reduced apoptosis, over non-LRCC. We show that after treatment with sorafenib, LRCC upregulate the CSC marker aldehyde dehydrogenase 1 family, wingless-type MMTV-integration-site family, cell survival and proliferation genes, and downregulate apoptosis, cell cycle arrest, cell adhesion and stem cells differentiation genes. This phenomenon was accompanied by non-uniform activation of specific isoforms of the sorafenib target proteins extracellular-signal-regulated kinases and v-akt-murine-thymoma-viral-oncogene homologue (AKT) in LRCC but not in non-LRCC. A molecular pathway map for sorafenib treated LRCC is proposed. CONCLUSIONS: Our results suggest that HCC derived LRCC are relatively resistant to sorafenib. Since LRCC can generate tumours with as few as 10 cells, our data suggest a potential role for these cells in disease recurrence. Further investigation of this phenomenon might provide novel insights into cancer biology, cancer recurrence and drug resistance with important implications for the development of novel cancer therapies based on targeting LRCC.

Ovarian Microcystic Stromal Tumor with Significant Nestin Expression: A Unique Case.

Ovary microcystic stromal tumor (MCST) is an extremely rare subtype of sex cord-stromal neoplasm, and only 57 cases have been reported. We herein report a unique case of ovarian MCST with positive nestin expression in a 39-year-old Chinese woman. The tumor showed microcystic stromal histological structures and characteristically expressed the CD10, WT-1, and Ki67 proteins. A molecular analysis identified a point mutation (c.110C > T) in exon 3 of the CTNNB1 gene. To our knowledge, no report has described a case of ovarian MCST with positive staining for nestin protein. Our study provides new insights into the tumor biology of ovarian MCST.

Gut microbiota plays a significant role in gout.

With the development of social economy, the incidence of gout is increasing, which is closely related to people's increasingly rich diet. Eating a diet high in purine, fat, sugar and low-fibre for a long time further aggravates gout by affecting uric acid metabolism. The renal metabolism mechanism of uric acid has been thoroughly studied. To find a new treatment method for gout, increasing studies have recently been conducted on the mechanism of intestinal excretion, metabolism and absorption of uric acid. The most important research is the relationship between intestinal microbiota and the risk of gout. Gut microbiota represent bacteria that reside in a host's gastrointestinal tract. The composition of the gut microbiota is associated with protection against pathogen colonization and disease occurrence. This review focuses on how gut microbiota affects gout through uric acid and discusses the types of bacteria that may be involved in the occurrence and progression of gout. We also describe potential therapy for gout by restoring gut microbiota homeostasis and reducing uric acid levels. We hold the perspective that changing intestinal microbiota may become a vital method for effectively preventing or treating gout.

Tumor-initiating label-retaining cancer cells in human gastrointestinal cancers undergo asymmetric cell division.

Label-retaining cells (LRCs) have been proposed to represent adult tissue stem cells. LRCs are hypothesized to result from either slow cycling or asymmetric cell division (ACD). However, the stem cell nature and whether LRC undergo ACD remain controversial. Here, we demonstrate label-retaining cancer cells (LRCCs) in several gastrointestinal (GI) cancers including fresh surgical specimens. Using a novel method for isolation of live LRCC, we demonstrate that a subpopulation of LRCC is actively dividing and exhibits stem cells and pluripotency gene expression profiles. Using real-time confocal microscopic cinematography, we show live LRCC undergoing asymmetric nonrandom chromosomal cosegregation LRC division. Importantly, LRCCs have greater tumor-initiating capacity than non-LRCCs. Based on our data and that cancers develop in tissues that harbor normal-LRC, we propose that LRCC might represent a novel population of GI stem-like cancer cells. LRCC may provide novel mechanistic insights into the biology of cancer and regenerative medicine and present novel targets for cancer treatment.

Recent Advances on the Molecular Mechanism and Clinical Trials of Venous Thromboembolism.

Venous thromboembolism is a condition that includes deep vein thrombosis and pulmonary embolism. It is the third most common cardiovascular disease behind acute coronary heart disease and stroke. Over the past few years, growing research suggests that venous thrombosis is also related to the immune system and inflammatory factors have been confirmed to be involved in venous thrombosis. The role of inflammation and inflammation-related biomarkers in cerebrovascular thrombotic disease is the subject of ongoing debate. P-selectin leads to platelet-monocyte aggregation and stimulates vascular inflammation and thrombosis. The dysregulation of miRNAs has also been reported in venous thrombosis, suggesting the involvement of miRNAs in the progression of venous thrombosis. Plasminogen activator inhibitor-1 (PAI-1) is a crucial component of the plasminogen-plasmin system, and elevated levels of PAI-1 in conjunction with advanced age are significant risk factors for thrombosis. In addition, it has been showed that one of the ways that neutrophils promote venous thrombosis is the formation of neutrophil extracellular traps (NETs). In recent years, the role of extracellular vesicles (EVs) in the occurrence and development of VTE has been continuously revealed. With the advancement of research technology, the complex regulatory role of EVs on the coagulation process has been gradually discovered. However, our understanding of the causes and consequences of these changes in venous thrombosis is still limited. Therefore, we review our current understanding the molecular mechanisms of venous thrombosis and the related clinical trials, which is crucial for the future treatment of venous thrombosis.

