Chinese Journal of Cancer. The 150 most important questions in cancer research and clinical oncology series: questions 6-14 : Edited by Chinese Journal of Cancer

Activation of Sphingomyelin Phosphodiesterase 3 in Liver Regeneration Impedes the Progression of Colorectal Cancer Liver Metastasis Via Exosome-Bound Intercellular Transfer of Ceramides

BACKGROUND & AIMS

The machinery that prevents colorectal cancer liver metastasis (CRLM) in the context of liver regeneration (LR) remains elusive. Ceramide (CER) is a potent anti-cancer lipid involved in intercellular interaction. Here, we investigated the role of CER metabolism in mediating the interaction between hepatocytes and metastatic colorectal cancer (CRC) cells to regulate CRLM in the context of LR.

METHODS

Mice were intrasplenically injected with CRC cells. LR was induced by 2/3 partial hepatectomy (PH) to mimic the CRLM in the context of LR. The alteration of corresponding CER-metabolizing genes was examined. The biological roles of CER metabolism in vitro and in vivo were examined by performing a series of functional experiments.

RESULTS

Induction of LR augmented apoptosis but promoted matrix metalloproteinase 2 (MMP2) expression and epithelial-mesenchymal transition (EMT) to increase the invasiveness of metastatic CRC cells, resulting in aggressive CRLM. Up-regulation of sphingomyelin phosphodiesterase 3 (SMPD3) was determined in the regenerating hepatocytes after LR induction and persisted in the CRLM-adjacent hepatocytes after CRLM formation. Hepatic Smpd3 knockdown was found to further promote CRLM in the context of LR by abolishing mitochondrial apoptosis and augmenting the invasiveness in metastatic CRC cells by up-regulating MMP2 and EMT through promoting the nuclear translocation of β-catenin. Mechanistically, we found that hepatic SMPD3 controlled the generation of exosomal CER in the regenerating hepatocytes and the CRLM-adjacent hepatocytes. The SMPD3-produced exosomal CER critically conducted the intercellular transfer of CER from the hepatocytes to metastatic CRC cells and impeded CRLM by inducing mitochondrial apoptosis and restricting the invasiveness in metastatic CRC cells. The administration of nanoliposomal CER was found to suppress CRLM in the context of LR substantially.

CONCLUSIONS

SMPD3-produced exosomal CER constitutes a critical anti-CRLM mechanism in LR to impede CRLM, offering the promise of using CER as a therapeutic agent to prevent the recurrence of CRLM after PH.

Efficacy of local therapy to metastatic foci in nasopharyngeal carcinoma: large-cohort strictly-matched retrospective study

Background:

Studies of local therapy (LT) to metastatic foci from nasopharyngeal carcinoma (NPC) are inconsistent and controversial. Here, we aimed to explore the survival benefit of LT directed at metastatic foci from NPC.

Methods:

A retrospective analysis was conducted in NPC patients with liver, lung, and/or bone metastases. The postmetastatic overall survival (OS) rate was analyzed using the Kaplan–Meier method and compared by the log-rank test. Multivariate analysis was performed using the Cox hazard model. Subgroup analyses evaluating the effect of LT were performed for prespecified covariates. Propensity score matching was applied to homogenize the compared arms.

Results:

Overall, 2041 of 2962 patients were eligible for analysis. At a median follow-up of 43.4 months, the 5-year OS improved by an absolute difference of 14.6%, from 46.2% in the LT group versus 31.6% in the non-LT group, which led to a hazard ratio of 0.634 for death (p < 0.001). Matched-pair analyses confirmed that LT was associated with improved OS (p = 0.003), and the survival benefits of LT remained consistent in the subcohorts of liver and lung metastasis (p = 0.009 and p = 0.007, respectively) but not of bone metastasis (BoM; p = 0.614). Radiotherapy was predominantly used for BoM and biological effective dose (BED) >60 Gy was found to yield more survival benefit than that of BED ⩽ 60 Gy.

Conclusions:

The addition of LT directed at metastasis has demonstrated an improvement to OS compared with non-LT group in the present matched-pair study, especially for patients with liver and/or lung metastases.

