Regulation of fatty acid delivery to metastases by tumor endothelium

Tumor metastasis, the main cause of death in cancer patients, requires outgrowth of tumor cells after their dissemination and residence in microscopic niches. Nutrient sufficiency is a determinant of such outgrowth1. Fatty acids (FA) can be metabolized by cancer cells for their energetic and anabolic needs but impair the cytotoxicity of T cells in the tumor microenvironment (TME)2,3, thereby supporting metastatic progression. However, despite the important role of FA in metastatic outgrowth, the regulation of intratumoral FA is poorly understood. In this report, we show that tumor endothelium actively promotes tumor growth and restricts anti-tumor cytolysis by transferring FA into developing metastatic tumors. This process uses transendothelial fatty acid transport via endosome cargo trafficking in a mechanism that requires mTORC1 activity. Thus, tumor burden was significantly reduced upon endothelial-specific targeted deletion of Raptor, a unique component of the mTORC1 complex (RptorECKO). In vivo trafficking of a fluorescent palmitic acid analog to tumor cells and T cells was reduced in RptorECKO lung metastatic tumors, which correlated with improved markers of T cell cytotoxicity. Combination of anti-PD1 with RAD001/everolimus, at a low dose that selectively inhibits mTORC1 in endothelial cells4, impaired FA uptake in T cells and reduced metastatic disease, corresponding to improved anti-tumor immunity. These findings describe a novel mechanism of transendothelial fatty acid transfer into the TME during metastatic outgrowth and highlight a target for future development of therapeutic strategies.

Metabolic control of cancer metastasis: role of amino acids at secondary organ sites

Most cancer-related deaths are caused by the metastases, which commonly develop at multiple organ sites including the brain, bone, and lungs. Despite longstanding observations that the spread of cancer is not random, our understanding of the mechanisms that underlie metastatic spread to specific organs remains limited. However, metabolism has recently emerged as an important contributor to metastasis. Amino acids are a significant nutrient source to cancer cells and their metabolism which can serve to fuel biosynthetic pathways capable of facilitating cell survival and tumor expansion while also defending against oxidative stress. Compared to the primary tumor, each of the common metastatic sites exhibit vastly different nutrient compositions and environmental stressors, necessitating the need of cancer cells to metabolically thrive in their new environment during colonization and outgrowth. This review seeks to summarize the current literature on amino acid metabolism pathways that support metastasis to common secondary sites, including impacts on immune responses. Understanding the role of amino acids in secondary organ sites may offer opportunities for therapeutic inhibition of cancer metastasis.

Amino Acid Metabolism in Bone Metastatic Disease

PURPOSE OF REVIEW

Breast and prostate tumors frequently metastasize to the bone, but the underlying mechanisms for osteotropism remain elusive. An emerging feature of metastatic progression is metabolic adaptation of cancer cells to new environments. This review will summarize the recent advances on how cancer cells utilize amino acid metabolism during metastasis, from early dissemination to interactions with the bone microenvironment.

RECENT FINDINGS

Recent studies have suggested that certain metabolic preferences for amino acids may be associated with bone metastasis. Once in the bone microenvironment, cancer cells encounter a favorable microenvironment, where a changing nutrient composition of the tumor-bone microenvironment may alter metabolic interactions with bone-resident cells to further drive metastatic outgrowth. Enhanced amino acid metabolic programs are associated with bone metastatic disease and may be further augmented by the bone microenvironment. Additional studies are necessary to fully elucidate the role of amino acid metabolism on bone metastasis.

Loss of vascular endothelial glutaminase inhibits tumor growth and metastasis, and increases sensitivity to chemotherapy

Glutamine is the most abundant non-essential amino acid in blood stream; yet it's concentration in tumor interstitium is markedly lower than that in the serum, reflecting the huge demand of various cell types in tumor microenvironment for glutamine. While many studies have investigated glutamine metabolism in tumor epithelium and infiltrating immune cells, the role of glutamine metabolism in tumor blood vessels remains unknown. Here, we report that inducible genetic deletion of glutaminase (GLS) specifically in host endothelium, GLSECKO, impairs tumor growth and metastatic dissemination in vivo. Loss of GLS decreased tumor microvascular density, increased perivascular support cell coverage, improved perfusion, and reduced hypoxia in mammary tumors. Importantly, chemotherapeutic drug delivery and therapeutic efficacy were improved in tumor-bearing GLSECKO hosts or in combination with GLS inhibitor, CB839. Mechanistically, loss of GLS in tumor endothelium resulted in decreased leptin levels, and exogenous recombinant leptin rescued tumor growth defects in GLSECKO mice. Together, these data demonstrate that inhibition of endothelial glutamine metabolism normalizes tumor vessels, reducing tumor growth and metastatic spread, improving perfusion, and reducing hypoxia, and enhancing chemotherapeutic delivery. Thus, targeting glutamine metabolism in host vasculature may improve clinical outcome in patients with solid tumors.