Long non-coding RNAs and circular RNAs in tumor angiogenesis: From mechanisms to clinical significance.

Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) execute a wide array of functions in physiological and pathological processes, including tumor progression. Angiogenesis, an elaborate multistep process driving new blood vessel formation, accelerates cancer progression by supplying nutrients and energy. Dysregulated lncRNAs and circRNAs can reportedly impact cancer progression by influencing angiogenesis. However, the expanding landscape of lncRNAs and circRNAs in tumor progression-dependent angiogenesis remains largely unknown. This review summarizes the major functions of angiogenic lncRNAs (Angio-LncRs) and angiogenic circRNAs (termed Angio-CircRs) and their cancer mechanisms. Moreover, we highlight the commonalities of lncRNAs and circRNAs in epigenetic, transcriptional, and post-transcriptional regulation as well as illustrate how Angio-LncRs and Angio-CircRs induce cancer onset and progression. We also discuss their potential clinical applications in diagnosis, prognosis, and anti-angiogenic therapies.

DNA barcode to trace the development and differentiation of cord blood stem cells (Review).

Umbilical cord blood transplantation was first reported in 1980. Since then, additional research has indicated that umbilical cord blood stem cells (UCBSCs) have various advantages, such as multi­lineage differentiation potential and potent renewal activity, which may be induced to promote their differentiation into a variety of seed cells for tissue engineering and the treatment of clinical and metabolic diseases. Recent studies suggested that UCBSCs are able to differentiate into nerve cells, chondrocytes, hepatocyte­like cells, fat cells and osteoblasts. The culture of UCBSCs has developed from feeder­layer to feeder­free culture systems. The classical techniques of cell labeling and tracing by gene transfection and fluorescent dye and nucleic acid analogs have evolved to DNA barcode technology mediated by transposon/retrovirus, cyclization recombination­recombinase and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR­associated protein 9 strategies. DNA barcoding for cell development tracing has advanced to include single cells and single nucleic acid mutations. In the present study, the latest research findings on the development and differentiation, culture techniques and labeling and tracing of UCBSCs are reviewed. The present study may increase the current understanding of UCBSC biology and its clinical applications.

Multifunctional Non-Coding RNAs Mediate Latent Infection and Recurrence of Herpes Simplex Viruses.

Herpes simplex viruses (HSVs) often cause latent infection for a lifetime, leading to repeated recurrence. HSVs have been engineered as oncolytic HSVs. The mechanism of the latent infection and recurrence remains largely unknown, which brings great challenges and limitations to eliminate HSVs in clinic and engineer safe oHSVs. Here, we systematically reviewed the latest development of the multi-step complex process of HSV latency and reactivation. Significantly, we first summarized the three HSV latent infection pathways, analyzed the structure and expression of the LAT1 and LAT2 of HSV-1 and HSV-2, proposed the regulation of LAT expression by four pathways, and dissected the function of LAT mediated by five LAT products of miRNAs, sRNAs, lncRNAs, sncRNAs and ORFs. We further analyzed that application of HSV LAT deletion mutants in HSV vaccines and oHSVs. Our review showed that deleting LAT significantly reduced the latency and reactivation of HSV, providing new ideas for the future development of safe and effective HSV therapeutics, vaccines and oHSVs. In addition, we proposed that RNA silencing or RNA interference may play an important role in HSV latency and reactivation, which is worth validating in future.

Mechanisms and Clinical Trials of Hepatocellular Carcinoma Immunotherapy.

Hepatocellular carcinoma (HCC), one of the most common and lethal tumors worldwide, is usually not diagnosed until the disease is advanced, which results in ineffective intervention and unfavorable prognosis. Small molecule targeted drugs of HCC, such as sorafenib, provided only about 2.8 months of survival benefit, partially due to cancer stem cell resistance. There is an urgent need for the development of new treatment strategies for HCC. Tumor immunotherapies, including immune check point inhibitors, chimeric antigen receptor T cells (CAR-T) and bispecific antibodies (BsAb), have shown significant potential. It is known that the expression level of glypican-3 (GPC3) was significantly increased in HCC compared with normal liver tissues. A bispecific antibody (GPC3-S-Fabs) was reported to recruit NK cells to target GPC3 positive cancer cells. Besides, bispecific T-cell Engagers (BiTE), including GPC3/CD3, an aptamer TLS11a/CD3 and EpCAM/CD3, were recently reported to efficiently eliminate HCC cells. It is known that immune checkpoint proteins programmed death-1 (PD-1) binding by programmed cell death-ligand 1 (PD-L1) activates immune checkpoints of T cells. Anti-PD-1 antibody was reported to suppress HCC progression. Furthermore, GPC3-based HCC immunotherapy has been shown to be a curative approach to prolong the survival time of patients with HCC in clinically trials. Besides, the vascular endothelial growth factor (VEGF) inhibitor may inhibit the migration, invasion and angiogenesis of HCC. Here we review the cutting-edge progresses on mechanisms and clinical trials of HCC immunotherapy, which may have significant implication in our understanding of HCC and its immunotherapy.