MGP promotes CD8+ T cell exhaustion by activating the NF-κB pathway leading to liver metastasis of colorectal cancer

Matrix Gla protein (MGP) was originally reported as a physiological suppressor of ectopia calcification and has also been reported to be associated with cancer. However, the relation between the biological functions of MGP and the immune response in colorectal cancer (CRC) remains unclear. Here, we investigated the regulatory role of MGP in the immune microenvironment of CRC. MGP expression in CRC samples was assessed by single-cell RNA sequencing and the Gene Expression Omnibus (GEO) database, and confirmed by quantitative real-time Polymerase Chain Reaction (qRT-PCR) and immunohistochemistry analysis of human CRC samples. The effect of MGP on proliferation and invasion of CRC cells was evaluated by in vitro assays involving MGP knockdown and overexpression. Luciferase reporter assay and chromatin immunoprecipitation (ChIP)-qPCR assay were performed to identify transcriptional regulatory sites of the nuclear factor kappa-B (NF-κB) and programmed cell death ligand 1 (PD-L1). In vivo experiments were performed in mouse model of CRC liver metastasis established via spleen injection. The results revealed that MGP was significantly upregulated in cancer cell clusters from the primary CRC or liver metastases, compared with that in the corresponding paracancerous tissues via single-cell RNA sequencing. MGP enriched intracellular free Ca2+ levels and promoted NF-κB phosphorylation, thereby activated PD-L1 expression to promote CD8+ T cell exhaustion in CRC. The luciferase reporter assay and ChIP-qPCR assay indicated that the transcriptional regulation of NF-κB upregulated PD-L1 expression. In vivo, MGP inhibition significantly decreased the rate of CRC liver metastasis, which was further reduced after combined therapy with αPD1 (anti-PD1). In conclusions, this study revealed that MGP can facilitate CD8+ T cell exhaustion by activating the NF-κB pathway, leading to liver metastasis of CRC. The combination of MGP knockdown and αPD1 can synergistically resist liver metastasis of CRC.

Gene Expression-Based Immune Cell Infiltration Analyses of Prostate Cancer and Their Associations with Survival Outcome

Prostate cancer is the second most common cancer and the fifth cause of cancer death in males. Currently, there are no effective therapies for prostate cancer yet, and the status of treatment remains severe. In this study, we analyzed the composition of tumor-infiltrating immune cells (TIICs) in prostate cancer and paracancerous samples based on the gene expression profiles using CIBERSORT. Calculation of the TIIC subset proportions in 52 paired prostate cancer and paracancerous samples showed that their proportions were similar in intergroup and varied in intragroup. Compared with the paracancerous samples, the proportion of M0 macrophages was significantly increased in prostate cancer samples. Cox regression analysis using the TIIC subpopulations as continuous variables revealed that high plasma cell proportion was associated with poor 3-year Disease-Free Survival (DFS) in prostate cancer (hazard ratios = 1.8e-76, p = 0.001). Moreover, three immune clusters, which presented distinct prognosis, were identified using hierarchical clustering analysis based on the proportions of TIIC subpopulations. Among them, cluster 1 had superior 3-year DFS, while cluster 3 showed inferior 3-year DFS (p = 0.025). In summary, our research provided a comprehensive analysis on the TIIC composition in prostate cancer and suggested that both plasma cells and different cluster patterns were associated with the prostate cancer prognosis, which should be helpful for the clinical surveillance and treatment of prostate cancer.

Characteristic And Novel Therapeutic Strategies Of Nasopharyngeal Carcinoma With Synchronous Metastasis

Nasopharyngeal carcinoma (NPC) is rare in Western countries, but its incidence in China and Southeast Asia is notably high. NPC shows a high rate of distant metastasis including metachronous metastasis (mmNPC, metastasis after definitive chemo-radiotherapy) and synchronous metastasis (smNPC, metastasis at initial diagnosis). 4–10% of patients would be diagnosed as smNPC annually, and the survival outcomes of these patients are quite poor. As with few clinical trials exclusively focusing on this population, treatment on smNPC is not unified and many problems remain unsolved. To date, systematic chemotherapy (CT) still remains a fundamental treatment in smNPC. Although no randomized trial has been conducted to compare different CT regimens in smNPC, gemcitabine and taxanes in combination with platinum seem optimal in first-line setting. In second-line CT, there is no consensus: mono-chemotherapy with drugs such as gemcitabine, taxanes or capecitabine could be taken into consideration. Immunotherapy based on checkpoint inhibitors shows promising efficacy both in first-line and in the following lines of therapy. In addition to CT, local therapy in smNPC is also very important. Locoregional radiotherapy (RT) for primary tumor in combination with CT could strikingly increase OS with acceptable toxicities. And local treatment, such as surgery and RT, for metastatic lesions could bring extra survival benefit in patients with solitary or limited metastases. Overall, the present study provides an overview of the literature on the various studies of smNPC.

