Synergistic antitumor activity by dual blockade of CCR1 and CXCR2 expressed on myeloid cells within the tumor microenvironment.

BACKGROUND: Chemokine signaling within the tumor microenvironment can promote tumor progression. Although CCR1 and CXCR2 on myeloid cells could be involved in tumor progression, it remains elusive what effect would be observed if both of those are blocked. METHODS: We employed two syngeneic colorectal cancer mouse models: a transplanted tumor model and a liver metastasis model. We generated double-knockout mice for CCR1 and CXCR2, and performed bone marrow (BM) transfer experiments in which sub-lethally irradiated wild-type mice were reconstituted with BM from either wild-type, Ccr1-/-, Cxcr2-/- or Ccr1-/-Cxcr2-/- mice. RESULTS: Myeloid cells that express MMP2, MMP9 and VEGF were accumulated around both types of tumors through CCR1- and CXCR2-mediated pathways. Mice reconstituted with Ccr1-/-Cxcr2-/- BM exhibited the strongest suppression of tumor growth and liver metastasis compared with other three groups. Depletion of CCR1+CXCR2+ myeloid cells led to a higher frequency of CD8+ T cells, whereas the numbers of Ly6G+ neutrophils, FOXP3+ Treg cells and CD31+ endothelial cells were significantly decreased. Furthermore, treatment with a neutralizing anti-CCR1 mAb to mice reconstituted with Cxcr2-/- BM significantly suppressed tumor growth and liver metastasis. CONCLUSION: Dual blockade of CCR1 and CXCR2 pathways in myeloid cells could be an effective therapy against colorectal cancer.

Downregulation of osteoprotegerin in colorectal cancer cells promotes liver metastasis via activating tumor-associated macrophage.

Osteoprotegerin (OPG) is a secreted cytokine that functions as a decoy receptor for receptor activator of nuclear factor kappa-B (RANK) ligand (RANKL). Anti-RANKL treatment for bone metastasis has been widely accepted for solid tumors. However, the mechanism of OPG-RANKL-RANK signaling in systemic colorectal cancer (CRC) metastasis remains unclear. In this study, we investigated the relevance and function of OPG expression in CRC liver metastasis. First, we performed in silico analysis using The Cancer Genome Atlas public database and found that lower OPG expression in CRC was associated with poor overall survival. Immunohistochemistry analyses using resected specimen from patients with CRC in our institute confirmed the result. Patient-matched primary CRC and liver metastases showed a significant downregulation of OPG expression in metastatic lesions. In CRC cell lines, OPG expression did not suppress cell proliferation and migration. However, OPG expression inhibited macrophage migration by suppressing the RANKL-RANK pathway. Moreover, in vivo mouse liver metastasis models showed that OPG expression in CRC cells suppressed liver metastases. In addition, treatment with an anti-RANKL neutralizing antibody also suppressed liver metastases. These results showed that downregulation of OPG expression in CRC cells promotes liver metastasis by activating tumor-associated macrophage, which can become a candidate for targeted therapy with anti-RANKL neutralizing antibody for CRC liver metastasis.

Neutrophil Extracellular Traps Promote Metastases of Colorectal Cancers through Activation of ERK Signaling by Releasing Neutrophil Elastase.

Neutrophil extracellular traps (NETs) play important roles in host immunity, as there is increasing evidence of their contribution to the progression of several types of cancers even though their role in colorectal cancers (CRCs) remains unclear. To investigate the clinical relevance of NETs in CRCs, we examined the expression of citrullinated histone H3 using immunohistochemistry and preoperative serum myeloperoxidase-DNA complexes in CRC patients using an enzyme-linked immunosorbent assay. High expression of intratumoral or systemic NETs was found to correlate with poor relapse-free survival (RFS), for which it is an independent prognostic factor. In vitro investigations of CRC cells (HCT116, HT29) revealed that NETs did not affect their proliferation but did promote the migration of CRC cells mediated by neutrophil elastase (NE) released during NETosis to increase extracellular signal-regulated kinase (ERK) activity. In vivo experiments using nude mice (KSN/slc) revealed that NE inhibition suppressed liver metastases in CRC cells, although it did not affect the growth of subcutaneously implanted tumors. Taken together, these results suggest that NET formation correlates with poor prognoses of patients with CRC and that the inhibition of NE could be a potential therapy for CRC metastases.

Dual blockade of macropinocytosis and asparagine bioavailability shows synergistic anti-tumor effects on KRAS-mutant colorectal cancer.

Mutations of KRAS gene are found in various types of cancer, including colorectal cancer (CRC). Despite intense efforts, no pharmacological approaches are expected to be effective against KRAS-mutant cancers. Macropinocytosis is an evolutionarily conserved actin-dependent endocytic process that internalizes extracellular fluids into large vesicles called macropinosomes. Recent studies have revealed macropinocytosis's important role in metabolic adaptation to nutrient stress in cancer cells harboring KRAS mutations. Here we showed that KRAS-mutant CRC cells enhanced macropinocytosis for tumor growth under nutrient-depleted conditions. We also demonstrated that activation of Rac1 and phosphoinositide 3-kinase were involved in macropinocytosis of KRAS-mutant CRC cells. Furthermore, we found that macropinocytosis was closely correlated with asparagine metabolism. In KRAS-mutant CRC cells engineered with knockdown of asparagine synthetase, macropinocytosis was accelerated under glutamine-depleted condition, and albumin addition could restore the glutamine depletion-induced growth suppression by recovering the intracellular asparagine level. Finally, we discovered that the combination of macropinocytosis inhibition and asparagine depletion dramatically suppressed the tumor growth of KRAS-mutant CRC cells in vivo. These results indicate that dual blockade of macropinocytosis and asparagine bioavailability could be a novel therapeutic strategy for KRAS-mutant cancers.