Selective glutamine metabolism inhibition in tumor cells improves antitumor T lymphocyte activity in triple-negative breast cancer

Rapidly proliferating tumor and immune cells need metabolic programs that support energy and biomass production. The amino acid glutamine is consumed by effector T cells and glutamine-addicted triple-negative breast cancer (TNBC) cells, suggesting that a metabolic competition for glutamine may exist within the tumor microenvironment, potentially serving as a therapeutic intervention strategy. Here, we report that there is an inverse correlation between glutamine metabolic genes and markers of T cell-mediated cytotoxicity in human basal-like breast cancer (BLBC) patient data sets, with increased glutamine metabolism and decreased T cell cytotoxicity associated with poor survival. We found that tumor cell-specific loss of glutaminase (GLS), a key enzyme for glutamine metabolism, improved antitumor T cell activation in both a spontaneous mouse TNBC model and orthotopic grafts. The glutamine transporter inhibitor V-9302 selectively blocked glutamine uptake by TNBC cells but not CD8+ T cells, driving synthesis of glutathione, a major cellular antioxidant, to improve CD8+ T cell effector function. We propose a "glutamine steal" scenario, in which cancer cells deprive tumor-infiltrating lymphocytes of needed glutamine, thus impairing antitumor immune responses. Therefore, tumor-selective targeting of glutamine metabolism may be a promising therapeutic strategy in TNBC.

Phosphorylation of PLCγ1 by EphA2 Receptor Tyrosine Kinase Promotes Tumor Growth in Lung Cancer

EphA2 receptor tyrosine kinase (RTK) is often expressed at high levels in cancer and has been shown to regulate tumor growth and metastasis across multiple tumor types, including non-small cell lung cancer. A number of signaling pathways downstream of EphA2 RTK have been identified; however, mechanisms of EphA2 proximal downstream signals are less well characterized. In this study, we used a yeast-two-hybrid screen to identify phospholipase C gamma 1 (PLCγ1) as a novel EphA2 interactor. EphA2 interacts with PLCγ1 and the kinase activity of EphA2 was required for phosphorylation of PLCγ1. In human lung cancer cells, genetic or pharmacologic inhibition of EphA2 decreased phosphorylation of PLCγ1 and loss of PLCγ1 inhibited tumor cell growth in vitro. Knockout of PLCγ1 by CRISPR-mediated genome editing also impaired tumor growth in a KrasG12D-p53-Lkb1 murine lung tumor model. Collectively, these data show that the EphA2-PLCγ1 signaling axis promotes tumor growth of lung cancer and provides rationale for disruption of this signaling axis as a potential therapeutic option. IMPLICATIONS: The EphA2-PLCG1 signaling axis promotes tumor growth of non-small cell lung cancer and can potentially be targeted as a therapeutic option.

Microenvironmental Metabolism Regulates Antitumor Immunity

Metabolic reprogramming of cancer cells and the tumor microenvironment are emerging as key factors governing tumor growth, metastasis, and response to therapies including immune checkpoint inhibitors. It has been recognized that rapidly proliferating cancer cells, tumor-infiltrating lymphocytes, and vascular endothelial cells compete for oxygen and nutrients. Tumor cells and other cell types in the microenvironment not only compete for nutrients, but they also simultaneously produce immunosuppressive metabolites, leading to immune escape. In addition, commensal microbial metabolites can influence regulatory T cells and inflammation in the intestine, thus playing an essential role in cancer prevention or cancer promotion. In this review, we summarize recent advances on metabolic interactions among various cell types in the tumor microenvironment, with a focus on how these interactions affect tumor immunity. We also discuss the potential role of blood vessel metabolism in regulating immune cell trafficking and activation.