Role of HGF/c-Met in the treatment of colorectal cancer with liver metastasis

The system of hepatocyte growth factor (HGF) and its receptor c-Met plays a critical role in tumor invasive growth and metastasis. The mortality rate of colorectal cancer (CRC), one of the most commonly diagnosed malignancies, is increased by it gradual development into metastasis, most frequently in the liver. Overexpression of c-Met, the protein tyrosine kinase receptor for the HCF/scatter factor, has been implicated in the progression and metastasis of human colorectal carcinoma. In this study, we aimed to investigate the role of c-Met in CRC liver metastasis and illustrate the clinical impact of regulating HGF/c-Met signaling in patients with CRC liver metastasis. We found that (I) higher levels of c-Met expression (mRNA and Protein) in CRC liver metastasis than primary CRC by assessing the patient tissue samples; (II) a positive correlation of c-Met expression with tumor stages of CRC liver metastasis, as well as c-Met expression in CRC, live metastasis concurred with regional lymph node metastasis; (III) the clinical impact of downregulation of HGF/c-Met signaling on the reduction of proliferation and invasion in CRC liver metastasis. Therefore, we demonstrate that the regulation of HGF/c-Met pathways may be a promising strategy in the treatment of patients with CRC liver metastasis.

The 150 most important questions in cancer research and clinical oncology series: questions 94-101 : Edited by Cancer Communications

Since the beginning of 2017, Cancer Communications (former title: Chinese Journal of Cancer) has published a series of important questions regarding cancer research and clinical oncology, to provide an enhanced stimulus for cancer research, and to accelerate collaborations between institutions and investigators. In this edition, the following 8 valuable questions are presented. Question 94. The origin of tumors: time for a new paradigm? Question 95. How can we accelerate the identification of biomarkers for the early detection of pancreatic ductal adenocarcinoma? Question 96. Can we improve the treatment outcomes of metastatic pancreatic ductal adenocarcinoma through precision medicine guided by a combination of the genetic and proteomic information of the tumor? Question 97. What are the parameters that determine a competent immune system that gives a complete response to cancers after immune induction? Question 98. Is high local concentration of metformin essential for its anti-cancer activity? Question 99. How can we monitor the emergence of cancer cells anywhere in the body through plasma testing? Question 100. Can phytochemicals be more specific and efficient at targeting P-glycoproteins to overcome multi-drug resistance in cancer cells? Question 101. Is cell migration a selectable trait in the natural evolution of carcinoma?

The 150 most important questions in cancer research and clinical oncology series: questions 86-93 : Edited by Chinese Journal of Cancer

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which spark diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, 8 more questions are presented as follows. Question 86. In which circumstances is good supportive care associated with a survival advantage in patients with cancer? Question 87. Can we develop animal models to mimic immunotherapy response of cancer patients? Question 88. What are the mechanisms underlying hepatitis B virus-associated non-hepatocellular cancers? Question 89. Can we more precisely target tumor metabolism by identifying individual patients who would benefit from the treatment? Question 90. What type of cranial irradiation-based prophylactic therapy combination can dramatically improve the survival of patients with extensive small-cell lung cancer? Question 91. How can postoperative radiotherapy prolong overall survival of the patients with resected pIIIA-N2 non-small cell lung cancer? Question 92. What are the key molecular events that drive oral leukoplakia or erythroplakia into oral cancer? Question 93. How could we track the chemotherapeutics-driven evolution of tumor genome in non-small cell lung cancer for more effective treatment?