Cell­cell fusion as an important mechanism of tumor metastasis (Review).

Cell­cell fusion is a dynamic biological phenomenon, which plays an important role in various physiological processes, such as tissue regeneration. Similarly, normal cells, particularly bone marrow­derived cells (BMDCs), may attempt to fuse with cancer cells to rescue them. The rescue may fail, but the fused cells end up gaining the motility traits of BMDCs and become metastatic due to the resulting genomic instability. In fact, cell­cell fusion was demonstrated to occur in vivo in cancer and was revealed to promote tumor metastasis. However, its existence and role may be underestimated, and has not been widely acknowledged. In the present review, the milestones in cell fusion research were highlighted, the evidence for cell­cell fusion in vitro and in vivo in cancer was evaluated, and the current understanding of the molecular mechanisms by which cell­cell fusion occurs was summarized, to emphasize their important role in tumor metastasis. The summary provided in the present review may promote further study into this process and result in novel discoveries of strategies for future treatment of tumor metastasis.

Could gastrointestinal tumor-initiating cells originate from cell-cell fusion in vivo?

Tumor-initiating cells (TICs) or cancer stem cells are believed to be responsible for gastrointestinal tumor initiation, progression, metastasis, and drug resistance. It is hypothesized that gastrointestinal TICs (giTICs) might originate from cell-cell fusion. Here, we systemically evaluate the evidence that supports or opposes the hypothesis of giTIC generation from cell-cell fusion both in vitro and in vivo. We review giTICs that are capable of initiating tumors in vivo with 5000 or fewer in vivo fused cells. Under this restriction, there is currently little evidence demonstrating that giTICs originate from cell-cell fusion in vivo. However, there are many reports showing that tumor generation in vitro occurs with more than 5000 fused cells. In addition, the mechanisms of giTIC generation via cell-cell fusion are poorly understood, and thus, we propose its potential mechanisms of action. We suggest that future research should focus on giTIC origination from cell-cell fusion in vivo, isolation or enrichment of giTICs that have tumor-initiating capabilities with 5000 or less in vivo fused cells, and further clarification of the underlying mechanisms. Our review of the current advances in our understanding of giTIC origination from cell-cell fusion may have significant implications for the understanding of carcinogenesis and future cancer therapeutic strategies targeting giTICs.

Bispecific T cell engagers and their synergistic tumor immunotherapy with oncolytic viruses.

Tumor immunotherapy, especially T cell based therapy, is becoming the main force in clinical tumor therapies. Bispecific T cell engager (BiTE) uses the single chain variable fragments (scFv) of two antibodies to redirect T cells to kill target cells. BiTEs for hematologic tumors has been approved for clinical use, and BiTEs for solid tumors showed therapeutic effects in clinical trials. Oncolytic viruses (OVs) of the adenovirus expressing p53 and herpes simplex virus expressing GM-CSF was approved for clinical use in 2003 and 2015, respectively, while other OVs showed therapeutic effects in clinical trials. However, BiTE and Oncolytic virus (OV) have their own limitations. We propose that OV-BiTE has a synergistic effect on tumor immunotherapy. Feng Yu et al. designed the first OV-BiTE in 2014, which remarkably eradicated tumors in mice. Here we review the latest development of the structure, function, preclinical studies and/or clinical trials of BiTE and OV-BiTE and provide perspective views for optimizing the design of OV-BiTE. There is no doubt that OV-BiTE is becoming an exciting new platform for tumor immunotherapy and will enter clinical trial soon. Exploring the therapeutic effects and safety of OV-BiTE for synergistic tumor immunotherapy will bring new hope to tumor patients.

Ligand binding to the androgen receptor induces conformational changes that regulate phosphatase interactions.

We describe a mechanism for protein phosphatase 2A (PP2A) targeting to the androgen receptor (AR) and provide insight into the more general issue of kinase and phosphatase interactions with AR. Simian virus 40 (SV40) small t antigen (ST) binding to N-terminal HEAT repeats in the PP2A A subunit induces structural changes transduced to C-terminal HEAT repeats. This enables the C-terminal HEAT repeats in the PP2A A subunit, including HEAT repeat 13, to discriminate between androgen- and androgen antagonist-induced AR conformations. The PP2A-AR interaction was used to show that an AR mutant in prostate cancer cells (T877A) is activated by multiple ligands without acquiring the same conformation as that induced by androgen. The correlation between androgen binding to AR and increased phosphorylation of the activation function 1 (AF-1) region implies that changes in AR conformation or chaperone composition are causal to kinase access to phosphorylation sites. However, AF-1 phosphorylation sites are kinase accessible prior to androgen binding. This suggests that androgens can enhance the phosphorylation state of AR either by negatively regulating the ability of the ligand-binding domain to bind phosphatases or by inducing an AR conformation that is resistant to phosphatase action. SV40 ST subverts this mechanism by promoting the direct transfer of PP2A onto androgen-bound AR, resulting in multisite dephosphorylation.