[Rupture of Ovarian Metastasis from Cecal Cancer during Chemotherapy - A Case Report Suggestive of Bilateral Salpingo-Oophorectomy].

A 66-year-old woman was diagnosed with advanced cecal cancer with metastases to her right ovary, peritoneum, and liver. Ileocecal resection and right salpingo-oophorectomy were performed as cytoreduction surgery before systemic chemotherapy. The colon cancer metastasized to her left ovary during chemotherapy and grew rapidly until it ruptured spontaneously, although the other metastases sites continued to respond to treatment. Emergent left salpingo-oophorectomy was performed. Pathological findings confirmed ovarian metastasis from colon cancer. Ovarian metastases are less responsive to systemic chemotherapy compared to extra-ovarian metastasis and the rapid growth sometimes occurs as a related symptom. Bilateral salpingo-oophorectomy might be recommended in cytoreduction surgery even if the ovarian metastasis is unilateral.

Successful oral desensitization with crizotinib after crizotinib-induced hepatitis in an anaplastic lymphoma kinase-rearranged non-small-cell lung cancer patient: A case report.

Crizotinib is one of the molecularly-targeted agents targeted against anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC). Although its effects appear to be promising, crizotinib may cause adverse effects in patients with ALK-rearranged NSCLC. Hepatic laboratory abnormalities are frequently observed with crizotinib and treatment discontinuation is occasionally required. We herein report the case of a 51-year-old woman diagnosed with relapsed ALK-rearranged NSCLC, who received crizotinib as second-line systemic chemotherapy. After 17 days of crizotinib therapy, the patient developed grade >3 hepatotoxicity. Treatment discontinuation improved the laboratory abnormalities and fifth-line oral desensitization with crizotinib achieved successful response without hepatotoxicity. Therefore, oral desensitization with crizotinib may be a viable option following crizotinib-induced hepatitis.

Multi-modal treatment of primarily using continuous subcutaneous interferon-alpha injection in combination with surgery and/or radiotherapy.

PURPOSE: Thirty-nine renal cell carcinoma patients with bony metastasis were intensively treated, primarily with immunotherapy using natural type interferon-alpha (IFN-alpha) continuous subcutaneous injection in combination with surgical resection and radiation therapy. Long-term survival was achieved, including three patients with complete response. The results of this study are presented. METHODS: The mode of administration of IFN-alpha was as follows: natural-type IFN-alpha (25,000,000 IU) was dissolved in 60 mL of distilled water and administered via continuous subcutaneous injection (0.5 mL/h) as 'one course of the treatment'. Two courses of IFN-alpha therapy were given 2 weeks preoperatively, while 13 courses of IFN-alpha therapy were given postoperatively (one course per week). Thus, 15 courses of IFN-alpha therapy were administered during the trial period. Thereafter, IFN-alpha therapy was repeated either every week or every other week depending on the condition of the patient. Additionally, blood levels of IFN-alpha were monitored for four patients following initiation of IFN-alpha continuous subcutaneous injection therapy. RESULTS: Immediately after injection of IFN-alpha, blood levels of IFN-alpha started to rise, reaching 40.5 IU/mL on average at 24 h after initiation of IFN-alpha therapy. Thereafter, blood levels of IFN-alpha remained high and measurable blood levels of IFN-alpha were maintained for up to 24 h after completion of IFN-alpha injection. As a whole, IFN-alpha was detectable for 6-8 days and Cmax (maximum blood concentration of IFN) was 167 IU/mL. Thirty-nine patients with bony metastases were treated as follows: IFN mono-therapy (19 patients), IFN and radiation therapy (15 patients) and IFN and surgical resection of bony metastases (five patients). Fourteen patients survived and the details of these 14 patients are as follows: complete response in three cases, partial response in two, no change in six and progressive disease in three. Twenty-five patients died of renal cell carcinoma. The overall 5-year survival rate was 35.0%. CONCLUSIONS: These findings indicate that IFN-alpha continuous subcutaneous injection therapy is a useful modality for renal cell carcinoma patients with bony metastasis if administered in combination of radical nephrectomy and radiation therapy.

Transperineal ultrasound-guided 12-core systematic biopsy of the prostate for patients with a prostate-specific antigen level of 2.5-20 ng/ml in Japan.

BACKGROUND: The aim of this study was to investigate the cancer detection rate in patients with a prostate-specific antigen (PSA) level of 2.5 to 20 ng/ml, using transperineal ultrasound-guided systematic biopsy of the prostate. METHODS: Three hundred consecutive patients with PSA levels of 2.5 to 20 ng/ml underwent transperineal ultrasound-guided 12-core systematic biopsy of the prostate. RESULTS: Prostate cancer was detected in 108 of the 300 patients (36.0%). The cancer detection rates in patients with total PSA levels of 2.5-4.0, 4.01-10.0 and 10.01-20.0 ng/ml were 18.2%, 31.0%, and 50.0%, respectively. The cancer detection rates in patients with prostate volumes of less than 30 cc and over 50 cc were almost 50%, and 13.3%, respectively. The cancer detection rate in patients with a PSA density (PSAD) of less than 0.10 ng/ml per cc was only 5.6%, and no prostate cancer was detected in patients with a free-to-total PSA ratio (% f PSA) over 40%. CONCLUSION: We demonstrated a high prostate cancer detection rate by the transperineal ultrasound-guided 12-core systematic biopsy method in patients with PSA levels of 2.5 to 20 ng/ml. Accordingly, if the number of core biopsies is further increased overall, except in patients with a large prostate volume, and if the indication for biopsy is decided based on the PSAD and %f PSA, then the cancer detection rate by the present method may be further improved, with fewer unnecessary biopsies.