The 150 most important questions in cancer research and clinical oncology series: questions 76-85 : Edited by Chinese Journal of Cancer

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology to promote cancer research and accelerate collaborations. In this article, 10 questions are presented as followed. Question 76. How to develop effective therapeutics for cancer cachexia? Question 77. How can we develop preclinical animal models to recapitulate clinical situations of cancer patients for more effective anti-cancer drug development? Question 78. How can we develop novel effective therapeutics for pancreatic cancer and hepatocellular carcinoma? Question 79. What are the true beneficial mechanisms of antiangiogenic therapy in cancer patients? Question 80. How to approach the complex mechanisms of interplay among various cellular and molecular components in the tumor microenvironment? Question 81. Can tissue oxygenation improve the efficacy of conventional chemotherapy on cancer? Question 82. Can tissue oxygenation improve the efficacy of radiotherapy on digestive system tumors including liver cancer? Question 83. Can we integrate metabolic priming into multimodal management of liver cancer? Question 84. Has the limit of anti-androgen strategy in prostate cancer treatment been reached by the new generation of anti-androgen drugs? Question 85. Can we identify individuals with early-stage cancers via analyzing their clinical and non-clinical information collected from social media, shopping history, and clinical, pathological, and molecular traces?

The 150 most important questions in cancer research and clinical oncology series: questions 67-75 : Edited by Chinese Journal of Cancer

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which sparkle diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, 9 more questions are presented as followed. Question 67. How could we overcome the resistance of hepatocellular carcinoma against chemotherapeutics? Question 68. Is pursuit of non-covalent small-molecule binders of RAS proteins viable as a strategy of cancer drug discovery? Question 69. In what oligomeric structures do RAS proteins signal? Question 70. How can we achieve non-invasive early detection and diagnosis of lung cancer? Question 71. Does genetic information influence the volatolome enabling diagnosis of lung cancer with genetic mutations via cell headspace or breath analysis? Question 72. Is heavy ion beam radiotherapy effective to kill cancer stem cells? Question 73. Is there any diversity among different types of cancer in terms of sensitivity to heavy ion beam radiotherapy? Question 74. Can targeted alpha-particle therapy augment the effect of carbon ion radiotherapy on malignancies? Question 75. How does chromosomal instability drive tumor progression?

The 150 most important questions in cancer research and clinical oncology series: questions 57-66 : Edited by Chinese Journal of Cancer

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which sparkle diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, 10 more questions are presented as followed. Question 57. What are the major stresses that drive the formation, progression, and metastasis of a cancer? Question 58. What is the mechanism responsible for altering an acidic intracellular pH and a basic extracellular pH in normal tissue cells to a basic intracellular pH and an acidic extracellular pH in cancer cells, a fundamental and yet largely ignored phenomenon? Question 59. Where are the tumor-associated plasma microRNAs from in cancer patients? Question 60. Can we identify mechanisms employed by tumor subpopulations to evade standard therapies and seed relapse/metastatic tumors before treatment? Question 61. Why are mutation rates in epidermal growth factor receptor (EGFR) and erb-b2 receptor tyrosine kinase 2 (ERBB2) higher in lung cancer from never smokers than that from smokers? Question 62. Does tumor vasculogenic mimicry contribute to the resistance against antiangiogenic therapy in renal cancer? Question 63. What molecular targeted drugs would be effective for non-clear cell renal cell carcinoma (RCC), especially metastatic papillary RCC and chromophobe RCC? Question 64. Can it be more effective by targeting both the vascular endothelial growth factor receptor (VEGFR) and MET signaling pathways in sporadic metastatic papillary renal cell carcinoma (RCC)? Question 65. What are the predictive biomarkers that may be used to identify the renal cell carcinoma (RCC) patients who can benefit from immune checkpoint inhibitor treatment? Question 66. How do we identify predictive molecular biomarkers to stratify clear cell renal cell carcinoma patients for targeted therapies?