Disruption of the Scaffolding Function of mLST8 Selectively Inhibits mTORC2 Assembly and Function and Suppresses mTORC2-Dependent Tumor Growth In Vivo

mTOR is a serine/threonine kinase that acts in two distinct complexes, mTORC1 and mTORC2, and is dysregulated in many diseases including cancer. mLST8 is a shared component of both mTORC1 and mTORC2, yet little is known regarding how mLST8 contributes to assembly and activity of the mTOR complexes. Here we assessed mLST8 loss in a panel of normal and cancer cells and observed little to no impact on assembly or activity of mTORC1. However, mLST8 loss blocked mTOR association with mTORC2 cofactors RICTOR and SIN1, thus abrogating mTORC2 activity. Similarly, a single pair of mutations on mLST8 with a corresponding mutation on mTOR interfered with mTORC2 assembly and activity without affecting mTORC1. We also discovered a direct interaction between mLST8 and the NH₂-terminal domain of the mTORC2 cofactor SIN1. In PTEN-null prostate cancer xenografts, mLST8 mutations disrupting the mTOR interaction motif inhibited AKT S473 phosphorylation and decreased tumor cell proliferation and tumor growth in vivo. Together, these data suggest that the scaffolding function of mLST8 is critical for assembly and activity of mTORC2, but not mTORC1, an observation that could enable therapeutic mTORC2-selective inhibition as a therapeutic strategy. SIGNIFICANCE: These findings show that mLST8 functions as a scaffold to maintain mTORC2 integrity and kinase activity, unveiling a new avenue for development of mTORC2-specific inhibitors.

Abstract P2-02-02: The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ

Malignant tumors reprogram cellular metabolism to support cancer cell proliferation and survival. Although most cancers depend on a high rate of aerobic glycolysis, many cancer cells also display addiction to glutamine. Glutamine transporters and glutaminase activity are critical for glutamine metabolism in tumor cells, and upstream regulatory signaling pathways may represent a novel mechanism for targeted therapies in glutamine-addicted breast tumors such as Her2-overexpressing and triple-negative breast cancers (TNBC). We have found that the receptor tyrosine kinase EphA2 activated the transcriptional coactivators YAP and TAZ (YAP/TAZ), likely in a ligand-independent manner, to promote glutamine metabolism in cells and mouse models of breast cancer. Overexpression of EphA2 induced the nuclear accumulation of YAP and TAZ and increased the expression of YAP/TAZ target genes. Inhibition of the GTPase Rho or the kinase ROCK abolished EphA2-dependent YAP/TAZ nuclear localization. Silencing YAP or TAZ reduced the amount of intracellular glutamate through decreased expression of SLC1A5 and GLS, respectively, genes that encode proteins that promote glutamine uptake and metabolism. The regulatory DNA elements of both SLC1A5 and GLS contain the consensus sequence of the TEAD family of transcription factors that are closely associated with YAP/TAZ and were bound by TEAD4 in an EphA2-dependent manner. In patient breast cancer tissues, EphA2 expression positively correlated with that of YAP and TAZ, as well as that of GLS and SLC1A5. Although high expression of EphA2 predicted enhanced metastatic potential and poor patient survival, it also rendered breast cancer cells more sensitive to glutaminase inhibition. The findings define a previously unknown mechanism of EphA2-mediated glutaminolysis through YAP/TAZ activation in breast cancer and identify potential therapeutic targets in patients.

Citation Format: Edwards DN, Ngwa VM, Wang S, Shiuan E, Brantley-Sieders DM, Kim LC, Reynolds AB, Chen J. The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-02-02.

Abstract 1452: The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ

Malignant tumors reprogram cellular metabolism to support cancer cell proliferation and survival. Although most cancers depend on a high rate of aerobic glycolysis, many cancer cells also display addiction to glutamine. Glutamine transporters and glutaminase activity are critical for glutamine metabolism in tumor cells. We found that the receptor tyrosine kinase EphA2 activated the TEAD family transcriptional coactivators YAP and TAZ (YAP/TAZ), likely in a ligand-independent manner, to promote glutamine metabolism in cells and mouse models of HER2-positive breast cancer. Overexpression of EphA2 induced the nuclear accumulation of YAP and TAZ and increased the expression of YAP/TAZ target genes. Inhibition of the GTPase Rho or the kinase ROCK abolished EphA2-dependent YAP/TAZ nuclear localization. Silencing YAP or TAZ substantially reduced the amount of intracellular glutamate through decreased expression of SLC1A5 and GLS, respectively, genes that encode proteins that promote glutamine uptake and metabolism. The regulatory DNA elements of both SLC1A5 and GLS contain TEAD binding sites and were bound by TEAD4 in an EphA2-dependent manner. In patient breast cancer tissues, EphA2 expression positively correlated with that of YAP and TAZ, as well as that of GLS and SLC1A5. Although high expression or EphA2 predicted enhanced metastatic potential and poor patient survival, it also rendered HER2-positive breast cancer cells more sensitive to glutaminase inhibition. The findings define a previously unknown mechanism of EphA2-mediated glutaminolysis through YAP/TAZ activation in HER2-positive breast cancer and identify therapeutic targets in patients.

Citation Format: Deanna N. Edwards, Verra M. Ngwa, Shan Wang, Eileen Shiuan, Dana Brantley-Sieders, Laura Kim, Albert B. Reynolds, Jin Chen. The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1452.

The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ

Malignant tumors reprogram cellular metabolism to support cancer cell proliferation and survival. Although most cancers depend on a high rate of aerobic glycolysis, many cancer cells also display addiction to glutamine. Glutamine transporters and glutaminase activity are critical for glutamine metabolism in tumor cells. We found that the receptor tyrosine kinase EphA2 activated the TEAD family transcriptional coactivators YAP and TAZ (YAP/TAZ), likely in a ligand-independent manner, to promote glutamine metabolism in cells and mouse models of HER2-positive breast cancer. Overexpression of EphA2 induced the nuclear accumulation of YAP and TAZ and increased the expression of YAP/TAZ target genes. Inhibition of the GTPase Rho or the kinase ROCK abolished EphA2-dependent YAP/TAZ nuclear localization. Silencing YAP or TAZ substantially reduced the amount of intracellular glutamate through decreased expression of SLC1A5 and GLS, respectively, genes that encode proteins that promote glutamine uptake and metabolism. The regulatory DNA elements of both SLC1A5 and GLS contain TEAD binding sites and were bound by TEAD4 in an EphA2-dependent manner. In patient breast cancer tissues, EphA2 expression positively correlated with that of YAP and TAZ, as well as that of GLS and SLC1A5 Although high expression of EphA2 predicted enhanced metastatic potential and poor patient survival, it also rendered HER2-positive breast cancer cells more sensitive to glutaminase inhibition. The findings define a previously unknown mechanism of EphA2-mediated glutaminolysis through YAP/TAZ activation in HER2-positive breast cancer and identify potential therapeutic targets in patients.

The Ephrin-A1/EPHA2 Signaling Axis Regulates Glutamine Metabolism in HER2-Positive Breast Cancer

Dysregulation of receptor tyrosine kinases (RTK) contributes to cellular transformation and cancer progression by disrupting key metabolic signaling pathways. The EPHA2 RTK is overexpressed in aggressive forms of breast cancer, including the HER2(+) subtype, and correlates with poor prognosis. However, the role of EPHA2 in tumor metabolism remains unexplored. In this study, we used in vivo and in vitro models of HER2-overexpressing breast cancer to investigate the mechanisms by which EPHA2 ligand-independent signaling promotes tumorigenesis in the absence of its prototypic ligand, ephrin-A1. We demonstrate that ephrin-A1 loss leads to upregulated glutamine metabolism and lipid accumulation that enhanced tumor growth. Global metabolic profiling of ephrin-A1-null, HER2-overexpressing mammary tumors revealed a significant increase in glutaminolysis, a critical metabolic pathway that generates intermediates for lipogenesis. Pharmacologic inhibition of glutaminase activity reduced tumor growth in both ephrin-A1-depleted and EPHA2-overexpressing tumor allografts in vivo Mechanistically, we show that the enhanced proliferation and glutaminolysis in the absence of ephrin-A1 were attributed to increased RhoA-dependent glutaminase activity. EPHA2 depletion or pharmacologic inhibition of Rho, glutaminase, or fatty acid synthase abrogated the increased lipid content and proliferative effects of ephrin-A1 knockdown. Together, these findings highlight a novel, unsuspected connection between the EPHA2/ephrin-A1 signaling axis and tumor metabolism, and suggest potential new therapeutic targets in cancer subtypes exhibiting glutamine dependency. Cancer Res; 76(7); 1825-36. ©2016 AACR.