The 150 most important questions in cancer research and clinical oncology series: questions 50-56

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which sparkle diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, seven more questions are presented as followed. Question 50. When tumor cells spread from primary site to distant sites, are they required to be “trained” or “armed” in the bone marrow niche prior to colonizing soft tissues? Question 51. Are there tipping points during cancer progression which can be identified for manipulation? Question 52. Can we replace molecular biomarkers by network biomarkers? Question 53. Are conventional inhibitors of key cellular processes such as cell proliferation and differentiation more effective than targeted chemotherapeutics that antagonize the downstream cell signaling network via cell-surface receptors such as epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR) and c-Met, or intracellular receptors such as androgen receptor (AR) and estrogen receptor (ER), by drugs like erlotinib, sunitinib and cabozantinib, or enzalutamide and tomoxifen? Question 54. How can we robustly identify the candidate causal event of somatic genome alteration (SGA) by using computational approach? Question 55. How can we systematically reveal the immune evasion mechanism exploited by each tumor and utilize such information to guide targeted therapy to restore immune sensitivity? Question 56. Can the nasopharyngeal carcinoma (NPC) patients with sarcomatoid carcinoma (SC) subtype benefit from more specific targeted therapy?

The 150 most important questions in cancer research and clinical oncology series: questions 40-49

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which sparkle diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, 10 more questions are presented as followed. Question 40. Why do mice being used as tumorigenesis models raised in different places or different conditions possess different tumor formation rate? Question 41. How could we generate more effective anti-metastasis drugs? Question 42. What is the molecular mechanism underlying heterogeneity of cancer cachexia in patients with the same pathologic type? Question 43. Will patients with oligo-metastatic disease be curable by immunotherapy plus stereotactic body radiotherapy? Question 44. Can the Warburg effect regulation be targeted for cancer treatment? Question 45. Why do adenocarcinomas seldom occur in the small intestine? Question 46. Is Epstein–Barr virus infection a causal factor for nasal natural killer/T cell lymphoma formation? Question 47. Why will not all but very few human papillomavirus-infected patients eventually develop cervical cancer? Question 48. Why do cervical carcinomas induced by human papilloma virus have a low mutation rate in tumor suppressor genes? Question 49. Can viral infection trigger lung cancer relapse?

Chinese Journal of Cancer. The 150 most important questions in cancer research and clinical oncology series: questions 31-39 : Edited by Chinese Journal of Cancer

To accelerate our endeavors to overcome cancer, Chinese Journal of Cancer has launched a program of publishing 150 most important questions in cancer research and clinical oncology. In this article, 9 more questions are presented as follows. Question 31: How does aging process inhibit the formation of sarcoma? Question 32: Is intratumoral morphological heterogeneity the consequence of tumor genomic instability or the cause of aggressive tumor behavior? Can we identify more aggressive tumors by computationally analyzing the morphological heterogeneity of the tumor tissues? Question 33: How to pre-surgically differentiate irradiation-induced ulceration from cancerous ulceration? Question 34: Why is epidermal growth factor receptor (EGFR) 19 Del-positive tumor more sensitive to targeted therapy than EGFR 21 L858R-positive tumor in patients with non-small cell lung cancer? Question 35: Can an Epstein-Barr virus vaccine be developed to reduce the incidence of EBV-related malignancies? Question 36: What is the unique feature in sarcoma vasculature that causes the intrinsic resistance of sarcoma against anti-angiogenic therapy? Question 37: How many ways can sarcoma cells protect themselves from the attacks of cytotoxic drugs? Question 38: How stable does the tumor heterogeneity remain along with cytotoxic chemotherapy? Question 39: How to generate a prognostic classifier for diffuse low-grade gliomas by integrating genetic and epigenetic signatures with histological features?

The 150 most important questions in cancer research and clinical oncology series: Questions 25-30 : Edited by Chinese Journal of Cancer

To accelerate our endeavors to overcome cancer, Chinese Journal of Cancer has launched a program of publishing 150 most important questions in cancer research and clinical oncology. In this article, 6 more questions are presented as followed. Question 25: Does imprinting of immune responses to infections early in life predict future risk of childhood and adult cancers? Question 26: How to induce homogeneous tumor antigen expression in a heterogeneous tumor mass to enhance the efficacy of cancer immunotherapy? Question 27: Could we enhance the therapeutic effects of immunotherapy by targeting multiple tumor antigens simultaneously or sequentially? Question 28: Can immuno-targeting to cytokines halt cancer metastasis? Question 29: How can we dynamically and less-invasively monitor the activity of CD8⁺ T killer cells at tumor sites and draining lymph nodes? Question 30: How can the immune system destroy the niches for cancer initiation?