Strand exchange of telomeric DNA catalyzed by the Werner syndrome protein (WRN) is specifically stimulated by TRF2

Werner syndrome (WS), caused by loss of function of the RecQ helicase WRN, is a hereditary disease characterized by premature aging and elevated cancer incidence. WRN has DNA binding, exonuclease, ATPase, helicase and strand annealing activities, suggesting possible roles in recombination-related processes. Evidence indicates that WRN deficiency causes telomeric abnormalities that likely underlie early onset of aging phenotypes in WS. Furthermore, TRF2, a protein essential for telomere protection, interacts with WRN and influences its basic helicase and exonuclease activities. However, these studies provided little insight into WRN's specific function at telomeres. Here, we explored the possibility that WRN and TRF2 cooperate during telomeric recombination processes. Our results indicate that TRF2, through its interactions with both WRN and telomeric DNA, stimulates WRN-mediated strand exchange specifically between telomeric substrates; TRF2's basic domain is particularly important for this stimulation. Although TRF1 binds telomeric DNA with similar affinity, it has minimal effects on WRN-mediated strand exchange of telomeric DNA. Moreover, TRF2 is displaced from telomeric DNA by WRN, independent of its ATPase and helicase activities. Together, these results suggest that TRF2 and WRN act coordinately during telomeric recombination processes, consistent with certain telomeric abnormalities associated with alteration of WRN function.

Intramolecular telomeric G-quadruplexes dramatically inhibit DNA synthesis by replicative and translesion polymerases, revealing their potential to lead to genetic change

Recent research indicates that hundreds of thousands of G-rich sequences within the human genome have the potential to form secondary structures known as G-quadruplexes. Telomeric regions, consisting of long arrays of TTAGGG/AATCCC repeats, are among the most likely areas in which these structures might form. Since G-quadruplexes assemble from certain G-rich single-stranded sequences, they might arise when duplex DNA is unwound such as during replication. Coincidentally, these bulky structures when present in the DNA template might also hinder the action of DNA polymerases. In this study, single-stranded telomeric templates with the potential to form G-quadruplexes were examined for their effects on a variety of replicative and translesion DNA polymerases from humans and lower organisms. Our results demonstrate that single-stranded templates containing four telomeric GGG runs fold into intramolecular G-quadruplex structures. These intramolecular G quadruplexes are somewhat dynamic in nature and stabilized by increasing KCl concentrations and decreasing temperatures. Furthermore, the presence of these intramolecular G-quadruplexes in the template dramatically inhibits DNA synthesis by various DNA polymerases, including the human polymerase δ employed during lagging strand replication of G-rich telomeric strands and several human translesion DNA polymerases potentially recruited to sites of replication blockage. Notably, misincorporation of nucleotides is observed when certain translesion polymerases are employed on substrates containing intramolecular G-quadruplexes, as is extension of the resulting mismatched base pairs upon dynamic unfolding of this secondary structure. These findings reveal the potential for blockage of DNA replication and genetic changes related to sequences capable of forming intramolecular G-quadruplexes.

Detection of palm fruit lipids in archaeological pottery from Qasr Ibrim, Egyptian Nubia

In modern times, the trees of the palm family have been of great economic and social importance to the people in Egypt, as in other parts of the world. There are various species of palm and although different parts of the tree can be used, the fruit are of great value. In antiquity, it is expected that the palm fruit would also have been of great importance to people in the region. The chemical analysis of absorbed residues in archaeological pottery is well established, and through the investigation of ceramic vessels (via gas chromatography, gas chromatography-mass spectrometry and gas chromatography-combustion-isotope ratio mass spectrometry) saturated carboxylic acids in the range C12 to C18 have been detected (with an unusually high abundance of C12) from vessels from the Nubian site of Qasr Ibrim. This is mirrored in the saturated fatty acid distributions detected from the kernels of modern and ancient date palm (Phoenix dactylifera L.) and dom palm (Hyphaena thebaica (L.) Mart.). Mixing in some of the vessels of the palm fruit with another lipid source is indicated through the delta13C values. These results provide the first direct evidence for the exploitation of palm fruit in antiquity and the use of pottery vessels in its processing.

Crisis phenomena among African adolescents

This study investigated inadequate parent-child relationships, problems with regard to sexuality, and substance abuse among African university students. They reported experiencing positive aspects of the parent-child relationship, such as acceptance, love, understanding, encouragement, and guidance, as well as negative aspects, including inadequate communication and parents' authoritarian attitudes. Numerous sexual issues and the abuse of alcohol and other drugs were perceived as serious problems among teenagers in general. Although an inadequate parent-child relationship appears to contribute to substance abuse and sexuality problems, it cannot be regarded as solely responsible, as a multitude of factors also play a role. The results indicate the need for life-skills training for both adolescents and parents, particularly regarding communication.

An activity-dependent network of interactions links the Rel protein Dorsal with its cytoplasmic regulators

A signaling pathway active on the ventral side of the Drosophila embryo defines dorsoventral polarity. A cell surface signal relayed by Toll, Tube and Pelle releases the Rel-related protein Dorsal from its cytoplasmic inhibitor Cactus; free Dorsal translocates into nuclei and directs expression of ventral fates. Using the yeast two-hybrid system and immunoprecipitation experiments, we define scaffolding and anchoring interactions among the pathway components. We show that Dorsal binds specifically to Tube, Pelle and Cactus, and that the protein kinase activity of Pelle differentially regulates its interactions with Dorsal and Tube. We also identify Drosophila Filamin as a potential adaptor linking the interaction network, via Tube, to the transmembrane receptor Toll.

Interaction of the pelle kinase with the membrane-associated protein tube is required for transduction of the dorsoventral signal in Drosophila embryos

Within the Drosophila embryo, tube and the protein kinase pelle transduce an intracellular signal generated by the transmembrane receptor Toll. This signal directs import of the rel-related protein dorsal into ventral and ventrolateral nuclei, thereby establishing dorsoventral polarity. We show by immunolocalization that tube protein associates with the plasma membrane during interphase. We also find that tube sequences required for signaling interact with pelle in a yeast two-hybrid assay. We demonstrate that fusion of the pelle catalytic domain to the transmembrane receptor torso is sufficient to induce ventral fates; this activity is independent of Toll or tube. Lastly, we find that fusion of the tube protein to torso also induces ventral fates, but only in the presence of functional pelle. We propose a model wherein tube activates pelle by recruiting it to the plasma membrane, thereby propagating the axis-determining signal.

Histological grade and other prognostic factors in relation to survival of patients with breast cancer

Records of 3085 patients registered with breast cancer at the Mersey Regional Cancer Registry have been analysed to evaluate the relative importance of possible prognostic factors. In a subgroup of 1759 patients, clinical stage and histological grade are shown to be strongly related to survival after treatment. In addition histological grade is related to the distribution of times to death after treatment. The results of this and 3 other studies have implications for the design and analysis of clinical trials in the primary treatment of breast cancer.

The treatment of carcinoma in situ of the uterine cervix in the Mersey Regional Cancer Registry Area with some comments on incidence

One thousand and twenty-four patients were registered with carcinoma in situ of the cervix at the Mersey Regional Cancer Registry from 1962 to 1973. The number of new cases reached a peak in the over-35s during 1968-70, but later in the under-35s. Fifty-five per cent of patients were treated initially by hysterectomy and 39% by cone biopsy or amputation. In the former group two patients developed invasive recurrence and one patient in situ recurrence. In the latter group one patient developed invasive recurrence and 15 patients developed in situ recurrence. This evidence is in agreement with other studies and supports the view that cone biopsy is an effective treatment for c. in situ of the cervix.

Sex dependence of human intracranial gliomata

The age and sex distribution of 1223 cases of intracranial gliomata, diagnosed in the geographical area covered by the Mersey Regional Cancer Registry over the period 1961-70, are analysed. In children and adults, the intracranial gliomata predominates in males, the tumour incidence figures indicating a ratio of 3 : 2. For young adults, the tumour incidence increases with age and is approximately the same in males and females. It is not until the age group 45-49 years is reached that the tumour incidence in males is higher. The peak tumour incidence occurs at the same age in both sexes (60-64 years) and thereafter incidence declines with age. These results are compared with previously published human data, and with the findings of experimental studies in the rat. Factors including naturally occurring changes in the hormone levels are discussed, in an attempt to explain the observed age-related sex differences.